WO2021168715A1

WO2021168715A1 - Method, apparatus and system for discovering application

Info

Publication number: WO2021168715A1
Application number: PCT/CN2020/076857
Authority: WO
Inventors: 朱方园; 陈中平; 倪慧; 李岩
Original assignee: 华为技术有限公司
Priority date: 2020-02-26
Filing date: 2020-02-26
Publication date: 2021-09-02

Abstract

Disclosed are a method, apparatus and system for discovering an application. The method comprises: a session management function network element obtains first information; the session management function network element determines second information at least according to the first information and position information of a terminal device; and the session management function network element sends a first domain name and the second information to a first user plane network element. The first information comprises an identifier of a first application corresponding to the first domain name and position information of at least one application platform where the first application is, and the second information is used for obtaining a first IP address corresponding to the first domain name. By adopting the method, the terminal device can access local service nearby when requesting, at a position indicated by the position information of the terminal device, to access the first domain name, a shorter delay for accessing the service can be achieved, thereby ensuring high communication efficiency.

Description

一种发现应用的方法、装置及***Method, device and system for discovering applications

技术领域Technical field

本申请涉及通信技术领域，尤其涉及一种发现应用的方法、装置及***。This application relates to the field of communication technology, and in particular to a method, device, and system for discovering applications.

背景技术Background technique

随着移动终端(例如，手机)用户数量的不断增长，各类移动终端支持的业务功能不断增加，例如即时通信、证券、网页浏览、文件下载等功能已逐步成为终端设备，尤其是智能手机的主流应用。在上网过程中，终端设备需要查询完全限定域名(fully qualified domain name，FQDN)对应的互联网协议(internet protocol，IP)地址，以便发送数据包。通常，终端设备可以向域名***(domain name system，DNS)服务器发送域名解析请求，该域名解析请求携带所需查询的域名，由DNS服务器返回该域名对应的IP地址，进而终端设备可以通过该IP地址访问该域名。With the continuous increase in the number of users of mobile terminals (for example, mobile phones), the business functions supported by various mobile terminals continue to increase. For example, functions such as instant messaging, securities, web browsing, and file download have gradually become terminal devices, especially smartphones. Mainstream application. In the process of surfing the Internet, the terminal device needs to query the Internet Protocol (IP) address corresponding to the fully qualified domain name (FQDN) in order to send data packets. Generally, a terminal device can send a domain name resolution request to a domain name system (DNS) server. The domain name resolution request carries the domain name to be queried. The DNS server returns the IP address corresponding to the domain name, and the terminal device can pass the IP address Address to access the domain name.

移动边缘计算(mobile edge computing，MEC)技术可以将接入网与互联网业务深度融合。它将应用服务器(application server，AS)和移动宽带(mobile broadband，MBB)核心网部分业务处理和资源调度的功能一同部署到靠近接入网的网络边缘，通过业务靠近用户处理，来提供可靠、超低时延的极致业务体验。例如在第五代(5rd generation，5G)演进架构下，终端设备将域名解析请求通过连接MEC平台的用户面功能(user plane funtion，UPF)网元发送给DNS服务器。然而，由于部署在不同MEC平台上提供相同服务的应用服务器具有相同的域名，而这些应用服务器具有不同的IP地址，DNS服务器如何将距离终端设备较近的应用服务器的IP地址返回给终端设备以使得终端设备能够就近访问本地业务，是目前亟待解决的问题。Mobile edge computing (MEC) technology can deeply integrate access networks and Internet services. It deploys application server (AS) and mobile broadband (mobile broadband, MBB) core network service processing and resource scheduling functions together to the network edge close to the access network, and provides reliable, The ultimate service experience with ultra-low latency. For example, in the 5th generation (5G) evolution architecture, a terminal device sends a domain name resolution request to a DNS server through a user plane funtion (UPF) network element connected to the MEC platform. However, because the application servers deployed on different MEC platforms to provide the same service have the same domain name, and these application servers have different IP addresses, how does the DNS server return the IP addresses of the application servers closer to the terminal device to the terminal device? Enabling terminal devices to access local services nearby is a problem to be solved urgently at present.

发明内容Summary of the invention

本申请实施例提供一种发现应用的方法、装置及***，用于实现DNS服务器将距离终端设备较近的应用服务器的IP地址返回给终端设备以使得终端设备能够就近访问本地业务。The embodiments of the present application provide a method, device, and system for discovering applications, which are used to realize that the DNS server returns the IP address of the application server closer to the terminal device to the terminal device so that the terminal device can access local services nearby.

第一方面，本申请实施例提供一种发现应用的方法，该方法包括：会话管理功能网元获取第一信息，会话管理功能网元至少根据所述第一信息和终端设备的位置信息确定第二信息，会话管理功能网元向第一用户面网元发送所述第一域名和所述第二信息。其中，所述第一信息包括第一域名对应的第一应用的标识和所述第一应用所在的至少一个应用平台的位置信息，所述第二信息用于获取所述第一域名对应的第一IP地址。In the first aspect, an embodiment of the present application provides a method for discovering applications. The method includes: a session management function network element obtains first information, and the session management function network element determines the first information at least according to the first information and the location information of the terminal device. Second information, the session management function network element sends the first domain name and the second information to the first user plane network element. Wherein, the first information includes the identifier of the first application corresponding to the first domain name and the location information of at least one application platform where the first application is located, and the second information is used to obtain the first application corresponding to the first domain name. An IP address.

采用上述方法，会话管理功能网元获取第一信息，至少根据终端设备的位置信息和第一信息确定第二信息，并向第一用户面网元发送第一域名和第二信息，可以实现当终端设备在终端设备的位置信息所指示的位置请求访问第一域名时，能够就近访问本地业务，可以实现访问业务的时延较短，进而可以保证较高通信效率。Using the above method, the session management function network element obtains the first information, determines the second information at least according to the location information of the terminal device and the first information, and sends the first domain name and the second information to the first user plane network element, which can realize the current When the terminal device requests access to the first domain name at the location indicated by the location information of the terminal device, it can access the local service nearby, which can achieve a short delay in accessing the service, thereby ensuring higher communication efficiency.

在一种可能的设计中，所述会话管理功能网元根据所述第一信息和所述终端设备的位置信息，在所述第一应用所在的至少一个应用平台中确定第一应用平台，其中，所述第二信息与所述第一应用平台对应。In a possible design, the session management function network element determines a first application platform in at least one application platform where the first application is located according to the first information and the location information of the terminal device, where , The second information corresponds to the first application platform.

采用上述设计可以实现会话管理功能网元根据终端设备的位置信息和第一信息从第一应用所在的至少一个应用平台中确定一个应用平台。By adopting the above design, the network element with the session management function can determine an application platform from at least one application platform where the first application is located according to the location information of the terminal device and the first information.

在一种可能的设计中，所述第一应用所在的至少一个应用平台的位置信息包括所述第一应用所在的至少一个应用平台分别对应的数据网络接入标识DNAI。In a possible design, the location information of the at least one application platform where the first application is located includes data network access identifiers DNAI respectively corresponding to the at least one application platform where the first application is located.

在一种可能的设计中，所述第二信息包括所述第一应用平台对应的DNAI。In a possible design, the second information includes DNAI corresponding to the first application platform.

采用上述设计可以用于使DNS服务器确定距离终端设备较近的应用平台，并进一步确定该应用平台上部署的第一应用的服务器的IP地址作为第一域名对应的第一IP地址。The above design can be used to make the DNS server determine the application platform closer to the terminal device, and further determine the IP address of the server of the first application deployed on the application platform as the first IP address corresponding to the first domain name.

在一种可能的设计中，所述第一信息还包括：所述第一应用所在的至少一个应用平台分别对应的IP地址；所述会话管理功能网元根据所述第一应用平台和所述第一应用所在的至少一个应用平台分别对应的IP地址确定所述第二信息，所述第二信息包括所述第一应用平台对应的IP地址。In a possible design, the first information further includes: IP addresses corresponding to at least one application platform where the first application is located; the session management function network element is based on the first application platform and the The IP addresses respectively corresponding to at least one application platform where the first application is located determine the second information, and the second information includes the IP address corresponding to the first application platform.

在一种可能的设计中，所述第一信息还包括所述第一应用所在的至少一个应用平台分别对应的本地域名***DNS服务器的IP地址；所述会话管理功能网元根据所述第一应用平台和所述第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址确定所述第二信息，所述第二信息包括第一本地DNS服务器的IP地址，其中，所述第一本地DNS服务器为所述第一应用平台提供服务。In a possible design, the first information further includes the IP addresses of the local domain name system DNS servers respectively corresponding to at least one application platform where the first application is located; the session management function network element is based on the first application The application platform and the IP address of the local DNS server respectively corresponding to the at least one application platform on which the first application is located determine the second information, and the second information includes the IP address of the first local DNS server, wherein the first A local DNS server provides services for the first application platform.

采用上述设计可以用于确定第一本地DNS服务器，以使第一本地DNS服务器确定距离终端设备较近的应用平台，并进一步确定该应用平台上部署的第一应用的服务器的IP地址作为第一域名对应的第一IP地址。The above design can be used to determine the first local DNS server, so that the first local DNS server determines the application platform closer to the terminal device, and further determines the IP address of the server of the first application deployed on the application platform as the first The first IP address corresponding to the domain name.

在一种可能的设计中，所述第一信息还包括所述第一应用所在的至少一个应用平台分别对应的索引信息所述会话管理功能网元根据所述第一信息确定第三信息，向所述第一用户面网元发送所述第三信息；所述会话管理功能网元根据所述第一应用平台的DNAI和所述第一应用所在的至少一个应用平台分别对应的索引信息确定第二信息。其中，所述第二信息包括所述第一应用平台对应的DNAI对应的索引信息，所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的DNAI与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系。In a possible design, the first information further includes index information corresponding to at least one application platform where the first application is located, and the session management function network element determines the third information according to the first information, and The first user plane network element sends the third information; the session management function network element determines the second information according to the DNAI of the first application platform and the index information corresponding to at least one application platform on which the first application is located. Two information. Wherein, the second information includes index information corresponding to the DNAI corresponding to the first application platform, and the third information includes the DNAI corresponding to the at least one application platform where the first application is located and where the first application is located. Correspondence relationship of index information corresponding to at least one application platform of.

在一种可能的设计中，所述第一信息还包括所述第一应用所在的至少一个应用平台分别对应的索引信息和所述第一应用所在的至少一个应用平台分别对应的IP地址；所述会话管理功能网元根据所述第一信息确定第三信息，向所述第一用户面网元发送所述第三信息；所述会话管理功能网元根据所述第一应用平台、所述第一应用所在的至少一个应用平台分别对应的IP地址和所述第一应用所在的至少一个应用平台分别对应的索引信息确定所述第二信息。其中，所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的IP地址与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系，所述第二信息包括所述第一应用平台对应的IP地址对应的索引信息。In a possible design, the first information further includes index information corresponding to at least one application platform on which the first application is located and an IP address corresponding to at least one application platform on which the first application is located; The session management function network element determines third information according to the first information, and sends the third information to the first user plane network element; the session management function network element determines the third information according to the first application platform, the The second information is determined by the IP address respectively corresponding to the at least one application platform where the first application is located and the index information respectively corresponding to the at least one application platform where the first application is located. Wherein, the third information includes a correspondence between an IP address corresponding to at least one application platform where the first application is located and index information corresponding to at least one application platform where the first application is located, and the second information The index information corresponding to the IP address corresponding to the first application platform is included.

在一种可能的设计中，所述第一信息还包括所述第一应用所在的至少一个应用平台分别对应的索引信息和所述第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址；所述会话管理功能网元根据所述第一信息确定第三信息，向所述第一用户面网元发送所述第三信息；所述会话管理功能网元根据所述第一应用平台、所述第一应用所在的至少一个应用平台分别对应的索引信息和所述第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址确定所述第二信息。其中，所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系，所述第二信息包括第一本地DNS服务器的IP地址对应的索引信息，其中，所述第一本地DNS服务器为所述第一应用平台提供服务。In a possible design, the first information further includes index information corresponding to at least one application platform on which the first application is located, and information about a local DNS server corresponding to at least one application platform on which the first application is located. IP address; the session management function network element determines third information according to the first information, and sends the third information to the first user plane network element; the session management function network element according to the first application The index information corresponding to the platform, the at least one application platform where the first application is located, and the IP address of a local DNS server respectively corresponding to the at least one application platform where the first application is located determine the second information. Wherein, the third information includes the correspondence between the IP address of the local DNS server corresponding to the at least one application platform where the first application is located and the index information corresponding to the at least one application platform where the first application is located. The second information includes index information corresponding to the IP address of the first local DNS server, where the first local DNS server provides services for the first application platform.

在一种可能的设计中，还包括：所述会话管理功能网元向第一用户面网元发送第一指示信息；所述第一指示信息用于指示所述第一用户面网元在接收到来自于所述终端设备的第一请求且所述第一请求包括所述第一域名时，根据所述第二信息确定第二请求，并将所述第二请求发送至第一DNS服务器。In a possible design, the method further includes: the session management function network element sends first indication information to the first user plane network element; the first indication information is used to indicate that the first user plane network element is receiving When the first request comes from the terminal device and the first request includes the first domain name, a second request is determined according to the second information, and the second request is sent to the first DNS server.

采用上述设计可以使第一用户面网元根据第二信息确定第二请求。With the above design, the first user plane network element can determine the second request according to the second information.

在一种可能的设计中，还包括：所述会话管理功能网元接收来自于所述第一用户面网元的第四信息，所述会话管理功能网元基于所述第四信息为所述终端设备的PDU会话选择本地PDU会话锚点以及选择上行分类器ULCL或分支点BP。所述第四信息包括所述第一应用所在的第二应用平台对应的DNAI、所述第一应用所在的第二应用平台对应的IP地址、所述第一IP地址中的至少一种；所述第一IP地址为部署在所述第二应用平台上的所述第一应用的服务器的IP地址。In a possible design, the method further includes: the session management function network element receiving fourth information from the first user plane network element, and the session management function network element is the The PDU session of the terminal device selects the local PDU session anchor point and the uplink classifier ULCL or branch point BP. The fourth information includes at least one of DNAI corresponding to the second application platform where the first application is located, an IP address corresponding to the second application platform where the first application is located, and the first IP address; The first IP address is the IP address of the server of the first application deployed on the second application platform.

采用上述设计可以使会话管理功能网元根据第四信息选择本地PDU会话锚点，进一步地，为该PDU会话选择ULCL或BP，实现本地分流，优化业务访问的路径，提高通信效率。With the above design, the session management function network element can select the local PDU session anchor point according to the fourth information, and further, select ULCL or BP for the PDU session to achieve local offloading, optimize the service access path, and improve communication efficiency.

在一种可能的设计中，所述方法还包括：所述会话管理功能网元根据所述第一信息和更新后的所述终端设备的位置信息，在所述至少一个应用平台中确定第三应用平台；所述会话管理功能网元向所述第一用户面网元发送所述第一域名和更新后的第二信息，所述更新后的第二信息与所述第三应用平台对应；所述会话管理功能网元接收来自于所述第一用户面网元的通知消息，所述通知消息用于指示所述会话管理功能网元向所述终端设备发送非接入层NAS消息，所述NAS消息包括所述第一域名。In a possible design, the method further includes: the session management function network element determines, in the at least one application platform, the third information based on the first information and the updated location information of the terminal device. Application platform; the session management function network element sends the first domain name and updated second information to the first user plane network element, where the updated second information corresponds to the third application platform; The session management function network element receives a notification message from the first user plane network element, where the notification message is used to instruct the session management function network element to send a non-access stratum NAS message to the terminal device, so The NAS message includes the first domain name.

采用上述设计可以实现当终端设备的位置发生变化时，会话管理功能网元将更新后的第二信息发送至第一用户面网元，以使第一用户面网元可以根据更新后的第二信息判断是否需要通过会话管理功能网元通知终端设备发起DNS查询。The above design can realize that when the location of the terminal device changes, the session management function network element sends the updated second information to the first user plane network element, so that the first user plane network element can be based on the updated second information The information determines whether it is necessary to notify the terminal device to initiate a DNS query through the session management function network element.

第二方面，本申请实施例提供一种发现应用的方法，该方法包括：第一用户面网元接收来自于会话管理功能网元的第一域名和第二信息，所述第一用户面网元接收来自于所述终端设备的第一请求，所述第一请求包括所述第一域名；所述第一用户面网元根据所述第二信息确定第二请求，并向第一DNS服务器发送所述第二请求。其中，所述第二信息由会话管理功能网元至少根据终端设备的位置信息所确定，所述终端设备的位置信息指示所述终端设备处于第一位置，所述第二请求用于在所述终端设备位于所述第一位置时获取所述第一域名对应的第一IP地址。In a second aspect, an embodiment of the present application provides a method for discovering applications. The method includes: a first user plane network element receives a first domain name and second information from a session management function network element, and the first user plane network element The element receives a first request from the terminal device, the first request includes the first domain name; the first user plane network element determines a second request according to the second information, and sends it to the first DNS server Send the second request. Wherein, the second information is determined by the session management function network element at least according to the location information of the terminal device, the location information of the terminal device indicates that the terminal device is in the first position, and the second request is used to The terminal device obtains the first IP address corresponding to the first domain name when the terminal device is located at the first location.

采用上述方法，第一用户面网元接收来自于会话管理功能网元的第二信息，当第一用户面网元接收到来自于终端设备的第一请求，且第一请求包括第一域名时，第一用户面网元根据第二信息确定第二请求，可以实现当终端设备在终端设备的位置信息所指示的位置请求访问第一域名时，能够就近访问本地业务，可以实现访问业务的时延较短，进而可以保证较高通信效率。Using the above method, the first user plane network element receives the second information from the session management function network element, and when the first user plane network element receives the first request from the terminal device, and the first request includes the first domain name , The first user plane network element determines the second request according to the second information, so that when the terminal device requests access to the first domain name at the location indicated by the location information of the terminal device, it can access the local service nearby, and the service can be accessed. The delay is shorter, and higher communication efficiency can be ensured.

在一种可能的设计中，所述第二信息包括第一应用平台对应的DNAI，所述第一应用所在的至少一个应用平台包括所述第一应用平台。In a possible design, the second information includes a DNAI corresponding to a first application platform, and at least one application platform on which the first application is located includes the first application platform.

在一种可能的设计中，所述第二信息包括第一应用平台对应的IP地址，所述第一应用所在的至少一个应用平台包括所述第一应用平台。In a possible design, the second information includes an IP address corresponding to a first application platform, and at least one application platform on which the first application is located includes the first application platform.

在一种可能的设计中，所述第二信息包括第一本地DNS服务器的IP地址，其中，所述第一本地DNS服务器为第一应用平台提供服务，所述第一应用所在的至少一个应用平台包括所述第一应用平台。In a possible design, the second information includes the IP address of the first local DNS server, where the first local DNS server provides services for the first application platform, and at least one application where the first application is located The platform includes the first application platform.

在一种可能的设计中，所述第二信息包括第一应用平台对应的DNAI对应的索引信息，所述第一应用所在的至少一个应用平台包括所述第一应用平台；所述第一用户面网元接收来自于所述会话管理功能网元的第三信息；所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的DNAI与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系。In a possible design, the second information includes index information corresponding to DNAI corresponding to the first application platform, and at least one application platform on which the first application is located includes the first application platform; the first user The plane network element receives third information from the session management function network element; the third information includes the DNAI corresponding to the at least one application platform where the first application is located and at least one application where the first application is located. Correspondence of index information corresponding to each platform.

在一种可能的设计中，所述第二信息包括第一应用平台对应的IP地址对应的索引信息，所述第一应用所在的至少一个应用平台包括所述第一应用平台；所述第一用户面网元接收来自于所述会话管理功能网元的第三信息；所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的IP地址与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系。In a possible design, the second information includes index information corresponding to the IP address corresponding to the first application platform, and at least one application platform on which the first application is located includes the first application platform; The user plane network element receives the third information from the session management function network element; the third information includes the respective IP addresses of at least one application platform where the first application is located and at least the address where the first application is located. Correspondence of index information corresponding to one application platform.

在一种可能的设计中，所述第二信息包括第一本地DNS服务器的IP地址对应的索引信息，其中，所述第一本地DNS服务器为第一应用平台提供服务，所述第一应用所在的至少一个应用平台包括所述第一应用平台；所述第一用户面网元接收来自于所述会话管理功能网元的第三信息；所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系。In a possible design, the second information includes index information corresponding to the IP address of the first local DNS server, where the first local DNS server provides services for the first application platform, and the first application is located At least one application platform of the application platform includes the first application platform; the first user plane network element receives third information from the session management function network element; the third information includes at least the first application The corresponding relationship between the IP address of the local DNS server corresponding to one application platform and the index information respectively corresponding to the at least one application platform where the first application is located.

在一种可能的设计中，还包括：所述第一用户面网元接收来自于所述会话管理功能网元的第一指示信息；所述第一指示信息用于指示所述第一用户面网元在接收到来自于所述终端设备的第一请求且所述第一请求包括所述第一域名时，根据所述第二信息确定第二请求，并将所述第二请求发送至第一DNS服务器。In a possible design, the method further includes: the first user plane network element receives first indication information from the session management function network element; the first indication information is used to indicate the first user plane When the network element receives the first request from the terminal device and the first request includes the first domain name, it determines a second request according to the second information, and sends the second request to the first request. A DNS server.

在一种可能的设计中，所述第一用户面网元将所述第一应用平台对应的DNAI添加至所述第一请求，获得第二请求，并将所述第二请求发送至所述第一DNS服务器，所述第一DNS服务器为集中DNS服务器。In a possible design, the first user plane network element adds the DNAI corresponding to the first application platform to the first request, obtains a second request, and sends the second request to the The first DNS server, the first DNS server is a centralized DNS server.

在一种可能的设计中，所述第一用户面网元将所述第一应用平台对应的IP地址添加至所述第一请求，获得第二请求，并将所述第二请求发送至所述第一DNS服务器，所述第一DNS服务器为集中DNS服务器。In a possible design, the first user plane network element adds the IP address corresponding to the first application platform to the first request, obtains a second request, and sends the second request to all In the first DNS server, the first DNS server is a centralized DNS server.

在一种可能的设计中，所述第一用户面网元将所述第一请求的目标地址修改为所述第一本地DNS服务器的IP地址，获得第二请求，并将所述第二请求发送至所述第一DNS服务器，所述第一DNS服务器为所述第一本地DNS服务器。In a possible design, the first user plane network element modifies the target address of the first request to the IP address of the first local DNS server, obtains the second request, and transfers the second request to the IP address of the first local DNS server. Sent to the first DNS server, where the first DNS server is the first local DNS server.

在一种可能的设计中，还包括：所述第一用户面网元向所述会话管理功能网元发送第四信息，所述第四信息包括所述第一应用所在的第二应用平台对应的DNAI、所述第一应用所在的第二应用平台对应的IP地址、所述第一IP地址中的至少一种；其中，所述第一IP地址为部署在所述第二应用平台上的所述第一应用的服务器的IP地址。In a possible design, the method further includes: the first user plane network element sends fourth information to the session management function network element, and the fourth information includes the corresponding information of the second application platform where the first application is located. At least one of the DNAI, the IP address corresponding to the second application platform where the first application is located, and the first IP address; wherein the first IP address is deployed on the second application platform The IP address of the server of the first application.

在一种可能的设计中，还包括：所述第一用户面网元接收来自于所述会话管理功能网元的所述第一域名和更新后的第二信息，所述更新后的第二信息与所述第三应用平台对应；所述第一用户面网元向所述会话管理功能网元发送通知消息，所述通知消息用于指示所述会话管理功能网元向所述终端设备发送NAS消息，所述NAS消息包括所述第一域名。In a possible design, the method further includes: the first user plane network element receiving the first domain name and updated second information from the session management function network element, the updated second The information corresponds to the third application platform; the first user plane network element sends a notification message to the session management function network element, and the notification message is used to instruct the session management function network element to send to the terminal device NAS message, where the NAS message includes the first domain name.

在一种可能的设计中，还包括：在所述第一用户面网元向所述会话管理功能网元发送所述通知消息之前，所述第一用户面网元确定所述第一域名对应的DNS缓存记录的存留时间TTL未超过预设时长。In a possible design, the method further includes: before the first user plane network element sends the notification message to the session management function network element, the first user plane network element determines that the first domain name corresponds to The retention time TTL of the DNS cache records in the DNS does not exceed the preset duration.

采用上述设计可以实现当终端设备的位置发生变化时，在第一用户面网元接收到更新后的第二信息后，第一用户面网元根据更新后的第二信息确定需要通过会话管理功能网元通知终端设备发起DNS查询。With the above design, when the location of the terminal device changes, after the first user plane network element receives the updated second information, the first user plane network element determines that it needs to pass the session management function according to the updated second information. The network element informs the terminal device to initiate a DNS query.

第三方面，本申请提供一种通信装置，该装置可以是会话管理功能网元，也可以是会话管理功能网元内的芯片。该装置可以包括处理单元、发送单元和接收单元。应理解的是，这里发送单元和接收单元还可以为收发单元。当该装置是会话管理功能网元时，该处理单元可以是处理器，该发送单元和接收单元可以是收发器；该会话管理功能网元还可以包括存储单元，该存储单元可以是存储器；该存储单元用于存储指令，该处理单元执行该存储单元所存储的指令，以使该会话管理功能网元执行第一方面或第一方面任意一种可能的设计中的方法。当该装置是会话管理功能网元内的芯片时，该处理单元可以是处理器，该发送单元和接收单元可以是输入/输出接口、管脚或电路等；该处理单元执行存储单元所存储的指令，以使该芯片执行第一方面或第一方面任意一种可能的设计中的方法。该存储单元用于存储指令，该存储单元可以是该芯片内的存储单元(例如，寄存器、缓存等)，也可以是该会话管理功能网元内的位于该芯片外部的存储单元(例如，只读存储器、随机存取存储器等)。In the third aspect, this application provides a communication device, which may be a session management function network element or a chip in a session management function network element. The device may include a processing unit, a sending unit, and a receiving unit. It should be understood that the sending unit and the receiving unit here may also be a transceiving unit. When the device is a session management function network element, the processing unit may be a processor, the sending unit and the receiving unit may be transceivers; the session management function network element may also include a storage unit, and the storage unit may be a memory; The storage unit is used to store instructions, and the processing unit executes the instructions stored in the storage unit, so that the session management function network element executes the first aspect or any one of the possible design methods in the first aspect. When the device is a chip in a session management function network element, the processing unit may be a processor, the sending unit and the receiving unit may be input/output interfaces, pins or circuits, etc.; the processing unit executes what is stored in the storage unit Instructions to make the chip execute the first aspect or any one of the possible design methods in the first aspect. The storage unit is used to store instructions. The storage unit can be a storage unit in the chip (for example, a register, a cache, etc.), or a storage unit outside the chip in the session management function network element (for example, only Read memory, random access memory, etc.).

第四方面，本申请提供一种通信装置，该装置可以是第一用户面网元，也可以是第一用户面网元内的芯片。该装置可以包括处理单元、发送单元和接收单元。应理解的是，这里发送单元和接收单元还可以为收发单元。当该装置是第一用户面网元时，该处理单元可以是处理器，该发送单元和接收单元可以是收发器；该第一用户面网元还可以包括存储单元，该存储单元可以是存储器；该存储单元用于存储指令，该处理单元执行该存储单元所存储的指令，以使该第一用户面网元执行第二方面或第二方面任意一种可能的设计中的方法。当该装置是第一用户面网元内的芯片时，该处理单元可以是处理器，该发送单元和接收单元可以是输入/输出接口、管脚或电路等；该处理单元执行存储单元所存储的指令，以使该芯片执行第二方面或第二方面任意一种可能的设计中的方法。该存储单元用于存储指令，该存储单元可以是该芯片内的存储单元(例如，寄存器、缓存等)，也可以是该第一用户面网元内的位于该芯片外部的存储单元(例如，只读存储器、随机存取存储器等)。In a fourth aspect, the present application provides a communication device, which may be a first user plane network element or a chip in the first user plane network element. The device may include a processing unit, a sending unit, and a receiving unit. It should be understood that the sending unit and the receiving unit here may also be a transceiving unit. When the device is the first user plane network element, the processing unit may be a processor, the sending unit and the receiving unit may be transceivers; the first user plane network element may also include a storage unit, and the storage unit may be a memory The storage unit is used to store instructions, and the processing unit executes the instructions stored in the storage unit, so that the first user plane network element executes the second aspect or any one of the possible design methods in the second aspect. When the device is a chip in the first user plane network element, the processing unit may be a processor, the sending unit and the receiving unit may be input/output interfaces, pins or circuits, etc.; the processing unit executes what is stored in the storage unit , So that the chip executes the second aspect or any one of the possible design methods in the second aspect. The storage unit is used to store instructions. The storage unit can be a storage unit (for example, a register, a cache, etc.) in the chip, or a storage unit outside the chip in the first user plane network element (for example, Read only memory, random access memory, etc.).

第五方面，本申请还提供一种可读存储介质，该可读存储介质存储指令，当指令被执行时，使上述第一方面或第二方面的方法被实现。In a fifth aspect, the present application also provides a readable storage medium that stores instructions, and when the instructions are executed, the method of the first aspect or the second aspect described above is implemented.

第六方面，本申请还提供一种计算机程序代码，该计算机程序代码在计算机上运行时，使得计算机执行上述第一方面或第二方面的方法。In a sixth aspect, the present application also provides computer program code, which when running on a computer, causes the computer to execute the method of the first aspect or the second aspect.

第七方面，本申请还提供一种包含程序的计算机程序产品，当其在计算机上运行时，使得计算机执行上述第一方面或第二方面的方法。In a seventh aspect, the present application also provides a computer program product containing a program, which when running on a computer, causes the computer to execute the method of the first aspect or the second aspect.

第八方面，本申请还提供一种通信装置，包括处理器和存储器；存储器用于存储计算机执行指令；处理器用于执行存储器所存储的计算机执行指令，以使通信装置执行上述第一方面的方法。In an eighth aspect, the present application also provides a communication device including a processor and a memory; the memory is used to store computer execution instructions; the processor is used to execute the computer execution instructions stored in the memory, so that the communication device executes the method of the first aspect above .

第九方面，本申请还提供一种通信装置，包括处理器和接口电路；接口电路，用于接收代码指令并传输至处理器；处理器运行代码指令以执行上述第一方面或第二方面的方法。In a ninth aspect, the present application also provides a communication device including a processor and an interface circuit; the interface circuit is used to receive code instructions and transmit them to the processor; the processor runs the code instructions to execute the above-mentioned first aspect or second aspect method.

第十方面，本申请还提供一种通信***，通信***包括会话管理功能网元和第一用户面网元，会话管理功能网元执行上述第一方面的方法，第一用户面网元执行上述第二方面的方法。In a tenth aspect, the present application also provides a communication system. The communication system includes a session management function network element and a first user plane network element. The session management function network element executes the method of the first aspect, and the first user plane network element executes the foregoing The second aspect of the method.

附图说明Description of the drawings

图1为本申请中5G***架构示意图之一；Figure 1 is one of the schematic diagrams of the 5G system architecture in this application;

图2为本申请中5G***架构示意图之二；Figure 2 is the second schematic diagram of the 5G system architecture in this application;

图3为本申请中域名访问示意图；Figure 3 is a schematic diagram of domain name access in the application;

图4为本申请中PDU会话建立过程的示意图；Figure 4 is a schematic diagram of the PDU session establishment process in the application;

图5为本申请中在PDU会话初始建立完成之后终端设备请求域名对应的IP地址的示意图；FIG. 5 is a schematic diagram of the terminal device requesting the IP address corresponding to the domain name after the initial establishment of the PDU session in this application;

图6为本申请中发现应用的方法流程图之一；Figure 6 is one of the flowcharts of the method for discovering applications in this application;

图7为本申请中发现应用的方法流程图之二；Figure 7 is the second flow chart of the method for discovering applications in this application;

图8为本申请中UE请求域名对应的IP地址的具体流程图之一；Figure 8 is one of the specific flowcharts of the UE requesting the IP address corresponding to the domain name in this application;

图9为本申请中UE请求域名对应的IP地址的具体流程图之二；Figure 9 is the second specific flowchart of the UE requesting the IP address corresponding to the domain name in this application;

图10为本申请中UE请求域名对应的IP地址的具体流程图之三；Figure 10 is the third specific flowchart of the UE requesting the IP address corresponding to the domain name in this application;

图11为本申请中UE请求域名对应的IP地址的具体流程图之四；Figure 11 is the fourth specific flowchart of the UE requesting the IP address corresponding to the domain name in this application;

图12为本申请中UE请求域名对应的IP地址的具体流程图之五；Figure 12 is the fifth specific flowchart of the UE requesting the IP address corresponding to the domain name in this application;

图13为本申请中UE请求域名对应的IP地址的具体流程图之六；Figure 13 is the sixth specific flowchart of the UE requesting the IP address corresponding to the domain name in this application;

图14为本申请中UE请求域名对应的IP地址可能涉及的网元组成的网络架构的示意图；FIG. 14 is a schematic diagram of a network structure composed of network elements that may be involved in a UE requesting an IP address corresponding to a domain name in this application;

图15为本申请中SMF更新翻译表的示意图；Figure 15 is a schematic diagram of the SMF update translation table in this application;

图16为本申请中一种通信装置的结构示意图之一；FIG. 16 is one of the schematic structural diagrams of a communication device in this application;

图17为本申请中一种通信装置的结构示意图之二。FIG. 17 is the second structural diagram of a communication device in this application.

具体实施方式Detailed ways

下面将结合附图，对本申请实施例进行详细描述。The embodiments of the present application will be described in detail below in conjunction with the accompanying drawings.

本申请实施例主要应用于5G***架构，如图1和图2所示。图2为基于点对点接口的5G网络架构示意图。图1与图2的主要区别在于：图2中的各个网元之间的接口是点对点的接口，而不是服务化的接口。应理解的是，以下如图6至图12所示的实施例均可应用于但不限于如图1和图2所示的网络架构。The embodiments of the present application are mainly applied to the 5G system architecture, as shown in FIG. 1 and FIG. 2. Figure 2 is a schematic diagram of a 5G network architecture based on a point-to-point interface. The main difference between Fig. 1 and Fig. 2 is that the interfaces between the various network elements in Fig. 2 are point-to-point interfaces rather than service-oriented interfaces. It should be understood that the following embodiments shown in FIG. 6 to FIG. 12 can be applied to but not limited to the network architecture shown in FIG. 1 and FIG. 2.

5G网络架构中可包括三部分，分别是终端设备部分、数据网络(data network，DN)和运营商网络部分。The 5G network architecture can include three parts, namely the terminal equipment part, the data network (DN) and the operator network part.

其中，终端设备也可以称为终端(terminal)、用户设备(user equipment，UE)、移动台(mobile station，MS)、移动终端(mobile terminal，MT)等。终端设备可以是手机(mobile phone)、平板电脑(Pad)、带无线收发功能的电脑、虚拟现实(Virtual Reality，VR)终端设备、增强现实(Augmented Reality，AR)终端设备、工业控制(industrial control)中的无线终端、无人驾驶(self-driving)中的无线终端、远程手术(remote medical surgery)中的无线终端、智能电网(smart grid)中的无线终端、运输安全(transportation safety)中的无线终端、智慧城市(smart city)中的无线终端、智慧家庭(smart home)中的无线终端等。Among them, the terminal device may also be referred to as a terminal (terminal), user equipment (UE), mobile station (mobile station, MS), mobile terminal (mobile terminal, MT), and so on. Terminal devices can be mobile phones, tablets, computers with wireless transceiver functions, virtual reality (VR) terminal devices, augmented reality (Augmented Reality, AR) terminal devices, industrial control (industrial control) ), wireless terminals in self-driving (self-driving), wireless terminals in remote surgery (remote medical surgery), wireless terminals in smart grid (smart grid), transportation safety (transportation safety) Wireless terminal, wireless terminal in smart city, wireless terminal in smart home, etc.

运营商网络可以包括以下网元中的一个或多个：鉴权服务器功能(authentication server function，AUSF)网元、网络开放功能(network exposure function，NEF)网元、策略控制功能(policy control function，PCF)网元、统一数据管理(unified data management，UDM)网元、统一数据库(unified data repository，UDR)、网络存储功能(network repository function，NRF)网元、应用功能(application function，AF)网元、接入与移动性管理功能(access and mobility management function，AMF)网元、会话管理功能(session management function， SMF)网元、无线接入网(radio access network，RAN)以及用户面功能(user plane function，UPF)网元等。上述运营商网络中，除无线接入网部分之外的部分可以称为核心网络部分。The operator’s network may include one or more of the following network elements: authentication server function (AUSF) network element, network exposure function (NEF) network element, policy control function (policy control function, PCF) network element, unified data management (UDM) network element, unified data repository (UDR), network storage function (network repository function, NRF) network element, application function (AF) network Element, access and mobility management function (AMF) network element, session management function (SMF) network element, radio access network (RAN), and user plane function ( user plane function, UPF) network elements, etc. In the above-mentioned operator's network, the part other than the radio access network part may be referred to as the core network part.

RAN用于实现无线接入有关的功能；RAN is used to implement functions related to wireless access;

AMF网元用于实现移动性管理功能，负责用户的移动性管理，包括移动状态管理，分配用户临时身份标识，认证和授权用户；The AMF network element is used to implement mobility management functions, and is responsible for user mobility management, including mobility status management, assigning user temporary identities, and authenticating and authorizing users;

SMF网元用于实现会话管理功能，负责UPF网元选择，UPF网元重选，IP地址分配，负责承载的建立、修改和释放，服务质量(quality of service，QoS)控制；SMF network elements are used to implement session management functions, are responsible for UPF network element selection, UPF network element reselection, IP address allocation, bearer establishment, modification and release, and quality of service (QoS) control;

PCF网元包含策略控制决策和基于流计费控制的功能，包含用户签约数据管理功能，策略控制功能，计费策略控制功能，QoS控制等；PCF network elements include policy control decision-making and flow-based charging control functions, including user subscription data management functions, policy control functions, charging policy control functions, QoS control, etc.;

UDM网元负责管理签约数据，当签约数据修改的时候，负责通知相应的网元。The UDM network element is responsible for managing the contracted data, and when the contracted data is modified, it is responsible for notifying the corresponding network element.

UDR用于存储和检索签约数据、策略数据和公共架构数据等，供UDM网元、PCF网元和NEF网元获取相关数据。UDR能够针对不同类型的数据(如签约数据、策略数据)具有不同的数据接入鉴权机制，以保证数据接入的安全性；UDR对于非法的服务化操作或者数据接入请求能够返回携带合适原因值的失败响应。UDR is used to store and retrieve contract data, policy data, and public architecture data, etc., for UDM network elements, PCF network elements, and NEF network elements to obtain relevant data. UDR can have different data access authentication mechanisms for different types of data (such as contract data, policy data) to ensure the security of data access; UDR can return and carry appropriate data for illegal servicing operations or data access requests The failure response for the reason value.

AF网元用于向UE提供某种应用层服务，AF在向UE提供服务时，对QoS和计费(charging)策略有要求，且需要通知网络。同时，AF也需要核心网反馈的应用相关的信息。The AF network element is used to provide a certain application layer service to the UE. When the AF provides the service to the UE, it has requirements for QoS and charging strategies and needs to notify the network. At the same time, AF also needs application-related information fed back from the core network.

NEF网元主要支持网络能力开放功能，对外开放网络能力和服务；3GPP网络功能(network function，NF)通过NEF向其他NF发布功能和事件。NF开放的能力和事件可以安全地开放给第三方应用。NEF使用UDR的标准化接口(Nudr)将结构化数据进行存储或检索，将AF的交换信息与内部网络功能的交换信息进行翻译。例如，它将在AF服务识别符(AF-Service-Identifier)和内部5G核心信息(如数据网络名称(data network name，DNN)，单网络切片选择辅助信息(single network slice selection assistance information，S-NSSAI))之间进行转换。NEF network elements mainly support network capability opening functions, opening network capabilities and services to the outside world; 3GPP network functions (network functions, NF) publish functions and events to other NFs through NEF. The capabilities and events opened by NF can be safely opened to third-party applications. NEF uses UDR's standardized interface (Nudr) to store or retrieve structured data, and translate AF exchange information with internal network function exchange information. For example, it will use the AF service identifier (AF-Service-Identifier) and internal 5G core information (such as data network name (DNN), single network slice selection assistance information, S- NSSAI)).

UPF(User Plane Function)网元可以支持以下全部或者部分功能：将协议数据单元(protocol data unit，PDU)会话与数据网络互连；分组路由和转发(例如，支持对流量进行上行分类器(uplink classifier，ULCL)后转发到数据网络，支持分支点(branching point，BP)以支持多归属(multi-homed)PDU会话)；数据包检测。UPF (User Plane Function) network elements can support all or part of the following functions: interconnecting protocol data unit (PDU) sessions with data networks; packet routing and forwarding (for example, supporting uplink classifiers for traffic) classifier, ULCL) and then forwarded to the data network, support branch point (branching point, BP) to support multi-homed (multi-homed) PDU session); data packet inspection.

此外，本申请实施例中涉及的网元还包括：DNS代理(proxy)，地址解析功能网元(address resolution function，ARF)和及DNS服务器(server)。In addition, the network elements involved in the embodiments of the present application also include: DNS proxy (proxy), address resolution function (ARF) and DNS server (server).

DNS proxy是指在防火墙上启动DNS代理功能，这样在局域网内部没有DNS服务器时，局域网内部客户端可以通过防火墙连接到外部DNS服务器，通过外部DNS服务器进行正确的DNS解析实现访问互联网(internet)。DNS proxy refers to enabling the DNS proxy function on the firewall, so that when there is no DNS server inside the LAN, the client inside the LAN can connect to the external DNS server through the firewall, and access the Internet (internet) through the correct DNS resolution of the external DNS server.

DNS proxy的工作机制具体如下：DNS客户端将DNS请求报文发送给DNS proxy，此时该报文的目的地址为DNS proxy的IP地址。DNS proxy接收到该报文后，将该报文中的目的地址替换为DNS服务器的IP地址，然后根据已配置的DNS服务器的地址将该报文转发给DNS服务器。若在DNS proxy上配置了多个DNS服务器的地址，则DNS proxy先向第一个DNS服务器发送该报文，若第一个DNS服务器没有响应，则DNS客户端等待超时后会重新发送DNS请求报文，DNS proxy接收到重新发送的DNS请求报文后向第二个DNS服务器转发，以此类推，直到有DNS服务器发送响应报文为止。The working mechanism of DNS proxy is as follows: The DNS client sends a DNS request message to the DNS proxy. At this time, the destination address of the message is the IP address of the DNS proxy. After the DNS proxy receives the message, it replaces the destination address in the message with the IP address of the DNS server, and then forwards the message to the DNS server according to the configured DNS server address. If multiple DNS server addresses are configured on the DNS proxy, the DNS proxy first sends the message to the first DNS server. If the first DNS server does not respond, the DNS client will resend the DNS request after waiting for the timeout After the DNS proxy receives the resent DNS request packet, it forwards it to the second DNS server, and so on, until a DNS server sends a response packet.

DNS服务器负责将域名解析为IP地址，例如客户端向DNS服务器发送域名查询请求， DNS服务器返回该域名对应的IP地址，进而终端设备可以通过该IP地址访问该域名。The DNS server is responsible for resolving the domain name into an IP address. For example, the client sends a domain name query request to the DNS server, and the DNS server returns the IP address corresponding to the domain name, and the terminal device can access the domain name through the IP address.

地址解析功能网元的功能可以同时支持DNS proxy和DNS服务器的功能，也可以只支持DNS proxy的功能或者DNS服务器的功能。The function of the network element with the address resolution function can support the functions of DNS proxy and DNS server at the same time, or only support the function of DNS proxy or the function of DNS server.

应理解的是，以上各个网元的功能介绍不作为本申请的限定。It should be understood that the above description of the functions of each network element is not a limitation of this application.

以下简要介绍现有域名访问的过程：The following briefly introduces the process of accessing existing domain names:

如图3所示，目前，域名访问的过程如下：以终端设备访问域名A(例如，www.qq.com)为例，当终端设备访问该域名A时，查询该终端设备的缓存中是否存在该域名A对应的IP地址，如果存在，则终端设备可以直接获取该IP地址，通过该IP地址访问该域名A；如果不存在，则终端设备可以向DNS服务器发送域名解析请求，该域名解析请求携带该域名A，由DNS服务器返回该域名A对应的IP地址，终端设备可以通过该IP地址访问该域名A。As shown in Figure 3, the current domain name access process is as follows: Take the terminal device accessing domain name A (for example, www.qq.com) as an example, when the terminal device accesses the domain name A, query whether the terminal device’s cache exists If the IP address corresponding to the domain name A exists, the terminal device can directly obtain the IP address and access the domain name A through the IP address; if it does not exist, the terminal device can send a domain name resolution request to the DNS server, and the domain name resolution request Carrying the domain name A, the DNS server returns the IP address corresponding to the domain name A, and the terminal device can access the domain name A through the IP address.

此外，终端设备在获得域名A对应的IP地址后，生成并缓存一条DNS缓存记录。该DNS缓存记录用于表示域名A与IP地址的对应关系。终端设备还针对DNS缓存记录维护相应的存留时间(time to live，TTL)。DNS缓存记录的TTL是指该DNS缓存记录在终端设备的缓存中的保留的时间。这样，当在DNS缓存记录的TTL内，终端设备需要再次访问该DNS缓存记录中的域名A时，则终端设备可以直接根据该DNS缓存记录，获取域名A对应的IP地址。当超过该DNS缓存记录的TTL后，则终端设备需要通过上述过程，通过DNS服务器获得域名A对应的IP地址。In addition, after obtaining the IP address corresponding to domain name A, the terminal device generates and caches a DNS cache record. The DNS cache record is used to indicate the correspondence between the domain name A and the IP address. The terminal device also maintains a corresponding time to live (TTL) for the DNS cache record. The TTL of the DNS cache record refers to the retention time of the DNS cache record in the cache of the terminal device. In this way, when the terminal device needs to access the domain name A in the DNS cache record again within the TTL of the DNS cache record, the terminal device can directly obtain the IP address corresponding to the domain name A according to the DNS cache record. When the TTL of the DNS cache record is exceeded, the terminal device needs to obtain the IP address corresponding to domain name A through the DNS server through the above process.

如图4所示，在PDU会话初始建立过程中，为了选择最佳的锚点UPF，核心网会参考终端设备的位置来选择PDU会话锚点(PDU session achor，PSA)，但是由于终端设备具有移动性，远端PSA(即在PDU会话初始建立过程中选择的PSA)的位置不能代表终端设备当前所在的物理位置。在图4的基础上，图5为在PDU会话初始建立完成之后终端设备请求域名对应的IP地址的示意图。如图5所示，假设在PDU会话初始建立过程中核心网为终端设备分配的地址为IP-3，当终端设备通过远端PSA请求DNS服务器查询域名A时，远端PSA将终端设备的DNS查询请求发送至DNS服务器。其中，域名A对应的应用服务器可以有多个，分别部署在不同的位置。例如，域名A对应的应用服务器部署在两个不同的MEC平台上，即MEC平台-1和MEC平台-2。两个应用服务器的IP地址分别为IP-3A和IP-1。其中，IP地址为IP-3A的应用服务器部署在MEC平台-1上，IP地址为IP-1的应用服务器部署在MEC平台-2上，MEC平台-1的部署位置与远端PSA之间距离较近，与终端设备的当前位置之间的距离较远，而MEC平台-1的部署位置与远端PSA之间距离较远，与终端设备的当前位置之间的距离较近。由于DNS服务器不感知终端设备当前的位置，DNS服务从远端PSA接收来自终端设备的DNS查询请求之后，按照地址亲和性，并根据请求的域名A返回跟远端PSA之间的距离较近的应用服务器的IP地址，因此，DNS服务器返回MEC平台-1上部署的应用服务器的地址(如图5中的IP-3A)，这样终端设备就无法获取到MEC平台-2上部署的应用服务器的IP地址，导致终端设备无法通过MEC平台-2上部署的应用服务器就近访问业务。并且，由于终端设备通过远端应用服务器访问业务，增大了终端设备访问业务的时延，降低了通信效率。As shown in Figure 4, during the initial establishment of the PDU session, in order to select the best anchor UPF, the core network will refer to the location of the terminal device to select the PDU session anchor (PSA), but because the terminal device has For mobility, the location of the remote PSA (that is, the PSA selected during the initial establishment of the PDU session) cannot represent the current physical location of the terminal device. Based on FIG. 4, FIG. 5 is a schematic diagram of a terminal device requesting an IP address corresponding to a domain name after the initial establishment of a PDU session is completed. As shown in Figure 5, assuming that the core network allocates IP-3 to the terminal device during the initial establishment of the PDU session, when the terminal device requests the DNS server to query the domain name A through the remote PSA, the remote PSA will change the DNS of the terminal device The query request is sent to the DNS server. Among them, there may be multiple application servers corresponding to domain name A, which are respectively deployed in different locations. For example, the application server corresponding to domain name A is deployed on two different MEC platforms, namely MEC platform-1 and MEC platform-2. The IP addresses of the two application servers are IP-3A and IP-1 respectively. Among them, the application server with IP address IP-3A is deployed on MEC platform-1, the application server with IP address IP-1 is deployed on MEC platform-2, and the distance between the deployment location of MEC platform-1 and the remote PSA Closer means a longer distance from the current position of the terminal device, while the deployment position of the MEC platform-1 is farther away from the remote PSA, and closer to the current position of the terminal device. Since the DNS server does not perceive the current location of the terminal device, the DNS service receives the DNS query request from the terminal device from the remote PSA, according to the address affinity, and returns according to the requested domain name A to be closer to the remote PSA Therefore, the DNS server returns the address of the application server deployed on the MEC platform-1 (IP-3A in Figure 5), so that the terminal device cannot obtain the application server deployed on the MEC platform-2 The IP address of the terminal device cannot access nearby services through the application server deployed on the MEC platform-2. In addition, since the terminal device accesses the service through the remote application server, the time delay for the terminal device to access the service is increased, and the communication efficiency is reduced.

应理解的是，本申请实施例还可以适用于面向未来的其他通信技术。本申请描述的网络架构以及业务场景是为了更加清楚的说明本申请的技术方案，并不构成对本申请提供的技术方案的限定，本领域普通技术人员可知，随着网络架构的演变和新业务场景的出现，本申请提供的技术方案对于类似的技术问题，同样适用。It should be understood that the embodiments of the present application may also be applicable to other future-oriented communication technologies. The network architecture and business scenarios described in this application are intended to explain the technical solutions of this application more clearly, and do not constitute a limitation on the technical solutions provided by this application. Those of ordinary skill in the art will know that with the evolution of the network architecture and new business scenarios The technical solutions provided in this application are equally applicable to similar technical problems.

以下对本申请实施例可能涉及的技术术语进行说明。The following describes the technical terms that may be involved in the embodiments of the present application.

终端设备的位置信息可以是指终端设备的跟踪区标识(tracking area identity，TAI)。The location information of the terminal device may refer to the tracking area identity (TAI) of the terminal device.

一个应用平台的位置信息可以用该应用平台对应的数据网络接入标识(DN Access Identifier，DNAI)或者该应用平台对应的IP地址来表示。The location information of an application platform can be represented by a data network access identifier (DN Access Identifier, DNAI) corresponding to the application platform or an IP address corresponding to the application platform.

其中，一个应用平台对应的IP地址是指网络中的网元设备访问该应用平台时，路由路径上所需的IP地址，或者，一个应用平台对应的IP地址是指网络中的网元设备与该应用平台进行通信时，通信路径上所需的IP地址。示例性地，一个应用平台对应的IP地址可以是访问该应用平台所需的公网IP地址，例如，该公网IP地址是该应用平台入口的公网IP地址空间里面的任一公网IP地址。示例性地，一个应用平台对应的IP地址可以是访问该应用平台所需的子网(subnet)IP地址或者完整IP地址(full IP address)，例如，该子网IP地址是UPF网元通过N6接口访问该应用平台时，执行网络地址转换(Network address translation，NAT)之后，指向该应用平台的subnet或者完整IP地址(subnets(or full IP addresses)after NAT)。Among them, the IP address corresponding to an application platform refers to the IP address required on the routing path when the network element device in the network accesses the application platform, or the IP address corresponding to an application platform refers to the network element device and the network element device in the network. The IP address required on the communication path when the application platform communicates. Exemplarily, the IP address corresponding to an application platform may be a public network IP address required to access the application platform, for example, the public network IP address is any public network IP in the public network IP address space of the entrance of the application platform address. Exemplarily, the IP address corresponding to an application platform may be a subnet (subnet) IP address or a full IP address (full IP address) required to access the application platform. For example, the subnet IP address is a UPF network element through N6 When an interface accesses the application platform, after performing network address translation (NAT), it points to the subnet or full IP address (subnets (or full IP addresses) after NAT) of the application platform.

本地(local)DNS服务器可以理解为位于本地数据中心的DNS服务器。本地DNS服务器距离UE的当前位置较近。本地DNS服务器主要负责对本地应用平台上或者MEC平台上部署的应用进行域名解析。当一个应用所在的至少一个应用平台包括本地应用平台或者MEC平台，那么服务该本地应用平台或者该MEC平台的DNS服务器可以称为本地DNS服务器，该本地DNS服务器对该本地应用平台上或者该MEC平台上部署的应用进行域名解析。本地DNS服务器可以由运营商部署或者第三方部署。A local DNS server can be understood as a DNS server located in a local data center. The local DNS server is closer to the current location of the UE. The local DNS server is mainly responsible for domain name resolution for applications deployed on the local application platform or on the MEC platform. When at least one application platform on which an application is located includes a local application platform or an MEC platform, the DNS server serving the local application platform or the MEC platform may be called a local DNS server, and the local DNS server is on the local application platform or the MEC The applications deployed on the platform perform domain name resolution. The local DNS server can be deployed by the operator or a third party.

集中(centralized)DNS服务器可以理解为位于集中式数据中心的DNS服务器或者位于远端管理平台且距离UE的当前位置较远的DNS服务器，集中DNS服务器还可以称为远端(remote)DNS服务器。集中DNS服务器可以由运营商部署。A centralized DNS server can be understood as a DNS server located in a centralized data center or a DNS server located on a remote management platform and far from the current location of the UE. The centralized DNS server can also be referred to as a remote DNS server. The centralized DNS server can be deployed by the operator.

本申请中的本地DNS服务器和集中DNS服务器分别支持的域名解析能力(即能够解析的域名类型)可以相同或者不同，本申请不做限定。The domain name resolution capabilities (that is, the types of domain names that can be resolved) supported by the local DNS server and the centralized DNS server in this application may be the same or different, and this application is not limited.

本申请实施例提供一种发现应用的方法，该方法用于实现DNS服务器将距离终端设备较近的应用服务器的IP地址返回给终端设备以使得终端设备能够就近访问本地业务。此外，采用本申请实施例提供的方法还可以实现在DNS服务器将距离终端设备较近的应用服务器的IP地址返回给终端设备之后，把业务流量选择性的路由到应用服务器所在的应用平台。如图6所示，该方法包括：The embodiment of the present application provides a method for discovering applications. The method is used to realize that the DNS server returns the IP address of the application server closer to the terminal device to the terminal device so that the terminal device can access local services nearby. In addition, using the method provided in the embodiments of the present application can also realize that after the DNS server returns the IP address of the application server close to the terminal device to the terminal device, the service traffic can be selectively routed to the application platform where the application server is located. As shown in Figure 6, the method includes:

步骤600：SMF网元获取第一信息。Step 600: The SMF network element obtains the first information.

其中，第一信息包括第一域名对应的第一应用的标识和第一应用所在的至少一个应用平台的位置信息；或者，第一信息包括第一域名和第一应用所在的至少一个应用平台的位置信息；或者，第一信息包括第一域名、第一域名对应的第一应用的标识和第一应用所在的至少一个应用平台的位置信息。Wherein, the first information includes the identification of the first application corresponding to the first domain name and the location information of at least one application platform where the first application is located; or, the first information includes the first domain name and the information of at least one application platform where the first application is located. Location information; or, the first information includes the first domain name, the identification of the first application corresponding to the first domain name, and the location information of at least one application platform on which the first application is located.

其中，SMF网元获取第一信息可以采用但不限于以下可能的设计：Among them, the SMF network element can adopt but not limited to the following possible designs to obtain the first information:

在一种可能的设计中，SMF网元可以本地配置第一信息。In a possible design, the SMF network element may locally configure the first information.

在另一种可能的设计中，SMF网元从其他网元获取第一信息。示例性地，AF网元将第一信息存储在UDR中。在终端设备发起PDU会话建立过程中，SMF网元调用PCF网元的服务化操作策略建立控制请求(Npcf_SMPolicy Control_Create Request)，请求从PCF 网元获取该PDU会话相关的策略信息。PCF网元调用UDR的服务化操作请求(Nudr_DM_Query)，从UDR获取该终端设备签约的应用相关的信息，其中包括第一信息。PCF网元将该第一信息生成策略计费控制规则(Policy and Charging Control rule,PCC rule)，PCC rule包括第一信息。通过服务化操作策略建立控制响应(Npcf_SMPolicyControl_Create Response)下发至SMF网元，SMF保存PCC rule。In another possible design, the SMF network element obtains the first information from other network elements. Exemplarily, the AF network element stores the first information in the UDR. When the terminal device initiates the establishment of a PDU session, the SMF network element calls the PCF network element's servicing operation policy establishment control request (Npcf_SMPolicy Control_Create Request), requesting to obtain the policy information related to the PDU session from the PCF network element. The PCF network element invokes the service operation request (Nudr_DM_Query) of the UDR, and obtains information related to the application subscribed by the terminal device from the UDR, including the first information. The PCF network element generates a policy and charging control rule (Policy and Charging Control rule, PCC rule) from the first information, and the PCC rule includes the first information. A control response (Npcf_SMPolicyControl_Create Response) is established through a service-based operation policy and sent to the SMF network element, and the SMF saves the PCC rule.

此外，可以理解为，第一信息中的一部分信息可以通过本地配置的方式存储在SMF网元中，第一信息中另一部分信息可以从其他网元获取。示例性地，SMF网元可以本地配置第一域名对应的第一应用的标识，SMF网元从PCF网元或者NEF网元获取第一应用所在的至少一个应用平台的位置信息，其中，PCF网元或者NEF网元存储了第一应用所在的至少一个应用平台的位置信息。In addition, it can be understood that part of the information in the first information may be stored in the SMF network element in a locally configured manner, and another part of the information in the first information may be obtained from other network elements. Exemplarily, the SMF network element may locally configure the identification of the first application corresponding to the first domain name, and the SMF network element obtains the location information of at least one application platform where the first application is located from the PCF network element or the NEF network element. The element or NEF network element stores the location information of at least one application platform where the first application is located.

应理解的是，第一应用所在的至少一个应用平台表明存在一个或多个应用平台，且在这些应用平台上部署了第一应用的服务器。这里的应用平台可以是指MEC平台，又可称为管理平台，或者应用管理平台。其中，第一应用所在的至少一个应用平台的位置信息又可描述为部署第一应用的服务器所在的至少一个应用平台的位置信息，本申请对此不作限定。示例性地，第一应用所在的至少一个应用平台的位置信息可以包括第一应用所在的至少一个应用平台分别对应的DNAI。It should be understood that at least one application platform where the first application is located indicates that one or more application platforms exist, and the server of the first application is deployed on these application platforms. The application platform here can refer to the MEC platform, also known as the management platform, or the application management platform. Wherein, the location information of the at least one application platform where the first application is located may be described as the location information of the at least one application platform where the server deploying the first application is located, which is not limited in this application. Exemplarily, the location information of the at least one application platform where the first application is located may include DNAIs respectively corresponding to the at least one application platform where the first application is located.

步骤610：SMF网元至少根据第一信息和终端设备的位置信息确定第二信息。第二信息用于获取第一域名对应的第一IP地址。Step 610: The SMF network element determines second information at least according to the first information and the location information of the terminal device. The second information is used to obtain the first IP address corresponding to the first domain name.

SMF网元获取终端设备的位置信息的一种实现方法是，SMF网元可以从其他网元获取终端设备的位置信息，例如，SMF网元可以从AMF网元获取终端设备的TAI。同时，SMF网元也可以向AMF网元请求终端设备的TAI。在终端设备的位置发生移动时，AMF网元可以向SMF网元提供终端设备当前的最新TAI，这样SMF网元可以基于终端设备当前的最新TAI确定终端设备的位置信息。An implementation method for the SMF network element to obtain the location information of the terminal device is that the SMF network element can obtain the location information of the terminal device from other network elements. For example, the SMF network element can obtain the TAI of the terminal device from the AMF network element. At the same time, the SMF network element can also request the TAI of the terminal device from the AMF network element. When the location of the terminal device moves, the AMF network element can provide the SMF network element with the current latest TAI of the terminal device, so that the SMF network element can determine the location information of the terminal device based on the current latest TAI of the terminal device.

在一种可能的设计中，SMF网元根据第一信息和终端设备的位置信息，在第一应用所在的至少一个应用平台中确定第一应用平台。In a possible design, the SMF network element determines the first application platform in at least one application platform where the first application is located according to the first information and the location information of the terminal device.

可以理解为，SMF网元可以根据第一信息和终端设备的位置信息从第一应用所在的至少一个应用平台中确定出距离终端设备较近的至少一个应用平台，即第一应用平台。其中，第一应用平台部署第一应用的服务器，且第一应用平台的数目可以为一个或多个。It can be understood that the SMF network element may determine, from at least one application platform where the first application is located, at least one application platform that is closer to the terminal device, that is, the first application platform, based on the first information and the location information of the terminal device. Wherein, the first application platform deploys the server of the first application, and the number of the first application platform may be one or more.

可以理解为，第一应用平台为终端设备在当前位置通过最优化路径访问第一应用的服务器时，第一应用的服务器所在的应用平台，换句话说，终端设备在向第一应用平台部署的第一应用的服务器发送数据报文时，该数据报文的路由路径为当前网络拓扑条件下的最优化路径。如果终端设备在当前位置通过最优化路径访问第一应用的服务器时，第一应用的服务器所在的应用平台的数目为多个，则第一应用平台的数目为多个。It can be understood that the first application platform is the application platform where the server of the first application is located when the terminal device accesses the server of the first application through the optimized path at the current location. In other words, the terminal device is deployed to the first application platform. When the server of the first application sends a data message, the routing path of the data message is the optimal path under the current network topology condition. If the terminal device accesses the server of the first application through the optimized path at the current location, the number of application platforms where the server of the first application is located is multiple, then the number of the first application platform is multiple.

应理解的是，SMF网元还可结合其他信息在第一应用所在的至少一个应用平台中确定第一应用平台，例如应用平台的负载信息，网络拓扑信息等，本申请对此不作限定。例如，SMF网元可以根据第一信息和终端设备的位置信息，在第一应用所在的至少一个应用平台中确定多个应用平台，SMF网元进一步结合多个应用平台分别对应的负载信息，确定其中负载最低的应用平台作为第一应用平台。It should be understood that the SMF network element may also determine the first application platform in at least one application platform where the first application is located in combination with other information, such as load information of the application platform, network topology information, etc., which is not limited in this application. For example, the SMF network element may determine multiple application platforms in at least one application platform where the first application is located according to the first information and the location information of the terminal device, and the SMF network element may further combine the load information corresponding to the multiple application platforms to determine The application platform with the lowest load is regarded as the first application platform.

示例性地，若第一应用所在的至少一个应用平台的位置信息为第一应用所在的至少一个应用平台分别对应的DNAI，SMF网元可以根据第一信息和终端设备的位置信息(例如， TAI)，从第一应用所在的至少一个应用平台中确定至少一个第一应用平台。具体地，终端设备的位置信息与第一应用所在的至少一个应用平台分别对应的DNAI之间可以存在映射关系或者对应关系。SMF网元根据终端设备的位置信息可以从第一应用所在的至少一个应用平台中确定至少一个第一应用平台。Exemplarily, if the location information of the at least one application platform where the first application is located is the DNAI corresponding to the at least one application platform where the first application is located, the SMF network element may use the first information and the location information of the terminal device (for example, TAI ), determining at least one first application platform from at least one application platform where the first application is located. Specifically, there may be a mapping relationship or a corresponding relationship between the location information of the terminal device and the DNAI respectively corresponding to the at least one application platform where the first application is located. The SMF network element may determine at least one first application platform from at least one application platform where the first application is located according to the location information of the terminal device.

以下基于第一信息包括的不同内容说明第二信息包括的具体内容。The following describes the specific content included in the second information based on the different content included in the first information.

第一种可能的形式：若第一应用所在的至少一个应用平台的位置信息包括第一应用所在的至少一个应用平台分别对应的DNAI，第二信息包括第一应用平台对应的DNAI。The first possible form: if the location information of the at least one application platform where the first application is located includes the DNAI corresponding to the at least one application platform where the first application is located, the second information includes the DNAI corresponding to the first application platform.

其中，SMF网元根据第一信息和终端设备的位置信息，在至少一个应用平台中确定第一应用平台。由于应用平台与应用平台对应的DNAI存在对应关系，因此，SMF网元确定第一应用平台后可以得到第一应用平台对应的DNAI，作为第二信息。应理解的是，第二信息可以用DNAI list表示。DNAI list包含至少一个DNAI。若第一应用平台的数目为多个，则DNAI list包括多个DNAI。Wherein, the SMF network element determines the first application platform in at least one application platform according to the first information and the location information of the terminal device. Since there is a corresponding relationship between the application platform and the DNAI corresponding to the application platform, the SMF network element can obtain the DNAI corresponding to the first application platform as the second information after determining the first application platform. It should be understood that the second information may be represented by a DNAI list. The DNAI list contains at least one DNAI. If the number of the first application platform is multiple, the DNAI list includes multiple DNAIs.

例如，第一信息包括第一域名FQDN-A，第一域名对应的第一应用的标识APP ID-1，第一应用所在的至少一个应用平台的位置信息包括DNAI1(对应MEC-1)和DNAI2(对应MEC-2)。SMF网元可以根据终端设备的位置信息和第一信息可以从DNAI1和DNAI2中确定DNAI1，并将DNAI1作为第二信息。For example, the first information includes the first domain name FQDN-A, the identification APP ID-1 of the first application corresponding to the first domain name, and the location information of at least one application platform where the first application is located includes DNAI1 (corresponding to MEC-1) and DNAI2 (Corresponding to MEC-2). The SMF network element may determine DNAI1 from DNAI1 and DNAI2 according to the location information of the terminal device and the first information, and use DNAI1 as the second information.

可以理解为，一个应用平台对应的DNAI可以代表该应用平台的位置信息，因此，当SMF网元将第一应用平台对应的DNAI作为第二信息发送给第一UPF网元，第一UPF网元可以将第一应用平台对应的DNAI添加到第一请求，得到第二请求，并向第一DNS服务器发送第二请求，以便第一DNS服务器根据第一应用平台的位置信息确定第一域名对应的第一IP地址。It can be understood that the DNAI corresponding to an application platform can represent the location information of the application platform. Therefore, when the SMF network element sends the DNAI corresponding to the first application platform as the second information to the first UPF network element, the first UPF network element The DNAI corresponding to the first application platform can be added to the first request to obtain the second request, and send the second request to the first DNS server, so that the first DNS server can determine the first domain name corresponding to the location information of the first application platform The first IP address.

第二种可能的形式：若第一信息还包括第一应用所在的至少一个应用平台分别对应的IP地址，第二信息包括第一应用平台对应的IP地址。A second possible form: if the first information further includes the IP addresses corresponding to at least one application platform where the first application is located, the second information includes the IP address corresponding to the first application platform.

其中，SMF网元根据第一信息和终端设备的位置信息，在至少一个应用平台中确定第一应用平台，进一步地，由于应用平台与应用平台对应的IP地址存在对应关系，因此，在确定第一应用平台后，SMF网元根据第一应用所在的至少一个应用平台分别对应的IP地址确定第一应用平台对应的IP地址，作为第二信息。Among them, the SMF network element determines the first application platform in at least one application platform according to the first information and the location information of the terminal device. Further, since the application platform has a corresponding relationship with the IP address corresponding to the application platform, the first application platform is determined. After an application platform, the SMF network element determines the IP address corresponding to the first application platform according to the IP addresses corresponding to the at least one application platform where the first application is located, as the second information.

例如，第一信息包括第一域名FQDN-A，第一域名对应的第一应用的标识APP ID-1，第一应用所在的至少一个应用平台的位置信息包括DNAI1(对应MEC-1)和DNAI2(对应MEC-2)，第一应用所在的至少一个应用平台分别对应的IP地址包括IP-1(对应DNAI1)和IP-2(对应DNAI2)。SMF网元可以根据终端设备的位置信息和第一信息可以从DNAI1和DNAI2中确定DNAI1，并根据DNAI1将IP-1作为第二信息。For example, the first information includes the first domain name FQDN-A, the identification APP ID-1 of the first application corresponding to the first domain name, and the location information of at least one application platform where the first application is located includes DNAI1 (corresponding to MEC-1) and DNAI2 (Corresponding to MEC-2), the IP addresses respectively corresponding to at least one application platform where the first application is located include IP-1 (corresponding to DNAI1) and IP-2 (corresponding to DNAI2). The SMF network element may determine DNAI1 from DNAI1 and DNAI2 according to the location information of the terminal device and the first information, and use IP-1 as the second information according to DNAI1.

根据现有对DNS消息的扩展机制(Extension Mechanisms for DNS，EDNS)，DNS查询消息可以添加EDNS客户端子网选项(ECS(EDNS Client Subnet)option)，该ECS option里面包含客户端的IP地址，以便DNS服务器基于该客户端的IP地址更好地确定客户端请求查询的域名对应的IP地址。由于终端设备的IP地址并不能体现出终端设备的位置，因此，在本申请中，SMF网元将第一应用平台对应的IP地址作为第二信息发送给第一UPF网元，第一UPF网元可以将该第二信息可以作为ECS option添加到第一请求，得到第二请求，并向第一DNS服务器发送第二请求，以便第一DNS服务器根据该ECS option更好地确定终端设备请求查询的第一域名对应的IP地址。因此，第二信息可以用ECS option list 表示。ECS option list包含至少一个ECS option。若第一应用平台的数目为多个，则ECS option list包括多个ECS option。每一个ECS option包括一个IP地址。其中，ECS option中包含的IP地址是应用平台对应IP地址。对该IP地址的描述可以参考前面的描述，重复之处不在赘述。According to the existing extension mechanisms for DNS messages (Extension Mechanisms for DNS, EDNS), DNS query messages can add an EDNS client subnet option (ECS (EDNS Client Subnet) option), which contains the client’s IP address for DNS The server better determines the IP address corresponding to the domain name requested by the client based on the IP address of the client. Since the IP address of the terminal device does not reflect the location of the terminal device, in this application, the SMF network element sends the IP address corresponding to the first application platform as the second information to the first UPF network element. The element can add the second information as an ECS option to the first request, obtain the second request, and send the second request to the first DNS server, so that the first DNS server can better determine the terminal device request query according to the ECS option The IP address corresponding to the first domain name. Therefore, the second information can be represented by ECS option list. The ECS option list contains at least one ECS option. If there are multiple first application platforms, the ECS option list includes multiple ECS options. Each ECS option includes an IP address. Among them, the IP address included in the ECS option is the corresponding IP address of the application platform. The description of the IP address can refer to the previous description, and the repetition will not be repeated.

可以理解为，一个应用平台对应的IP地址可以代表该应用平台的位置信息，因此，SMF网元将第一应用平台对应的IP地址作为第二信息发送给第一UPF网元，第一UPF网元可以将第一应用平台对应的IP地址添加到第一请求，得到第二请求，并向第一DNS服务器发送第二请求，以便第一DNS服务器根据第一应用平台的位置信息确定第一域名对应的第一IP地址。It can be understood that the IP address corresponding to an application platform can represent the location information of the application platform. Therefore, the SMF network element sends the IP address corresponding to the first application platform as the second information to the first UPF network element. The meta can add the IP address corresponding to the first application platform to the first request, obtain the second request, and send the second request to the first DNS server, so that the first DNS server determines the first domain name according to the location information of the first application platform The corresponding first IP address.

第三种可能的形式：若第一信息还包括第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址。第二信息包括第一本地DNS服务器的IP地址，第一本地DNS服务器为第一应用平台提供服务。A third possible form: if the first information further includes the IP addresses of the local DNS servers respectively corresponding to at least one application platform where the first application is located. The second information includes the IP address of the first local DNS server, and the first local DNS server provides services for the first application platform.

其中，SMF网元根据第一信息和终端设备的位置信息，在至少一个应用平台中确定第一应用平台，进一步地，由于应用平台与应用平台对应的本地DNS服务器的IP地址存在对应关系，因此，在确定第一应用平台后，SMF网元根据第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址确定第一本地DNS服务器的IP地址，作为第二信息。Wherein, the SMF network element determines the first application platform in at least one application platform according to the first information and the location information of the terminal device. Further, since the application platform has a corresponding relationship with the IP address of the local DNS server corresponding to the application platform, After determining the first application platform, the SMF network element determines the IP address of the first local DNS server according to the IP addresses of the local DNS servers respectively corresponding to the at least one application platform where the first application is located, as the second information.

例如，第一信息包括第一域名FQDN-A，第一域名对应的第一应用的标识APP ID-1，第一应用所在的至少一个应用平台的位置信息包括DNAI1(对应MEC-1)和DNAI2(对应MEC-2)，第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址包括local DNS server IP-1(对应DNAI1)和local DNS server IP-2(对应DNAI2)。SMF网元可以根据终端设备的位置信息和第一信息可以从DNAI1和DNAI2中确定DNAI1，并根据DNAI1将local DNS server IP-1作为第二信息。For example, the first information includes the first domain name FQDN-A, the identification APP ID-1 of the first application corresponding to the first domain name, and the location information of at least one application platform where the first application is located includes DNAI1 (corresponding to MEC-1) and DNAI2 (Corresponding to MEC-2), the IP addresses of the local DNS servers respectively corresponding to at least one application platform where the first application is located include local DNS server IP-1 (corresponding to DNAI1) and local DNS server IP-2 (corresponding to DNAI2). The SMF network element can determine DNAI1 from DNAI1 and DNAI2 according to the location information of the terminal device and the first information, and use the local DNS server IP-1 as the second information according to DNAI1.

在本申请中，第一应用平台可以理解为本地应用平台或者MEC平台，那么服务第一应用平台的本地DNS服务器称为第一本地DNS服务器。此外，如果第一应用所在的至少一个应用平台包括多个本地应用平台或者多个MEC平台，那么服务该本地应用平台或者该MEC平台服务的本地DNS服务器可能存在多个。可以理解为，若第一应用平台的数目为多个，且多个第一应用平台分别对应的本地DNS服务器也是多个，则在这种情况下，SMF网元可以基于本地策略选择一个本地DNS服务器作为第一本地DNS服务器。在一种实现方式中，SMF网元基于多个本地DNS服务器中每一个本地DNS服务器的负载情况，将负载较轻的本地DNS服务器作为第一本地DNS服务器。在另一种实现方式中，SMF网元基于多个本地DNS服务器中每一个本地DNS服务器支持的域名查询列表，将支持的域名查询列表较多的本地DNS服务器作为第一本地DNS服务器。另一种实现方式中，SMF网元可以基于多个第一应用平台的负载情况，将负载较轻的应用平台作为目标应用平台，进一步地，确定目标应用平台对应的本地DNS服务器作为第一本地DNS服务器。In this application, the first application platform can be understood as a local application platform or an MEC platform, and the local DNS server serving the first application platform is called the first local DNS server. In addition, if at least one application platform on which the first application is located includes multiple local application platforms or multiple MEC platforms, there may be multiple local DNS servers serving the local application platform or the MEC platform. It can be understood that if the number of first application platforms is multiple, and the local DNS servers corresponding to the multiple first application platforms are also multiple, in this case, the SMF network element can select a local DNS based on the local policy. The server serves as the first local DNS server. In an implementation manner, the SMF network element uses the local DNS server with a lighter load as the first local DNS server based on the load condition of each local DNS server in the multiple local DNS servers. In another implementation manner, the SMF network element uses the local DNS server with more supported domain name query lists as the first local DNS server based on the domain name query list supported by each of the multiple local DNS servers. In another implementation manner, the SMF network element can use the lighter-loaded application platform as the target application platform based on the load conditions of multiple first application platforms, and further, determine the local DNS server corresponding to the target application platform as the first local DNS server.

因此，SMF网元将第一本地DNS服务器的IP地址作为第二信息发送给第一UPF网元，第一UPF网元将第一请求的目标地址修改为第一本地DNS服务器的IP地址，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为第一本地DNS服务器，以便第一本地DNS服务器确定第一域名对应的第一IP地址。Therefore, the SMF network element sends the IP address of the first local DNS server as the second information to the first UPF network element, and the first UPF network element modifies the target address of the first request to the IP address of the first local DNS server to obtain And send the second request to the first DNS server, where the first DNS server is the first local DNS server, so that the first local DNS server determines the first IP address corresponding to the first domain name.

基于以上相同的构思，SMF网元可以获取域名、应用的标识和应用所在至少一个应用平台的位置信息的对应关系，如表1所示。Based on the same concept as above, the SMF network element can obtain the corresponding relationship between the domain name, the identification of the application, and the location information of at least one application platform where the application is located, as shown in Table 1.

表1Table 1

其中，表1可以理解为整个网络中部署的全部应用的标识、与全部应用中的每个应用对应的域名以及全部应用中的每个应用所在至少一个应用平台的位置信息的对应关系(以下简称为第一种类型的对应关系)，也可以理解为整个网络中部署的部分应用的标识、与部分应用中的每个应用对应的域名以及部分应用中的每个应用所在至少一个应用平台的位置信息的对应关系(以下简称为第二种类型的对应关系)。为了简洁，本申请将整个网络中部署的全部的应用简称为全部应用。本申请将整个网络中部署的部分应用简称为部分应用。Among them, Table 1 can be understood as the correspondence between the identifiers of all applications deployed in the entire network, the domain names corresponding to each application in all applications, and the location information of at least one application platform where each application in all applications is located (hereinafter referred to as Is the first type of correspondence), which can also be understood as the identification of some applications deployed in the entire network, the domain name corresponding to each application in some applications, and the location of at least one application platform where each application in some applications is located Information correspondence (hereinafter referred to as the second type of correspondence). For the sake of brevity, this application abbreviates all applications deployed in the entire network as all applications. In this application, some applications deployed in the entire network are referred to as partial applications for short.

在一种可能的设计中，针对当前发起PDU会话的终端设备，若SMF网元本地配置第一种类型的对应关系，则SMF网元可以根据第一种类型的对应关系和当前终端设备签约的多个应用相关的信息中包括的多个应用的标识，确定终端设备签约的多个应用的标识、与终端设备签约的多个应用中的每个应用对应的域名以及终端设备签约的多个应用中的每个应用所在至少一个应用平台的位置信息的对应关系。其中，SMF网元获取当前终端设备签约的多个应用相关的信息可以采用以下实现方式：在终端设备发起PDU会话建立过程中，在SMF网元调用PCF网元请求从PCF网元获取该PDU会话相关的策略信息后，PCF网元调用UDR的服务化操作请求，从UDR获取该终端设备签约的多个应用相关的信息，其中，终端设备签约的多个应用相关的信息包括终端设备签约的多个应用的标识。In a possible design, for the terminal device currently initiating a PDU session, if the SMF network element locally configures the first type of correspondence, the SMF network element can contract with the current terminal device according to the first type of correspondence The identification of multiple applications included in the information related to multiple applications, the identification of multiple applications contracted by the terminal device, the domain name corresponding to each of the multiple applications contracted by the terminal device, and the multiple applications contracted by the terminal device Correspondence of the location information of at least one application platform where each application in. Among them, the SMF network element can obtain information related to multiple applications contracted by the current terminal device in the following manner: in the process of establishing a PDU session initiated by the terminal device, the SMF network element calls the PCF network element to request the PDU session to be obtained from the PCF network element After the relevant policy information, the PCF network element invokes the service operation request of the UDR, and obtains the information related to multiple applications subscribed by the terminal device from the UDR. Among them, the multiple application related information subscribed by the terminal device includes the multiple subscribed information of the terminal device. The ID of an application.

在一种可能的设计中，若SMF网元未在本地配置第一种类型的对应关系，在终端设备发起PDU会话建立过程中，在SMF网元调用PCF网元请求从PCF网元获取该PDU会话相关的策略信息后，PCF网元调用UDR的服务化操作请求，从UDR获取该终端设备签约的多个应用相关的信息和第一种类型的对应关系，其中，终端设备签约的多个应用相关的信息包括终端设备签约的多个应用的标识。PCF网元生成策略计费控制规则(Policy and Charging Control rule,PCC rule)，PCC rule包括该终端设备签约的多个应用相关的信息和第一种类型的对应关系，SMF网元保存PCC rule。此时，SMF网元可以保存第一种类型的对应关系，当其他终端设备发起PDU会话建立过程时无需再次获取第一种类型的对应关系。In a possible design, if the SMF network element is not locally configured with the first type of correspondence, when the terminal device initiates the PDU session establishment process, the SMF network element calls the PCF network element to request the PDU from the PCF network element After the session-related policy information, the PCF network element invokes the service operation request of the UDR, and obtains the information related to the multiple applications subscribed by the terminal device and the corresponding relationship of the first type from the UDR. Among them, multiple applications subscribed by the terminal device The related information includes the identities of multiple applications subscribed by the terminal device. The PCF network element generates a Policy and Charging Control rule (PCC rule). The PCC rule includes the correspondence between multiple applications contracted by the terminal device and the first type, and the SMF network element stores the PCC rule. At this time, the SMF network element can save the corresponding relationship of the first type, and there is no need to obtain the corresponding relationship of the first type again when other terminal devices initiate the PDU session establishment process.

在又一种可能的设计中，若SMF网元未在本地配置第一种类型的对应关系，在终端设备发起PDU会话建立过程中，在SMF网元调用PCF网元请求从PCF网元获取该PDU会话相关的策略信息后，PCF网元调用UDR的服务化操作请求，从UDR获取该终端设备签约的多个应用相关的信息和第一种类型的对应关系，其中，终端设备签约的多个应用相关的信息包括终端设备签约的多个应用的标识。PCF网元根据第一种类型的对应关系和终端设备签约的多个应用的标识，确定终端设备签约的多个应用的标识、与终端设备签约的多个应用中的每个应用对应的域名以及终端设备签约的多个应用中的每个应用所在至少一个应用平台的位置信息的对应关系，记为表1*。PCF网元生成PCC rule，PCC rule包括表1*，通过服务化操作策略建立控制响应下发至SMF网元，SMF网元保存PCC rule。此时，SMF网元获得的终端设备签约的多个应用对应的域名、终端设备签约的多个应用的标识和终端设备签约的多个应用所在至少一个应用平台的位置信息的对应关系为第二种类型的对应关系。In another possible design, if the SMF network element is not locally configured with the first type of correspondence, the SMF network element calls the PCF network element to request the PCF network element to obtain the corresponding relationship when the terminal device initiates the PDU session establishment process. After the policy information related to the PDU session, the PCF network element invokes the service operation request of the UDR, and obtains the information related to the multiple applications subscribed by the terminal device and the corresponding relationship of the first type from the UDR. Among them, the multiple subscribed terminal devices The application-related information includes the identities of multiple applications subscribed by the terminal device. The PCF network element determines the identities of the multiple applications signed by the terminal device, the domain name corresponding to each of the multiple applications signed by the terminal device, and The corresponding relationship of the location information of at least one application platform where each of the multiple applications subscribed by the terminal device is located is recorded as Table 1*. The PCF network element generates a PCC rule. The PCC rule includes Table 1*, and sends a control response to the SMF network element through the establishment of a service-based operation strategy, and the SMF network element saves the PCC rule. At this time, the correspondence between the domain names corresponding to the multiple applications contracted by the terminal device, the identifications of the multiple applications contracted by the terminal device, and the location information of at least one application platform where the multiple applications contracted by the terminal device are obtained by the SMF network element is the second Correspondence of various types.

进一步地，SMF网元根据终端设备的位置信息，终端设备签约的多个应用的标识、与终端设备签约的多个应用中的每个应用对应的域名以及终端设备签约的多个应用中的每个应用所在至少一个应用平台的位置信息的对应关系确定多个域名中每个域名对应的DNAI list。其中，多个域名是指与终端设备签约的多个应用中的每个应用对应的域名。Further, the SMF network element is based on the location information of the terminal device, the identities of the multiple applications contracted by the terminal device, the domain name corresponding to each of the multiple applications contracted by the terminal device, and each of the multiple applications contracted by the terminal device. The correspondence between the location information of at least one application platform where each application is located determines the DNAI list corresponding to each domain name in the multiple domain names. The multiple domain names refer to the domain names corresponding to each of the multiple applications contracted by the terminal device.

示例性地，UE签约的应用相关的信息包括APP-1和APP-2。其中，APP-1对应FQDN-A，APP-2对应FQDN-B。SMF网元根据UE的位置信息(TAI)和表1，从FQDN-A对应的DNAI1和DNAI2中确定DNAI1，从FQDN-B对应的DNAI2和DNAI3中确定DNAI2和DNAI3，即分别确定每个域名对应的DNAI list，其中，每个域名对应的DNAI list包括至少一个DNAI，如表2所示。Exemplarily, the information related to the application subscribed by the UE includes APP-1 and APP-2. Among them, APP-1 corresponds to FQDN-A, and APP-2 corresponds to FQDN-B. SMF network element determines DNAI1 from DNAI1 and DNAI2 corresponding to FQDN-A according to the location information (TAI) of the UE and Table 1, and determines DNAI2 and DNAI3 from DNAI2 and DNAI3 corresponding to FQDN-B, which means that each domain name corresponds to each domain name. The DNAI list of each domain name includes at least one DNAI, as shown in Table 2.

表2Table 2

在一种可能的设计中，在SMF网元确定多个域名中每个域名对应的DNAI list后，SMF网元将多个域名中每个域名对应的DNAI list发送至第一UPF网元。In a possible design, after the SMF network element determines the DNAI list corresponding to each domain name in the multiple domain names, the SMF network element sends the DNAI list corresponding to each domain name in the multiple domain names to the first UPF network element.

示例性地，在SMF网元得到表2后，进一步根据表2确定FQDN-A对应的DNAI list和FQDN-B对应的DNAI list，如表3所示，将表3发送至第一UPF网元。Exemplarily, after the SMF network element obtains Table 2, it further determines the DNAI list corresponding to FQDN-A and the DNAI list corresponding to FQDN-B according to Table 2. As shown in Table 3, Table 3 is sent to the first UPF network element .

表3table 3

在一种可能的设计中，在SMF网元确定多个域名中每个域名对应的DNAI list后，SMF网元根据应用平台与应用平台对应的IP地址的对应关系，确定多个域名中每个域名对应的ECS option list，并将多个域名中每个域名对应的ECS option list发送至第一UPF网元。In a possible design, after the SMF network element determines the DNAI list corresponding to each domain name in the multiple domain names, the SMF network element determines each of the multiple domain names according to the correspondence between the application platform and the IP address corresponding to the application platform. The ECS option list corresponding to the domain name, and the ECS option list corresponding to each of the multiple domain names is sent to the first UPF network element.

示例性地，SMF网元可以本地配置应用平台与应用平台对应的IP地址的对应关系，如表4所示，SMF网元根据表2和表4得到表5，其中，表5中的第4列是根据表4得到，进一步根据表5确定FQDN-A对应的ECS option list和FQDN-B对应的ECS option list，如表6所示，将表6发送至第一UPF网元。Exemplarily, the SMF network element can locally configure the correspondence relationship between the application platform and the IP address corresponding to the application platform. As shown in Table 4, the SMF network element obtains Table 5 according to Tables 2 and 4, where the fourth The columns are obtained according to Table 4. The ECS option list corresponding to FQDN-A and the ECS option list corresponding to FQDN-B are further determined according to Table 5. As shown in Table 6, Table 6 is sent to the first UPF network element.

表4Table 4

表5table 5

表6Table 6

在一种可能的设计中，在SMF网元确定多个域名中每个域名对应的DNAI list后，SMF网元根据应用平台与应用平台对应的本地DNS服务器的IP地址的对应关系，确定多个域名中每个域名对应的第一本地DNS服务器的IP地址，将多个域名中每个域名对应的第一本地DNS服务器的IP地址发送至第一UPF网元。In a possible design, after the SMF network element determines the DNAI list corresponding to each of the multiple domain names, the SMF network element determines multiple The IP address of the first local DNS server corresponding to each domain name in the domain names is sent to the first UPF network element.

示例性地，SMF网元可以本地配置应用平台与应用平台对应的本地DNS服务器的IP地址的对应关系，如表7所示，SMF网元根据表2和表7得到表8，其中，表8中的第4列是根据表7得到，进一步根据表8确定FQDN-A对应的第一本地DNS服务器的IP地址和FQDN-B对应的第一本地DNS服务器的IP地址，如表9所示，将表9发送至第一UPF网元。Exemplarily, the SMF network element can locally configure the correspondence between the application platform and the IP address of the local DNS server corresponding to the application platform. As shown in Table 7, the SMF network element obtains Table 8 according to Tables 2 and 7, where Table 8 The fourth column in is obtained according to Table 7, and further according to Table 8 to determine the IP address of the first local DNS server corresponding to FQDN-A and the IP address of the first local DNS server corresponding to FQDN-B, as shown in Table 9. Send Table 9 to the first UPF network element.

表7Table 7

表8Table 8

表9Table 9

应理解的是，上述各个举例，不作为本申请的限定。It should be understood that the above examples are not a limitation of this application.

步骤620：SMF网元向第一UPF网元发送第一域名和第二信息。Step 620: The SMF network element sends the first domain name and the second information to the first UPF network element.

示例性地，SMF网元根据数据网络名称(data network name，DNN)和单网络切片选择辅助信息(single network slice selection assistance information，S-NSSAI)等参数选择第一UPF网元作为终端设备的PDU会话的锚点，SMF网元向第一UPF网元发送N4会话(N4session)建立请求消息，N4会话建立请求消息中需要携带第一域名和第二信息。示例性地，N4会话建立请求消息中携带域名翻译表(translation table)。其中，translation table包括第一域名和第二信息。Exemplarily, the SMF network element selects the first UPF network element as the PDU of the terminal device according to parameters such as data network name (DNN) and single network slice selection assistance information (S-NSSAI). The anchor point of the session, the SMF network element sends an N4 session (N4session) establishment request message to the first UPF network element, and the N4 session establishment request message needs to carry the first domain name and the second information. Exemplarily, the N4 session establishment request message carries a domain name translation table. Among them, the translation table includes the first domain name and the second information.

应理解的是，在时序上，上述步骤600～步骤620是在步骤630之前执行的，示例性地，在终端设备的PDU会话建立过程中执行上述步骤600～步骤620。It should be understood that, in terms of time sequence, the foregoing steps 600 to 620 are performed before step 630. Illustratively, the foregoing steps 600 to 620 are performed during the establishment of a PDU session of the terminal device.

步骤630：第一UPF网元接收来自于终端设备的第一请求，第一请求包括第一域名。Step 630: The first UPF network element receives a first request from the terminal device, where the first request includes the first domain name.

应理解的是，第一UPF网元根据第一域名查询是否保存与第一域名对应的第二信息，即第一UPF网元从SMF网元接收过与第一域名对应的第二信息，若存在则执行步骤640，否则，第一UPF网元转发该第一请求至第一请求的目标地址指示的DNS服务器或DNS代理。It should be understood that the first UPF network element queries whether to save the second information corresponding to the first domain name according to the first domain name, that is, the first UPF network element has received the second information corresponding to the first domain name from the SMF network element, if If it exists, perform step 640; otherwise, the first UPF network element forwards the first request to the DNS server or DNS proxy indicated by the target address of the first request.

例如，第一UPF接收来自于SMF网元的N4会话建立请求消息，N4会话建立请求消息携带translation table，translation table包括表6。若第一UPF网元接收来自于UE的第一请求，第一请求包括FQDN-A，则第一UPF网元根据表6查询FQDN-A，确定存在与 FQDN-A对应的ECS option(IP-1)，并进一步执行步骤640。若第一UPF网元接收来自于UE的第一请求，第一请求包括FQDN-E，则第一UPF网元根据表12查询FQDN-E，确定不存在与FQDN-A对应的ECS option，并进一步转发该第一请求至第一请求的目标地址指示的DNS服务器或DNS代理。For example, the first UPF receives the N4 session establishment request message from the SMF network element, and the N4 session establishment request message carries a translation table, and the translation table includes Table 6. If the first UPF network element receives the first request from the UE, and the first request includes FQDN-A, the first UPF network element queries FQDN-A according to Table 6, and determines that there is an ECS option (IP- 1), and further execute step 640. If the first UPF network element receives the first request from the UE, and the first request includes FQDN-E, the first UPF network element queries FQDN-E according to Table 12, determines that there is no ECS option corresponding to FQDN-A, and The first request is further forwarded to the DNS server or DNS proxy indicated by the target address of the first request.

步骤640：第一UPF网元根据第二信息确定第二请求，并向第一DNS服务器发送第二请求，第二请求用于在终端设备位于第一位置时获取第一域名对应的第一IP地址。其中，终端设备的位置信息指示终端设备处于第一位置。Step 640: The first UPF network element determines the second request according to the second information, and sends the second request to the first DNS server. The second request is used to obtain the first IP corresponding to the first domain name when the terminal device is located in the first location. address. Wherein, the location information of the terminal device indicates that the terminal device is in the first position.

应理解的是，基于步骤610中第二信息的三种不同形式，第一UPF网元根据第二信息确定第二请求，并向第一DNS服务器发送第二请求也可以包括以下三种情况：It should be understood that, based on the three different forms of the second information in step 610, the first UPF network element determines the second request according to the second information and sends the second request to the first DNS server may also include the following three situations:

情况1：与步骤610中第一种可能的形式对应，第二信息包括第一应用平台对应的DNAI。第一UPF网元将第一应用平台对应的DNAI添加至第一请求，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为集中DNS服务器。Case 1: Corresponding to the first possible format in step 610, the second information includes the DNAI corresponding to the first application platform. The first UPF network element adds the DNAI corresponding to the first application platform to the first request, obtains the second request, and sends the second request to the first DNS server, which is a centralized DNS server.

例如，若第一UPF网元接收来自于UE的第一请求，第一请求包括FQDN-A，则第一UPF网元根据表3查询FQDN-A，确定存在与FQDN-A对应的DNAI list(包括DNAI1)，并进一步将与FQDN-A对应的DNAI list添加至第一请求，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为集中DNS服务器。For example, if the first UPF network element receives the first request from the UE, and the first request includes FQDN-A, the first UPF network element queries FQDN-A according to Table 3, and determines that there is a DNAI list ( Including DNAI1), and further adding the DNAI list corresponding to FQDN-A to the first request, obtaining the second request, and sending the second request to the first DNS server, which is a centralized DNS server.

情况2：与步骤610中第二种可能的形式对应，第二信息包括第一应用平台对应的IP地址。第一UPF网元将第一应用平台对应的IP地址添加至第一请求，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为集中DNS服务器。Case 2: Corresponding to the second possible form in step 610, the second information includes the IP address corresponding to the first application platform. The first UPF network element adds the IP address corresponding to the first application platform to the first request, obtains the second request, and sends the second request to the first DNS server, which is a centralized DNS server.

例如，若第一UPF网元接收来自于UE的第一请求，第一请求包括FQDN-A，则第一UPF网元根据表6查询FQDN-A，确定存在与FQDN-A对应的ECS option(包括IP-1)，并进一步将与FQDN-A对应的ECS option添加至第一请求，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为集中DNS服务器。For example, if the first UPF network element receives the first request from the UE, and the first request includes FQDN-A, the first UPF network element queries FQDN-A according to Table 6, and determines that there is an ECS option corresponding to FQDN-A. Include IP-1), and further add the ECS option corresponding to FQDN-A to the first request, obtain the second request, and send the second request to the first DNS server, which is a centralized DNS server.

情况3：与步骤610中第三种可能的形式对应，第二信息包括第一本地DNS服务器的IP地址。第一UPF网元将第一请求的目标地址修改为第一本地DNS服务器的IP地址，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为第一本地DNS服务器。Case 3: Corresponding to the third possible form in step 610, the second information includes the IP address of the first local DNS server. The first UPF network element modifies the target address of the first request to the IP address of the first local DNS server, obtains the second request, and sends the second request to the first DNS server, which is the first local DNS server .

例如，若第一UPF网元接收来自于UE的第一请求，第一请求包括FQDN-A，则第一UPF网元根据表9查询FQDN-A，确定存在与FQDN-A对应的local DNS server IP-1，并进一步将第一请求的目标地址修改为与FQDN-A对应的local DNS server IP-1，获得第二请求，并将第二请求发送至local DNS server IP-1对应的本地DNS服务器。For example, if the first UPF network element receives the first request from the UE, and the first request includes FQDN-A, the first UPF network element queries FQDN-A according to Table 9 and determines that there is a local DNS server corresponding to FQDN-A IP-1, and further modify the target address of the first request to the local DNS server IP-1 corresponding to FQDN-A, obtain the second request, and send the second request to the local DNS server IP-1 corresponding to the local DNS server.

此外，在一种可能的设计中，SMF网元还向第一UPF网元发送第一指示信息，第一指示信息用于指示第一UPF网元在接收到来自于终端设备的第一请求且第一请求包括第一域名时，根据第二信息确定第二请求，并将第二请求发送至第一DNS服务器。In addition, in a possible design, the SMF network element also sends first indication information to the first UPF network element, where the first indication information is used to indicate that the first UPF network element is receiving the first request from the terminal device and When the first request includes the first domain name, the second request is determined according to the second information, and the second request is sent to the first DNS server.

其中，第一指示信息可以与第二信息同时发送，也可以与第二信息分开发送。示例性地，SMF网元在选择第一UPF网元作为终端设备的PDU会话的锚点后，SMF向第一UPF发送N4会话建立请求消息，N4会话建立请求消息中需要携带translation table和第一指示信息。translation table包括第一域名和第二信息。Wherein, the first indication information may be sent at the same time as the second information, or may be sent separately from the second information. Exemplarily, after the SMF network element selects the first UPF network element as the anchor point of the PDU session of the terminal device, the SMF sends an N4 session establishment request message to the first UPF. The N4 session establishment request message needs to carry the translation table and the first Instructions. The translation table includes the first domain name and the second information.

应理解的是，基于步骤610中第二信息的三种不同形式，第一指示信息可以具体包括以下三种可能的形式：It should be understood that, based on the three different forms of the second information in step 610, the first indication information may specifically include the following three possible forms:

第一种可能的形式：与步骤610中第一种可能的形式对应，第一指示信息用于指示第一UPF网元在接收到来自于终端设备的第一请求且第一请求包括第一域名时，将第一应用平台对应的DNAI添加至第一请求，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为集中DNS服务器。The first possible form: corresponding to the first possible form in step 610, the first indication information is used to indicate that the first UPF network element is receiving the first request from the terminal device and the first request includes the first domain name At this time, the DNAI corresponding to the first application platform is added to the first request, the second request is obtained, and the second request is sent to the first DNS server, which is a centralized DNS server.

第二种可能的形式：与步骤610中第二种可能的形式对应，第一指示信息用于指示第一UPF网元在接收到来自于终端设备的第一请求且第一请求包括第一域名时，将第一应用平台对应的IP地址添加至第一请求，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为集中DNS服务器。The second possible form: corresponding to the second possible form in step 610, the first indication information is used to indicate that the first UPF network element is receiving the first request from the terminal device and the first request includes the first domain name At this time, the IP address corresponding to the first application platform is added to the first request, the second request is obtained, and the second request is sent to the first DNS server, which is a centralized DNS server.

第三种可能的形式：与步骤610中第三种可能的形式对应，第一指示信息用于指示第一UPF网元在接收到来自于终端设备的第一请求且第一请求包括第一域名时，将第一请求的目标地址修改为第一本地DNS服务器的IP地址，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为第一本地DNS服务器。The third possible form: corresponding to the third possible form in step 610, the first indication information is used to indicate that the first UPF network element is receiving the first request from the terminal device and the first request includes the first domain name At this time, the target address of the first request is modified to the IP address of the first local DNS server, the second request is obtained, and the second request is sent to the first DNS server, which is the first local DNS server.

此外，在一种可能的设计中，第一UPF网元向SMF网元发送第四信息，第四信息包括第一应用所在的第二应用平台对应的DNAI或者第一应用所在的第二应用平台对应的IP地址、第一IP地址中的至少一种。其中，第一IP地址为部署在第二应用平台上的第一应用的服务器的IP地址。SMF网元基于第四信息为终端设备的PDU会话选择ULCL或BP，以及本地PDU会话锚点，以实现DNS服务器将距离终端设备较近的应用服务器的IP地址返回给终端设备之后，把业务流量选择性的路由到应用服务器所在的应用平台。In addition, in a possible design, the first UPF network element sends fourth information to the SMF network element. The fourth information includes the DNAI corresponding to the second application platform where the first application is located or the second application platform where the first application is located. At least one of the corresponding IP address and the first IP address. The first IP address is the IP address of the server of the first application deployed on the second application platform. The SMF network element selects ULCL or BP for the PDU session of the terminal device based on the fourth information, and the local PDU session anchor point, so that the DNS server returns the IP address of the application server closer to the terminal device to the terminal device, and then transfers the service flow Selectively route to the application platform where the application server is located.

应理解的是，第二应用平台为至少一个第一应用平台中的一个应用平台。若第一应用平台的数目为一个，则第二应用平台与第一应用平台相同，若第一应用平台的数目为多个，则第二应用平台为多个第一应用平台中的一个。It should be understood that the second application platform is one of the at least one first application platform. If the number of the first application platform is one, the second application platform is the same as the first application platform, and if the number of the first application platform is multiple, the second application platform is one of the multiple first application platforms.

示例性地，第二信息用ECS option list表示，ECS option list包括第一应用平台对应的IP地址。若第一应用平台的数目为多个，则ECS option list包括多个IP地址，DNS服务器可以根据本地策略从ECS option list中确定目标ECS option和目标应用平台。在一种实现方式中，DNS服务器基于ECS option list中包括多个IP地址确定多个应用平台，并进一步基于多个应用平台的负载情况，将负载较轻的应用平台作为目标应用平台，并将包括该目标应用平台对应的IP地址的ECS option作为目标ECS option。DNS服务器将目标应用平台对应的DNAI、或目标应用平台对应的IP地址发送给第一UPF网元。其中，目标应用平台为第二应用平台。Exemplarily, the second information is represented by an ECS option list, and the ECS option list includes the IP address corresponding to the first application platform. If there are multiple first application platforms, the ECS option list includes multiple IP addresses, and the DNS server can determine the target ECS option and target application platform from the ECS option list according to the local policy. In one implementation, the DNS server determines multiple application platforms based on the multiple IP addresses included in the ECS option list, and further based on the load conditions of multiple application platforms, the application platform with a lighter load is used as the target application platform, and The ECS option that includes the IP address corresponding to the target application platform is used as the target ECS option. The DNS server sends the DNAI corresponding to the target application platform or the IP address corresponding to the target application platform to the first UPF network element. Among them, the target application platform is the second application platform.

进一步地，当终端设备发生了移动，例如，终端设备从当前应用平台的服务区域进入另一个应用平台的服务区域，那么终端设备之前请求的第一IP地址对终端设备的当前的位置来说，已经不再优化，终端设备需要刷新DNS缓存记录，并再次请求第一域名，更新第一IP地址。Further, when the terminal device moves, for example, the terminal device enters the service area of another application platform from the service area of the current application platform, the first IP address previously requested by the terminal device is relative to the current location of the terminal device. It is no longer optimized, and the terminal device needs to refresh the DNS cache record, request the first domain name again, and update the first IP address.

在第一UPF网元将第二请求发送至第一DNS服务器之后，第一UPF接收来自于第一DNS服务器的针对第一请求的响应消息，该响应消息包括第一IP地址、第一域名对应的DNS缓存记录的存留时间(time to live，TTL)。此外，该响应消息还可以包括第一应用所在的第二应用平台对应的DNAI或第一应用所在的第二应用平台对应的IP地址。第一UPF保存该响应消息，并向SMF网元发送第四信息。第四信息包括第一应用所在的第二应用平台对应的DNAI或者第一应用所在的第二应用平台对应的IP地址、第一IP地址中的至少一种。After the first UPF network element sends the second request to the first DNS server, the first UPF receives a response message from the first DNS server for the first request, and the response message includes the first IP address and the corresponding first domain name. The time to live (TTL) of the DNS cache record. In addition, the response message may also include the DNAI corresponding to the second application platform where the first application is located or the IP address corresponding to the second application platform where the first application is located. The first UPF saves the response message, and sends the fourth message to the SMF network element. The fourth information includes at least one of the DNAI corresponding to the second application platform where the first application is located, or the IP address corresponding to the second application platform where the first application is located, and the first IP address.

在一种可能的设计中，当终端设备发生了移动，SMF网元获取更新后的终端设备的位置信息，并根据第一信息和更新后的终端设备的位置信息，在至少一个应用平台中确定第三应用平台；其中，第三应用平台与第二应用平台不同。SMF网元向第一UPF网元发送第一域名和更新后的第二信息，更新后的第二信息与第三应用平台对应。第一UPF网元向SMF网元发送通知消息，通知消息用于指示SMF网元通知终端设备发送第三请求，第三请求包括第一域名。此外，在第一UPF网元向SMF网元发送通知消息之前，第一用户面网元判断第一域名对应的DNS缓存记录的TTL是否超过预设时长，若是，则第一UPF网元向SMF网元发送通知消息，否则，第一UPF网元可以不发送该通知消息。进一步地，在SMF网元接收到该通知消息后，SMF网元向终端设备发送非接入层(Non-Access Stratum，NAS)消息，NAS消息包括该通知消息。因此，采用上述设计可以提高DNS缓存记录刷新的准确度，保证用户体验，能够实现随着终端设备的位置变化优化终端设备访问域名对应的IP地址。In a possible design, when the terminal device moves, the SMF network element obtains the updated location information of the terminal device, and determines in at least one application platform based on the first information and the updated location information of the terminal device The third application platform; among them, the third application platform is different from the second application platform. The SMF network element sends the first domain name and the updated second information to the first UPF network element, and the updated second information corresponds to the third application platform. The first UPF network element sends a notification message to the SMF network element, where the notification message is used to instruct the SMF network element to notify the terminal device to send a third request, and the third request includes the first domain name. In addition, before the first UPF network element sends the notification message to the SMF network element, the first user plane network element determines whether the TTL of the DNS cache record corresponding to the first domain name exceeds the preset time period, and if so, the first UPF network element sends the SMF The network element sends the notification message; otherwise, the first UPF network element may not send the notification message. Further, after the SMF network element receives the notification message, the SMF network element sends a Non-Access Stratum (NAS) message to the terminal device, and the NAS message includes the notification message. Therefore, the adoption of the above design can improve the accuracy of DNS cache record refresh, ensure user experience, and can optimize the IP address corresponding to the domain name that the terminal device accesses as the location of the terminal device changes.

综上所述，SMF网元获取第一信息，至少根据UE的位置信息和第一信息确定第二信息，并向第一UPF网元发送第一域名和第二信息。第一UPF网元在接收来自于终端设备的第一请求且第一请求包括第一域名时，第一UPF网元根据第二信息确定第二请求，并向第一DNS服务器发送第二请求，以便第一DNS服务器获取的第一域名对应的第一IP地址。当终端设备在终端设备的位置信息所指示的位置采用第一IP地址访问第一域名时，能够实现终端设备就近访问本地业务，可以降低访问业务的时延，进而可以提高通信效率。In summary, the SMF network element obtains the first information, determines the second information at least according to the location information of the UE and the first information, and sends the first domain name and the second information to the first UPF network element. When the first UPF network element receives the first request from the terminal device and the first request includes the first domain name, the first UPF network element determines the second request according to the second information, and sends the second request to the first DNS server, So that the first IP address corresponding to the first domain name obtained by the first DNS server. When the terminal device uses the first IP address to access the first domain name at the location indicated by the location information of the terminal device, the terminal device can access the local service nearby, can reduce the time delay of accessing the service, and can improve the communication efficiency.

需要注意的是，在如图6所示的实施例中，SMF网元在终端设备的PDU会话建立过程中向第一UPF网元发送第一域名和第二信息。本申请实施例还提供一种发现应用的方法，如图7所示，SMF网元根据第一信息确定第三信息，并提前将第一域名和第三信息发送至第一UPF网元。当终端设备发起PDU会话建立时，SMF网元根据终端设备的位置信息和第一信息确定第二信息，向第一UPF网元发送第一域名和第二信息。采用如图7所示的实施例可以减少PDU会话建立过程中N4接口上传输负荷。此时，第三信息和第二信息的具体内容详见如图7所示的实施例中的相关描述。It should be noted that, in the embodiment shown in FIG. 6, the SMF network element sends the first domain name and the second information to the first UPF network element during the establishment of the PDU session of the terminal device. The embodiment of the present application also provides a method for discovering applications. As shown in FIG. 7, the SMF network element determines third information according to the first information, and sends the first domain name and the third information to the first UPF network element in advance. When the terminal device initiates the establishment of a PDU session, the SMF network element determines the second information according to the location information of the terminal device and the first information, and sends the first domain name and the second information to the first UPF network element. The embodiment shown in FIG. 7 can reduce the transmission load on the N4 interface during the establishment of the PDU session. At this time, for the specific content of the third information and the second information, refer to the related description in the embodiment shown in FIG. 7.

如图7所示，本申请实施例还提供一种发现应用的方法，该方法用于实现DNS服务器将距离终端设备较近的应用服务器的IP地址返回给终端设备以使得终端设备能够就近访问本地业务。该方法包括：As shown in FIG. 7, the embodiment of the present application also provides a method for discovering applications. The method is used to realize that the DNS server returns the IP address of the application server closer to the terminal device to the terminal device so that the terminal device can access the local device nearby. business. The method includes:

步骤700：SMF网元获取第一信息。Step 700: The SMF network element obtains the first information.

在另一种可能的设计中，SMF网元从其他网元获取第一信息。In another possible design, the SMF network element obtains the first information from other network elements.

示例性地，一种实现方法是，SMF网元通过NEF网元向AF网元或者UDR网元发送请求消息，AF网元或者UDR网元向NEF网元发送响应消息，响应消息中携带第一信息。其中，AF网元或者UDR网元存储该第一信息。另一种实现方法是，SMF网元通过网管功能网元(operation administration and maintenance，OAM)获取第一信息。Exemplarily, an implementation method is that the SMF network element sends a request message to the AF network element or UDR network element through the NEF network element, and the AF network element or UDR network element sends a response message to the NEF network element, and the response message carries the first information. Wherein, the AF network element or the UDR network element stores the first information. Another implementation method is that the SMF network element obtains the first information through a network management function network element (operation administration and maintenance, OAM).

此外，可以理解地，第一信息中的一部分信息可以通过本地配置的方式存储在SMF网元中，第一信息中另一部分信息可以从其他网元获取。示例性地，SMF网元可以本地配置第一域名对应的第一应用的标识，SMF网元从PCF网元或者NEF网元获取第一应用所在的至少一个应用平台的位置信息，其中，PCF网元或者NEF网元存储了第一应用所在的至少一个应用平台的位置信息。In addition, it is understandable that part of the information in the first information may be stored in the SMF network element in a locally configured manner, and another part of the information in the first information may be obtained from other network elements. Exemplarily, the SMF network element may locally configure the identification of the first application corresponding to the first domain name, and the SMF network element obtains the location information of at least one application platform where the first application is located from the PCF network element or the NEF network element. The element or NEF network element stores the location information of at least one application platform where the first application is located.

此外，可以理解地，由于终端设备还未发起PDU会话建立过程，因此，一般地，SMF网元可以获取域名、应用的标识和应用所在至少一个应用平台的位置信息的对应关系，如表1所示。可以理解为，SMF网元获取多个第一信息。In addition, it is understandable that since the terminal device has not initiated the PDU session establishment process, generally, the SMF network element can obtain the corresponding relationship between the domain name, the identification of the application, and the location information of the at least one application platform where the application is located, as shown in Table 1. Show. It can be understood that the SMF network element obtains multiple pieces of first information.

步骤710：SMF网元至少根据第一信息确定第三信息。第三信息用于获取第一域名对应的第一IP地址。Step 710: The SMF network element determines third information at least according to the first information. The third information is used to obtain the first IP address corresponding to the first domain name.

以下基于第一信息包括的不同内容说明第三信息包括的具体内容。The following describes the specific content included in the third information based on the different content included in the first information.

第一种可能的形式：若第一信息还包括第一应用所在的至少一个应用平台分别对应的索引信息，第一应用所在的至少一个应用平台的位置信息可以包括第一应用所在的至少一个应用平台分别对应的DNAI，第三信息包括第一应用所在的至少一个应用平台分别对应的DNAI与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系。示例性地，第三信息可以用index与DNAI的对应关系表示。The first possible form: if the first information further includes index information corresponding to at least one application platform where the first application is located, the location information of the at least one application platform where the first application is located may include at least one application where the first application is located DNAIs respectively corresponding to the platforms, and the third information includes the corresponding relationship between the DNAIs respectively corresponding to the at least one application platform where the first application is located and the index information corresponding to the at least one application platform where the first application is located. Exemplarily, the third information may be represented by the corresponding relationship between index and DNAI.

例如，第一信息包括第一域名FQDN-A，第一域名对应的第一应用的标识APP ID-1，第一应用所在的至少一个应用平台的位置信息包括DNAI1(对应MEC-1)和DNAI2(对应MEC-2)，第一应用所在的至少一个应用平台分别对应的索引信息包括索引(Index)-1(对应MEC-1)和Index-1(对应MEC-2)。SMF网元将Index-1对应DNAI1，Index-2对应DNAI2作为第三信息。For example, the first information includes the first domain name FQDN-A, the identification APP ID-1 of the first application corresponding to the first domain name, and the location information of at least one application platform where the first application is located includes DNAI1 (corresponding to MEC-1) and DNAI2 (Corresponding to MEC-2), the index information respectively corresponding to at least one application platform where the first application is located includes index (Index)-1 (corresponding to MEC-1) and Index-1 (corresponding to MEC-2). The SMF network element regards Index-1 corresponding to DNAI1, and Index-2 corresponding to DNAI2 as the third information.

第二种可能的形式：若第一信息还包括第一应用所在的至少一个应用平台分别对应的索引信息和第一应用所在的至少一个应用平台分别对应的IP地址，第三信息包括第一应用所在的至少一个应用平台分别对应的IP地址与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系。示例性地，第三信息可以用index与ECS option的对应关系表示。A second possible form: if the first information further includes index information corresponding to at least one application platform where the first application is located and an IP address corresponding to at least one application platform where the first application is located, the third information includes the first application Correspondence between IP addresses corresponding to at least one application platform where the first application is located and index information corresponding to at least one application platform where the first application is located. Exemplarily, the third information may be represented by the corresponding relationship between index and ECS option.

例如，第一信息包括第一域名FQDN-A，第一域名对应的第一应用的标识APP ID-1，第一应用所在的至少一个应用平台的位置信息包括DNAI1(对应MEC-1)和DNAI2(对应MEC-2)，第一应用所在的至少一个应用平台分别对应的索引信息包括Index-1(对应MEC-1)和Index-1(对应MEC-2)，第一应用所在的至少一个应用平台分别对应的IP地址包括IP-1(对应DNAI1)和IP-2(对应DNAI2)。SMF网元将Index-1对应IP-1，Index-2对应IP-2作为第三信息。For example, the first information includes the first domain name FQDN-A, the identification APP ID-1 of the first application corresponding to the first domain name, and the location information of at least one application platform where the first application is located includes DNAI1 (corresponding to MEC-1) and DNAI2 (Corresponding to MEC-2), the index information corresponding to at least one application platform where the first application is located includes Index-1 (corresponding to MEC-1) and Index-1 (corresponding to MEC-2), and at least one application where the first application is located The IP addresses corresponding to the platforms include IP-1 (corresponding to DNAI1) and IP-2 (corresponding to DNAI2). The SMF network element regards Index-1 corresponding to IP-1, and Index-2 corresponding to IP-2 as the third information.

第三种可能的形式：若第一信息还包括第一应用所在的至少一个应用平台分别对应的索引信息和第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址，则第三信息包括第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系。示例性地，第三信息可以用index与local DNS server IP的对应关系表示。A third possible form: if the first information further includes index information corresponding to at least one application platform on which the first application is located and an IP address of a local DNS server corresponding to at least one application platform on which the first application is located, then the third The information includes the correspondence between the IP addresses of the local DNS servers respectively corresponding to the at least one application platform where the first application is located and the index information respectively corresponding to the at least one application platform where the first application is located. Exemplarily, the third information may be represented by the correspondence relationship between index and local DNS server IP.

例如，第一信息包括第一域名FQDN-A，第一域名对应的第一应用的标识APP ID-1，第一应用所在的至少一个应用平台的位置信息包括DNAI1(对应MEC-1)和DNAI2(对应MEC-2)，第一应用所在的至少一个应用平台分别对应的索引信息包括索Index-1(对应MEC-1)和Index-1(对应MEC-2)，第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址包括local DNS server IP-1(对应DNAI1)和local DNS server IP-2(对应DNAI2)。SMF网元将Index-1对应local DNS server IP-1，Index-2对应local DNS server IP-2作为第三信息。For example, the first information includes the first domain name FQDN-A, the identification APP ID-1 of the first application corresponding to the first domain name, and the location information of at least one application platform where the first application is located includes DNAI1 (corresponding to MEC-1) and DNAI2 (Corresponding to MEC-2), the index information corresponding to at least one application platform where the first application is located includes index-1 (corresponding to MEC-1) and Index-1 (corresponding to MEC-2), and at least one of the first application platforms is located The IP addresses of the local DNS servers corresponding to the application platforms include local DNS server IP-1 (corresponding to DNAI1) and local DNS server IP-2 (corresponding to DNAI2). The SMF network element regards Index-1 corresponding to local DNS server IP-1, and Index-2 corresponding to local DNS server IP-2 as the third information.

步骤720：SMF网元向第一UPF网元发送第一域名和第三信息。Step 720: The SMF network element sends the first domain name and third information to the first UPF network element.

应理解的是，上述步骤700～步骤720可以在终端设备发起建立PDN会话建立过程之前执行。因此，SMF网元可以将第一域名和第三信息发送至多个UPF网元，这里的多个UPF网元包括第一UPF网元。It should be understood that the foregoing steps 700 to 720 may be performed before the terminal device initiates the establishment of the PDN session establishment process. Therefore, the SMF network element can send the first domain name and the third information to multiple UPF network elements, where the multiple UPF network elements include the first UPF network element.

示例性地，SMF网元向第一UPF网元发送translation table，translation table包括第一域名和第三信息。Exemplarily, the SMF network element sends a translation table to the first UPF network element, and the translation table includes the first domain name and third information.

步骤730：SMF网元至少根据第一信息和终端设备的位置信息确定第二信息。Step 730: The SMF network element determines second information at least according to the first information and the location information of the terminal device.

第二信息用于获取第一域名对应的第一IP地址。The second information is used to obtain the first IP address corresponding to the first domain name.

示例性地，若第一应用所在的至少一个应用平台的位置信息为第一应用所在的至少一个应用平台分别对应的DNAI，SMF网元可以根据第一信息和终端设备的位置信息(例如，TAI)，从第一应用所在的至少一个应用平台中确定至少一个第一应用平台。具体地，终端设备的位置信息与第一应用所在的至少一个应用平台分别对应的DNAI之间可以存在映射关系或者对应关系，SMF网元根据终端设备的位置信息可以从第一应用所在的至少一个应用平台中确定至少一个第一应用平台。Exemplarily, if the location information of the at least one application platform where the first application is located is the DNAI corresponding to the at least one application platform where the first application is located, the SMF network element may use the first information and the location information of the terminal device (for example, TAI ), determining at least one first application platform from at least one application platform where the first application is located. Specifically, there may be a mapping relationship or a correspondence between the location information of the terminal device and the DNAI corresponding to the at least one application platform where the first application is located. The SMF network element may obtain information from at least one of the at least one application platform where the first application is located according to the location information of the terminal device. At least one first application platform is determined among the application platforms.

以下基于第一信息和第三信息包括的不同内容说明第二信息包括的具体内容。The following describes the specific content included in the second information based on the different content included in the first information and the third information.

第一种可能的形式：若第一信息还包括第一应用所在的至少一个应用平台分别对应的索引信息，第一应用所在的至少一个应用平台的位置信息可以包括第一应用所在的至少一个应用平台分别对应的DNAI，第三信息包括第一应用所在的至少一个应用平台分别对应的DNAI与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系，第二信息包括第一应用平台对应的DNAI对应的索引信息。The first possible form: if the first information further includes index information corresponding to at least one application platform where the first application is located, the location information of the at least one application platform where the first application is located may include at least one application where the first application is located. DNAI corresponding to the platforms, and the third information includes the corresponding relationship between the DNAI corresponding to the at least one application platform where the first application is located and the index information corresponding to the at least one application platform where the first application is located, and the second information includes the first application platform Index information corresponding to the corresponding DNAI.

其中，SMF网元根据第一信息和终端设备的位置信息，在至少一个应用平台中确定第一应用平台。由于应用平台与应用平台对应的DNAI存在对应关系，且应用平台对应的DNAI与应用平台对应的索引关系存在对应关系，因此，SMF网元确定第一应用平台后，可以得到第一应用平台对应的DNAI，并进一步确定第一应用平台对应的DNAI对应的索引信息作为第二信息。应理解的是，第一应用平台对应的DNAI可以用DNAI list表示。DNAI list包含至少一个DNAI。若第一应用平台的数目为多个，则DNAI list包括多个DNAI，则第一应用平台对应的DNAI对应的索引信息包括与多个DNAI分别对应的index。Wherein, the SMF network element determines the first application platform in at least one application platform according to the first information and the location information of the terminal device. Since there is a corresponding relationship between the application platform and the DNAI corresponding to the application platform, and there is a corresponding relationship between the DNAI corresponding to the application platform and the index relationship corresponding to the application platform, after the SMF network element determines the first application platform, it can get the corresponding relationship of the first application platform. DNAI, and further determine the index information corresponding to the DNAI corresponding to the first application platform as the second information. It should be understood that the DNAI corresponding to the first application platform may be represented by a DNAI list. The DNAI list contains at least one DNAI. If the number of the first application platform is multiple, the DNAI list includes multiple DNAIs, and the index information corresponding to the DNAI corresponding to the first application platform includes indexes respectively corresponding to the multiple DNAIs.

可以理解为，一个应用平台对应的DNAI可以代表该应用平台的位置信息。因此，SMF网元将第一应用平台对应的DNAI对应的索引信息作为第二信息发送给第一UPF网元，第一UPF网元可以根据第一应用平台对应的DNAI对应的索引信息和第三信息确定第一应用平台对应的DNAI，并将第一应用平台对应的DNAI添加到第一请求，得到第二请求，并向第一DNS服务器发送第二请求，以便第一DNS服务器根据第一应用平台的位置信息确定第一域名对应的第一IP地址。It can be understood that the DNAI corresponding to an application platform can represent the location information of the application platform. Therefore, the SMF network element sends the index information corresponding to the DNAI corresponding to the first application platform to the first UPF network element as the second information, and the first UPF network element can use the index information corresponding to the DNAI corresponding to the first application platform and the third The information determines the DNAI corresponding to the first application platform, and adds the DNAI corresponding to the first application platform to the first request, obtains the second request, and sends the second request to the first DNS server, so that the first DNS server according to the first application The location information of the platform determines the first IP address corresponding to the first domain name.

例如，第一信息包括第一域名FQDN-A，第一域名对应的第一应用的标识APP ID-1，第一应用所在的至少一个应用平台的位置信息包括DNAI1(对应MEC-1)和DNAI2(对应MEC-2)，第一应用所在的至少一个应用平台分别对应的索引信息包括Index-1(对应MEC-1)和Index-1(对应MEC-2)。第三信息包括Index-1对应DNAI1，Index-2对应DNAI2。SMF网元可以根据终端设备的位置信息和第一信息可以从DNAI1和DNAI2中确定DNAI1，并结合第三信息确定Index-1作为第二信息。For example, the first information includes the first domain name FQDN-A, the identification APP ID-1 of the first application corresponding to the first domain name, and the location information of at least one application platform where the first application is located includes DNAI1 (corresponding to MEC-1) and DNAI2 (Corresponding to MEC-2), the index information respectively corresponding to at least one application platform where the first application is located includes Index-1 (corresponding to MEC-1) and Index-1 (corresponding to MEC-2). The third information includes that Index-1 corresponds to DNAI1, and Index-2 corresponds to DNAI2. The SMF network element may determine DNAI1 from DNAI1 and DNAI2 according to the location information of the terminal device and the first information, and determine Index-1 as the second information in combination with the third information.

第二种可能的形式：若第一信息还包括第一应用所在的至少一个应用平台分别对应的索引信息和第一应用所在的至少一个应用平台分别对应的IP地址，第三信息包括第一应用所在的至少一个应用平台分别对应的IP地址与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系，则第二信息包括第一应用平台对应的IP地址对应的索引信息。The second possible form: if the first information further includes index information corresponding to at least one application platform where the first application is located and an IP address corresponding to at least one application platform where the first application is located, the third information includes the first application Correspondence between the IP address corresponding to the at least one application platform where the first application is located and the index information corresponding to the at least one application platform where the first application is located, and the second information includes the index information corresponding to the IP address corresponding to the first application platform.

其中，SMF网元根据第一信息和终端设备的位置信息，在至少一个应用平台中确定第一应用平台，进一步地，由于应用平台与应用平台对应的IP地址存在对应关系，且应用平台对应的DNAI与应用平台对应的索引关系存在对应关系，因此，在确定第一应用平台后，SMF网元根据第一应用所在的至少一个应用平台分别对应的IP地址确定第一应用平台对应的IP地址，将第一应用平台对应的IP地址对应的索引信息作为第二信息。第一应用平台对应的IP地址可以用ECS option list表示。ECS option list包含至少一个ECS option。若第一应用平台的数目为多个，则ECS option list包括多个ECS option，每一个ECS option包括一个IP地址，其中，ECS option中包含的IP地址是应用平台对应IP地址，对该IP地址的描述可以参考前面的描述，重复之处不在赘述。则第一应用平台对应的IP地址对应的索引信息包括与多个ECS option分别对应的index。Among them, the SMF network element determines the first application platform in at least one application platform according to the first information and the location information of the terminal device. Further, since the application platform has a corresponding relationship with the IP address corresponding to the application platform, and the application platform corresponds to There is a corresponding relationship between the index relationship between DNAI and the application platform. Therefore, after determining the first application platform, the SMF network element determines the IP address corresponding to the first application platform according to the respective IP addresses of at least one application platform where the first application is located. The index information corresponding to the IP address corresponding to the first application platform is used as the second information. The IP address corresponding to the first application platform can be represented by ECS option list. The ECS option list contains at least one ECS option. If the number of the first application platform is multiple, the ECS option list includes multiple ECS options, and each ECS option includes an IP address. The IP address contained in the ECS option is the IP address corresponding to the application platform. The description of can refer to the previous description, and the repetition will not be repeated. Then, the index information corresponding to the IP address corresponding to the first application platform includes indexes corresponding to multiple ECS options, respectively.

可以理解为，一个应用平台对应的IP地址可以代表该应用平台的位置信息，因此，SMF网元将第一应用平台对应的IP地址对应的索引信息作为第二信息发送给第一UPF网元，第一UPF网元可以根据第一应用平台对应的IP地址对应的索引信息和第三信息确定第一应用平台对应的IP地址，将第一应用平台对应的IP地址添加到第一请求，得到第二请求，并向第一DNS服务器发送第二请求，以便第一DNS服务器根据第一应用平台的位置信息确定第一域名对应的第一IP地址。It can be understood that the IP address corresponding to an application platform can represent the location information of the application platform. Therefore, the SMF network element sends the index information corresponding to the IP address corresponding to the first application platform as the second information to the first UPF network element. The first UPF network element may determine the IP address corresponding to the first application platform according to the index information corresponding to the IP address corresponding to the first application platform and the third information, and add the IP address corresponding to the first application platform to the first request to obtain the first request. Second request, and send a second request to the first DNS server, so that the first DNS server determines the first IP address corresponding to the first domain name according to the location information of the first application platform.

例如，第一信息包括第一域名FQDN-A，第一域名对应的第一应用的标识APP ID-1，第一应用所在的至少一个应用平台的位置信息包括DNAI1(对应MEC-1)和DNAI2(对应MEC-2)，第一应用所在的至少一个应用平台分别对应的IP地址包括IP-1(对应DNAI1)和IP-2(对应DNAI2)，第三信息包括Index-1对应IP-1，Index-2对应IP-2。SMF网元可以根据终端设备的位置信息和第一信息可以从DNAI1和DNAI2中确定DNAI1，并根据DNAI1确定IP-1，结合第三信息将Index-1作为第二信息。For example, the first information includes the first domain name FQDN-A, the identification APP ID-1 of the first application corresponding to the first domain name, and the location information of at least one application platform where the first application is located includes DNAI1 (corresponding to MEC-1) and DNAI2 (Corresponding to MEC-2), the IP addresses corresponding to at least one application platform where the first application is located include IP-1 (corresponding to DNAI1) and IP-2 (corresponding to DNAI2), and the third information includes Index-1 corresponding to IP-1, Index-2 corresponds to IP-2. The SMF network element can determine DNAI1 from DNAI1 and DNAI2 according to the location information of the terminal device and the first information, and determine IP-1 according to DNAI1, and use Index-1 as the second information in combination with the third information.

第三种可能的形式：若第一信息还包括第一应用所在的至少一个应用平台分别对应的索引信息和第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址，第三信息包括第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系，则第二信息包括第一本地DNS服务器的IP地址对应的索引信息，第一本地DNS服务器为第一应用平台提供服务。A third possible form: if the first information further includes index information corresponding to at least one application platform where the first application is located and the IP address of a local DNS server respectively corresponding to the at least one application platform where the first application is located, the third information Including the correspondence between the IP addresses of the local DNS servers respectively corresponding to the at least one application platform where the first application is located and the index information respectively corresponding to the at least one application platform where the first application is located, the second information includes the IP of the first local DNS server For index information corresponding to the address, the first local DNS server provides services for the first application platform.

其中，SMF网元根据第一信息和终端设备的位置信息，在至少一个应用平台中确定第一应用平台，进一步地，由于应用平台与应用平台对应的本地DNS服务器的IP地址存在对应关系，且应用平台对应的本地DNS服务器的IP地址与应用平台对应的索引关系存在对应关系，因此，在确定第一应用平台后，SMF网元根据第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址确定第一本地DNS服务器的IP地址，将第一本地DNS服务器的IP地址对应的索引信息作为第二信息。Wherein, the SMF network element determines the first application platform in at least one application platform according to the first information and the location information of the terminal device. Further, since the application platform has a corresponding relationship with the IP address of the local DNS server corresponding to the application platform, and There is a corresponding relationship between the IP address of the local DNS server corresponding to the application platform and the index relationship corresponding to the application platform. Therefore, after the first application platform is determined, the SMF network element corresponds to the local DNS server respectively corresponding to at least one application platform where the first application is located. The IP address of determines the IP address of the first local DNS server, and the index information corresponding to the IP address of the first local DNS server is used as the second information.

在本申请中，第一应用平台可以理解为本地应用平台或者MEC平台，那么服务第一应用平台的本地DNS服务器称为第一本地DNS服务器。此外，如果第一应用所在的至少一个应用平台包括多个本地应用平台或者多个MEC平台，那么服务该本地应用平台或者该MEC平台服务的本地DNS服务器可能存在多个。可以理解为，若第一应用平台的数目为多个，且多个第一应用平台分别对应的本地DNS服务器也是多个，则在这种情况下，SMF网元可以基于本地策略选择一个本地DNS服务器作为第一本地DNS服务器。在一种实现方式中，SMF网元基于多个本地DNS服务器中每一个本地DNS服务器的负载情况，将负载较轻的本地DNS服务器作为第一本地DNS服务器。在另一种实现方式中，SMF网元基于多个本地DNS服务器中每一个本地DNS服务器支持的域名查询列表，将支持的域名查询列表较多的本地DNS服务器作为第一本地DNS服务器。In this application, the first application platform can be understood as a local application platform or an MEC platform, and the local DNS server serving the first application platform is called the first local DNS server. In addition, if at least one application platform where the first application is located includes multiple local application platforms or multiple MEC platforms, there may be multiple local DNS servers that serve the local application platform or the MEC platform. It can be understood that if the number of first application platforms is multiple, and the local DNS servers corresponding to the multiple first application platforms are also multiple, in this case, the SMF network element can select a local DNS based on the local policy. The server serves as the first local DNS server. In an implementation manner, the SMF network element uses the local DNS server with a lighter load as the first local DNS server based on the load condition of each local DNS server among the multiple local DNS servers. In another implementation manner, the SMF network element uses the local DNS server with more supported domain name query lists as the first local DNS server based on the domain name query list supported by each of the multiple local DNS servers.

因此，SMF网元将第一本地DNS服务器的IP地址对应的索引信息作为第二信息发送给第一UPF网元，第一UPF网元可以根据第一本地DNS服务器的IP地址对应的索引信息和第三信息确定第一本地DNS服务器的IP地址，第一UPF网元将第一请求的目标地址修改为第一本地DNS服务器的IP地址，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为第一本地DNS服务器。Therefore, the SMF network element sends the index information corresponding to the IP address of the first local DNS server as the second information to the first UPF network element, and the first UPF network element can use the index information corresponding to the IP address of the first local DNS server and The third information determines the IP address of the first local DNS server. The first UPF network element modifies the target address of the first request to the IP address of the first local DNS server, obtains the second request, and sends the second request to the first DNS server, the first DNS server is the first local DNS server.

例如，第一信息包括第一域名FQDN-A，第一域名对应的第一应用的标识APP ID-1，第一应用所在的至少一个应用平台的位置信息包括DNAI1(对应MEC-1)和DNAI2(对应MEC-2)，第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址包括local DNS server IP-1(对应DNAI1)和local DNS server IP-2(对应DNAI2)。第三信息包括Index-1对应local DNS server IP-1，Index-2对应local DNS server IP-2。SMF网元可以根据终端设备的位置信息和第一信息可以从DNAI1和DNAI2中确定DNAI1，并根据DNAI1确定local DNS server IP-1，结合第三信息将Index-1作为第二信息。For example, the first information includes the first domain name FQDN-A, the identification APP ID-1 of the first application corresponding to the first domain name, and the location information of at least one application platform where the first application is located includes DNAI1 (corresponding to MEC-1) and DNAI2 (Corresponding to MEC-2), the IP addresses of the local DNS servers respectively corresponding to at least one application platform where the first application is located include local DNS server IP-1 (corresponding to DNAI1) and local DNS server IP-2 (corresponding to DNAI2). The third information includes that Index-1 corresponds to local DNS server IP-1, and Index-2 corresponds to local DNS server IP-2. The SMF network element can determine DNAI1 from DNAI1 and DNAI2 according to the location information of the terminal device and the first information, and determine the local DNS server IP-1 according to DNAI1, and use Index-1 as the second information in combination with the third information.

基于以上相同的构思，SMF网元获取域名、应用的标识和应用所在至少一个应用平台的位置信息的对应关系。其中，域名、应用的标识和应用所在至少一个应用平台的位置信息的对应关系可以理解为整个网络中部署的全部应用的标识、与全部应用中的每个应用对应的域名以及全部应用中的每个应用所在至少一个应用平台的位置信息的对应关系(以下简称为第一种类型的对应关系)。SMF网元获取第一种类型的对应关系的方法可以参考步骤700，重复之处不在赘述。针对上述第二信息和第三信息可能的形式，进一步可以扩展以下三种可能的设计：Based on the same concept as above, the SMF network element obtains the corresponding relationship between the domain name, the identification of the application, and the location information of at least one application platform where the application is located. Among them, the correspondence between the domain name, the application identifier, and the location information of at least one application platform where the application is located can be understood as the identifiers of all applications deployed in the entire network, the domain names corresponding to each of all applications, and each of all applications. The corresponding relationship of the location information of at least one application platform where each application is located (hereinafter referred to as the first type of corresponding relationship). For the method for the SMF network element to obtain the corresponding relationship of the first type, reference may be made to step 700, and the repetition is not repeated here. In view of the possible forms of the above-mentioned second information and third information, the following three possible designs can be further expanded:

第一种可能的设计：The first possible design:

在终端设备发起PDU会话建立过程之前，SMF网元根据第一种类型的对应关系以及应用平台的索引信息和应用平台的位置信息的对应关系，确定域名、与域名对应的应用所在至少一个应用平台的位置信息、与域名对应的应用所在至少一个应用平台的索引信息的对应关系(以下简称为第一对应关系)，SMF网元将第一对应关系发送至第一UPF网元。Before the terminal device initiates the PDU session establishment process, the SMF network element determines the domain name and at least one application platform where the application corresponding to the domain name is based on the first type of correspondence and the correspondence between the index information of the application platform and the location information of the application platform. The SMF network element sends the first corresponding relationship to the first UPF network element.

在终端设备发起PDU会话建立过程中，SMF网元获取终端设备签约的多个应用的标识。其中，终端设备签约的多个应用的标识可以采用以下方式获得：在终端设备发起PDU会话建立过程中，在SMF网元调用PCF网元请求从PCF网元获取该PDU会话相关的策略信息后，PCF网元调用UDR的服务化操作请求，从UDR获取该终端设备签约的多个应用相关的信息，其中，终端设备签约的多个应用相关的信息包括终端设备签约的多个应用的标识。In the process of establishing a PDU session initiated by the terminal device, the SMF network element obtains the identities of multiple applications subscribed by the terminal device. Among them, the identities of multiple applications signed by the terminal device can be obtained in the following manner: in the process of initiating the establishment of a PDU session by the terminal device, after the SMF network element calls the PCF network element to request the policy information related to the PDU session from the PCF network element, The PCF network element invokes the service operation request of the UDR, and obtains information related to multiple applications subscribed by the terminal device from the UDR. The information related to multiple applications subscribed by the terminal device includes the identities of multiple applications subscribed by the terminal device.

进一步地，SMF网元根据终端设备的位置信息，多个域名，以及第一种类型的对应关系，确定多个域名中每个域名对应的DNAI list，其中，多个域名是指与终端设备签约的多个应用中的每个应用对应的域名。SMF网元根据第一对应关系和多个域名中每个域名对应的DNAI list获得多个域名分别对应的DNAI list中的每个DNAI对应的index，将多个域名分别对应的DNAI list中的每个DNAI对应的index发送至第一UPF网元。Further, the SMF network element determines the DNAI list corresponding to each of the multiple domain names according to the location information of the terminal device, multiple domain names, and the corresponding relationship of the first type, where multiple domain names refer to the contract with the terminal device The domain name corresponding to each of the multiple applications. The SMF network element obtains the index corresponding to each DNAI in the DNAI list corresponding to the multiple domain names according to the first correspondence and the DNAI list corresponding to each domain name in the multiple domain names. The index corresponding to each DNAI is sent to the first UPF network element.

示例性地，在UE发起PDU会话建立过程之前，SMF网元根据表1和应用平台的索引信息和应用平台的位置信息的对应关系，确定表10，将表10发送至第一UPF网元。在UE发起PDU会话建立过程中，UE签约的多个应用相关的信息包括APP-1和APP-2。其中，APP-1对应FQDN-A，APP-2对应FQDN-B。SMF网元根据UE的位置信息(TAI)和表1，从FQDN-A对应的DNAI1和DNAI2中确定DNAI1，从FQDN-B对应的DNAI2 和DNAI3中确定DNAI2和DNAI3，即分别确定每个域名对应的DNAI list，如表11所示。SMF网元根据表10和表11得到表12，进一步地，SMF网元根据表12得到表13，将表13发送至第一UPF网元。Exemplarily, before the UE initiates the PDU session establishment process, the SMF network element determines Table 10 according to the correspondence between Table 1 and the index information of the application platform and the location information of the application platform, and sends Table 10 to the first UPF network element. In the process of establishing a PDU session initiated by the UE, multiple application-related information subscribed by the UE includes APP-1 and APP-2. Among them, APP-1 corresponds to FQDN-A, and APP-2 corresponds to FQDN-B. The SMF network element determines DNAI1 from DNAI1 and DNAI2 corresponding to FQDN-A according to the location information (TAI) of the UE and Table 1, and determines DNAI2 and DNAI3 from DNAI2 and DNAI3 corresponding to FQDN-B, which means that each domain name corresponds to each domain name. The DNAI list is shown in Table 11. The SMF network element obtains Table 12 according to Table 10 and Table 11. Further, the SMF network element obtains Table 13 according to Table 12, and sends Table 13 to the first UPF network element.

表10Table 10

表11Table 11

表12Table 12

表13Table 13

第二种可能的设计：The second possible design:

在终端设备发起PDU会话建立过程之前，SMF网元根据第一种类型的对应关系以及应用平台的索引信息和应用平台的位置信息的对应关系，应用平台的IP地址和应用平台的位置信息的对应关系，确定域名、与域名对应的应用所在至少一个应用平台的IP地址、与域名对应的应用所在至少一个应用平台的索引信息的对应关系(以下简称为第二对应关系)，SMF网元将第二对应关系发送至第一UPF网元。Before the terminal device initiates the PDU session establishment process, the SMF network element corresponds to the first type of correspondence and the correspondence between the index information of the application platform and the location information of the application platform, and the correspondence between the IP address of the application platform and the location information of the application platform. Relationship, determine the correspondence relationship between the domain name, the IP address of at least one application platform where the application corresponding to the domain name is located, and the index information of at least one application platform where the application corresponding to the domain name is located (hereinafter referred to as the second correspondence relationship). The two correspondences are sent to the first UPF network element.

在终端设备发起PDU会话建立过程中，SMF网元获取终端设备签约的多个应用的标识。SMF网元获取终端设备签约的多个应用的标识的方法可以参考第一种可能的设计，此处不再赘述。进一步地，SMF网元根据终端设备的位置信息，多个域名，以及第一种类型的对应关系，确定多个域名中每个域名对应的DNAI list，其中，多个域名是指与终端设备签约的多个应用中的每个应用对应的域名。SMF网元进一步根据应用平台的IP地址和应用平台的DNAI的对应关系和第二对应关系获得多个域名分别对应的ECS option list中的每个ECS option对应的索引信息，将多个域名分别对应的ECS option list中的每个ECS option对应的索引信息发送至第一UPF网元。In the process of establishing a PDU session initiated by the terminal device, the SMF network element obtains the identities of multiple applications subscribed by the terminal device. The method for the SMF network element to obtain the identities of the multiple applications subscribed by the terminal device can refer to the first possible design, which will not be repeated here. Further, the SMF network element determines the DNAI list corresponding to each of the multiple domain names according to the location information of the terminal device, multiple domain names, and the corresponding relationship of the first type, where multiple domain names refer to the contract with the terminal device The domain name corresponding to each of the multiple applications. The SMF network element further obtains the index information corresponding to each ECS option in the ECS option list corresponding to multiple domain names according to the correspondence between the IP address of the application platform and the DNAI of the application platform and the second correspondence, and corresponds to the multiple domain names. The index information corresponding to each ECS option in the ECS option list is sent to the first UPF network element.

示例性地，在UE发起PDU会话建立过程之前，SMF网元根据表1和应用平台的IP地址和应用平台的DNAI的对应关系(如表13所示)，确定表14，并进一步根据应用平台的索引信息和应用平台的位置信息的对应关系，确定表15，根据表15确定表16，将表16发送至第一UPF网元。在UE发起PDU会话建立过程中，UE签约的多个应用相关的信息包括APP-1和APP-2。其中，APP-1对应FQDN-A，APP-2对应FQDN-B。SMF网元根据UE的位置信息和表1，从FQDN-A对应的DNAI1和DNAI2中确定DNAI1，从FQDN-B对应的DNAI2和DNAI3中确定DNAI2和DNAI3，如表11所示。SMF网元根据表15和表11得到表17，进一步地，SMF网元根据表17得到表18，将表18发送至第一UPF网元。Exemplarily, before the UE initiates the PDU session establishment process, the SMF network element determines Table 14 according to Table 1 and the correspondence between the IP address of the application platform and the DNAI of the application platform (as shown in Table 13), and further according to the application platform The corresponding relationship between the index information and the location information of the application platform is determined in Table 15, and Table 16 is determined according to Table 15, and Table 16 is sent to the first UPF network element. In the process of establishing a PDU session initiated by the UE, multiple application-related information subscribed by the UE includes APP-1 and APP-2. Among them, APP-1 corresponds to FQDN-A, and APP-2 corresponds to FQDN-B. The SMF network element determines DNAI1 from DNAI1 and DNAI2 corresponding to FQDN-A according to the location information of the UE and Table 1, and determines DNAI2 and DNAI3 from DNAI2 and DNAI3 corresponding to FQDN-B, as shown in Table 11. The SMF network element obtains Table 17 according to Table 15 and Table 11. Further, the SMF network element obtains Table 18 according to Table 17, and sends Table 18 to the first UPF network element.

表13Table 13

表14Table 14

表15Table 15

表16Table 16

表17Table 17

表18Table 18

第三种可能的设计：The third possible design:

在终端设备发起PDU会话建立过程之前，SMF网元根据第一种类型的对应关系以及应用平台的索引信息和应用平台的位置信息的对应关系，应用平台的本地DNS服务器的IP地址和应用平台的位置信息的对应关系，确定域名、与域名对应的应用所在至少一个应用平台的本地DNS服务器的IP地址、与域名对应的应用所在至少一个应用平台的索引信息的对应关系(以下简称为第三对应关系)，SMF网元将第三对应关系发送至第一UPF网元。Before the terminal device initiates the PDU session establishment process, the SMF network element uses the first type of correspondence and the correspondence between the index information of the application platform and the location information of the application platform, the IP address of the local DNS server of the application platform, and the application platform’s corresponding relationship. Correspondence of location information, determine the correspondence between the domain name, the IP address of the local DNS server of at least one application platform where the application corresponding to the domain name is located, and the index information of the at least one application platform where the application corresponding to the domain name is located (hereinafter referred to as the third correspondence) Relationship), the SMF network element sends the third correspondence to the first UPF network element.

在终端设备发起PDU会话建立过程中，SMF网元获取终端设备签约的多个应用的标识。SMF网元获取终端设备签约的多个应用的标识的方法可以参考第一种可能的设计，此处不再赘述。进一步地，SMF网元根据终端设备的位置信息，多个域名，以及第一种类型的对应关系，确定多个域名中每个域名对应的DNAI list，其中，多个域名是指与终端设备签约的多个应用中的每个应用对应的域名。SMF网元进一步根据应用平台的本地DNS服务器的IP地址和应用平台的位置信息的对应关系和第三对应关系获得多个域名分别对应的第一本地DNS服务器的IP地址对应的索引信息，将多个域名分别对应的第一本地DNS服务器的IP地址对应的索引信息发送至第一UPF网元。In the process of establishing a PDU session initiated by the terminal device, the SMF network element obtains the identities of multiple applications subscribed by the terminal device. The method for the SMF network element to obtain the identities of the multiple applications subscribed by the terminal device can refer to the first possible design, which will not be repeated here. Further, the SMF network element determines the DNAI list corresponding to each of the multiple domain names according to the location information of the terminal device, multiple domain names, and the corresponding relationship of the first type, where multiple domain names refer to the contract with the terminal device The domain name corresponding to each of the multiple applications. The SMF network element further obtains the index information corresponding to the IP address of the first local DNS server corresponding to the multiple domain names according to the correspondence between the IP address of the local DNS server of the application platform and the location information of the application platform and the third correspondence. The index information corresponding to the IP address of the first local DNS server corresponding to each domain name is sent to the first UPF network element.

示例性地，在UE发起PDU会话建立过程之前，SMF网元根据表1和应用平台的本地DNS服务器的IP地址和应用平台的位置信息的对应关系(如表19所示)，确定表20，并进一步根据应用平台的索引信息和应用平台的位置信息的对应关系，确定表21，根据表21确定表22，将表22发送至第一UPF网元。在UE发起PDU会话建立过程中，UE签约的应用相关的信息包括APP-1和APP-2。其中，APP-1对应FQDN-A，APP-2对应FQDN-B。SMF网元根据UE的位置信息和表1，从FQDN-A对应的DNAI1和DNAI2中确定DNAI1，从FQDN-B对应的DNAI2和DNAI3中确定DNAI2和DNAI3，如表11所示。SMF网元根据表21和表11得到表23，进一步地，SMF网元根据表23得到表24，将表24发送至第一UPF网元。Exemplarily, before the UE initiates the PDU session establishment process, the SMF network element determines Table 20 according to Table 1 and the correspondence between the IP address of the local DNS server of the application platform and the location information of the application platform (as shown in Table 19). Furthermore, according to the corresponding relationship between the index information of the application platform and the location information of the application platform, the table 21 is determined, the table 22 is determined according to the table 21, and the table 22 is sent to the first UPF network element. When the UE initiates the establishment of a PDU session, the information related to the application subscribed by the UE includes APP-1 and APP-2. Among them, APP-1 corresponds to FQDN-A, and APP-2 corresponds to FQDN-B. The SMF network element determines DNAI1 from DNAI1 and DNAI2 corresponding to FQDN-A according to the location information of the UE and Table 1, and determines DNAI2 and DNAI3 from DNAI2 and DNAI3 corresponding to FQDN-B, as shown in Table 11. The SMF network element obtains Table 23 according to Table 21 and Table 11. Further, the SMF network element obtains Table 24 according to Table 23, and sends the table 24 to the first UPF network element.

表19Table 19

表20Table 20

表21Table 21

表22Table 22

表23Table 23

表24Table 24

步骤740：SMF网元向第一UPF网元发送第一域名和第二信息。Step 740: The SMF network element sends the first domain name and second information to the first UPF network element.

应理解的是，上述步骤730～步骤740可以在终端设备发起建立PDN会话建立过程中执行。在PDN会话建立过程中，SMF网元已根据DNN和S-NSSAI等参数选择第一UPF网元作为终端设备的PDU会话的锚点，因此，SMF网元向第一UPF网元发送第一域名和第二信息，可以选择不向其他UPF网元发送第一域名和第二信息。示例性地，SMF网元向第一UPF网元发送N4会话建立请求消息，N4会话建立请求消息中需要携带translation table。translation table包括第一域名和第二信息。It should be understood that the foregoing steps 730 to 740 may be executed during the establishment of the PDN session initiated by the terminal device. During the establishment of the PDN session, the SMF network element has selected the first UPF network element as the anchor point of the PDU session of the terminal device according to parameters such as DNN and S-NSSAI. Therefore, the SMF network element sends the first domain name to the first UPF network element And the second information, you can choose not to send the first domain name and the second information to other UPF network elements. Exemplarily, the SMF network element sends an N4 session establishment request message to the first UPF network element, and the N4 session establishment request message needs to carry a translation table. The translation table includes the first domain name and the second information.

步骤750：第一UPF网元接收来自于终端设备的第一请求，第一请求包括第一域名。Step 750: The first UPF network element receives a first request from the terminal device, where the first request includes the first domain name.

步骤760：第一UPF网元根据第二信息和第三信息确定第二请求，并向第一DNS服务器发送第二请求，第二请求用于在终端设备位于第一位置时获取第一域名对应的第一IP地址。其中，终端设备的位置信息指示终端设备处于第一位置。Step 760: The first UPF network element determines the second request based on the second information and the third information, and sends the second request to the first DNS server. The second request is used to obtain the first domain name correspondence when the terminal device is located at the first location. The first IP address. Wherein, the location information of the terminal device indicates that the terminal device is in the first position.

应理解的是，基于上述第二信息和第三信息的不同形式，第一UPF网元根据第二信息和第三信息确定第二请求，并向第一DNS服务器发送第二请求也可以包括以下三种情况：It should be understood that, based on the above-mentioned different forms of the second information and the third information, the first UPF network element determines the second request according to the second information and the third information, and sends the second request to the first DNS server may also include the following three conditions:

情况1：第三信息包括第一应用所在的至少一个应用平台分别对应的DNAI与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系，第二信息包括第一应用平台对应的DNAI对应的索引信息。Case 1: The third information includes the corresponding relationship between the DNAI corresponding to the at least one application platform where the first application is located and the index information corresponding to the at least one application platform where the first application is located, and the second information includes the DNAI corresponding to the first application platform. Corresponding index information.

第一UPF网元根据第一应用所在的至少一个应用平台分别对应的DNAI与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系和第一应用平台对应的DNAI对应的索引信息，确定第一应用平台对应的DNAI，将第一应用平台对应的DNAI添加至第一请求，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为集中DNS服务器。The first UPF network element corresponds to the index information corresponding to the DNAI corresponding to the at least one application platform where the first application is located and the index information corresponding to the at least one application platform where the first application is located, and the index information corresponding to the DNAI corresponding to the first application platform. Determine the DNAI corresponding to the first application platform, add the DNAI corresponding to the first application platform to the first request, obtain the second request, and send the second request to the first DNS server, which is a centralized DNS server.

例如，与FQDN-A对应的第三信息包括Index-1对应DNAI1，Index-2对应DNAI2。与FQDN-A对应的第二信息包括Index-1。第一UPF网元接收来自于UE的第一请求，第一请求包括FQDN-A，则第一UPF网元查询FQDN-A，确定存在与FQDN-A对应的第二信息和第三信息，并进一步根据与FQDN-A对应的第二信息和第三信息确定DNAI1，将DNAI1添加至第一请求，获得第二请求，将第二请求发送至第一DNS服务器，第一DNS服务器为集中DNS服务器。For example, the third information corresponding to FQDN-A includes Index-1 corresponding to DNAI1 and Index-2 corresponding to DNAI2. The second information corresponding to FQDN-A includes Index-1. The first UPF network element receives the first request from the UE, and the first request includes FQDN-A, then the first UPF network element queries FQDN-A, determines that there are second information and third information corresponding to FQDN-A, and Further determine DNAI1 according to the second and third information corresponding to FQDN-A, add DNAI1 to the first request, obtain the second request, and send the second request to the first DNS server, which is a centralized DNS server .

情况2：第三信息包括第一应用所在的至少一个应用平台分别对应的IP地址与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系，第二信息包括第一应用平台对应的IP地址对应的索引信息。Case 2: The third information includes the corresponding relationship between the IP address corresponding to the at least one application platform where the first application is located and the index information corresponding to the at least one application platform where the first application is located, and the second information includes the corresponding relationship between the first application platform and the corresponding IP address. Index information corresponding to the IP address.

第一UPF网元根据第一应用所在的至少一个应用平台分别对应的IP地址与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系和第一应用平台对应的IP地址对应的索引信息，确定第一应用平台对应的IP地址，将第一应用平台对应的IP地址添加至第一请求，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为集中DNS服务器。The first UPF network element corresponds to the index information corresponding to the at least one application platform where the first application is located and the corresponding index information corresponding to the at least one application platform where the first application is located, and the index corresponding to the IP address corresponding to the first application platform. Information, determine the IP address corresponding to the first application platform, add the IP address corresponding to the first application platform to the first request, obtain the second request, and send the second request to the first DNS server, the first DNS server is centralized DNS server.

例如，与FQDN-A对应的第三信息包括Index-1对应IP-1，Index-2对应IP-2。与FQDN-A对应的第二信息包括Index-1。第一UPF网元接收来自于UE的第一请求，第一请求包括FQDN-A，则第一UPF网元查询FQDN-A，确定存在与FQDN-A对应的第二信息和与FQDN-A对应的第三信息，并进一步根据与FQDN-A对应的第二信息和与FQDN-A对应的第三信息确定IP-1，将IP-1添加至第一请求，获得第二请求，将第二请求发送至第一DNS服务器，第一DNS服务器为集中DNS服务器。For example, the third information corresponding to FQDN-A includes Index-1 corresponding to IP-1 and Index-2 corresponding to IP-2. The second information corresponding to FQDN-A includes Index-1. The first UPF network element receives the first request from the UE, and the first request includes FQDN-A, then the first UPF network element queries FQDN-A, and determines that there is second information corresponding to FQDN-A and corresponding to FQDN-A And further determine IP-1 according to the second information corresponding to FQDN-A and the third information corresponding to FQDN-A, add IP-1 to the first request, obtain the second request, and add the second The request is sent to the first DNS server, which is a centralized DNS server.

情况3：第三信息包括第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系，第二信息包括第一本地DNS服务器的IP地址对应的索引信息，第一本地DNS服务器为第一应用平台提供服务。Case 3: The third information includes the correspondence between the IP address of the local DNS server corresponding to the at least one application platform where the first application is located and the index information corresponding to the at least one application platform where the first application is located, and the second information includes the first Index information corresponding to the IP address of the local DNS server, and the first local DNS server provides services for the first application platform.

第一UPF网元可以根据第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址与第一应用所在的至少一个应用平台分别对应的索引信息的对应关系和第一本地DNS服务器的IP地址对应的索引信息确定第一本地DNS服务器的IP地址，将第一请求的目标地址修改为第一本地DNS服务器的IP地址，获得第二请求，并将第二请求发送至第一DNS服务器，第一DNS服务器为第一本地DNS服务器。The first UPF network element may be based on the correspondence between the IP address of the local DNS server corresponding to the at least one application platform where the first application is located and the index information corresponding to the at least one application platform where the first application is located, and the value of the first local DNS server. The index information corresponding to the IP address determines the IP address of the first local DNS server, modifies the target address of the first request to the IP address of the first local DNS server, obtains the second request, and sends the second request to the first DNS server , The first DNS server is the first local DNS server.

例如，与FQDN-A对应的第三信息包括Index-1对应local DNS server IP-1，Index-2对应local DNS server IP-2。与FQDN-A对应的第二信息包括Index-1。第一UPF网元接收来自于UE的第一请求，第一请求包括FQDN-A，则第一UPF网元查询FQDN-A，确定存在与FQDN-A对应的第二信息和与FQDN-A对应的第三信息，并进一步根据与FQDN-A对应的第二信息和与FQDN-A对应的第三信息确定local DNS server IP-1，将第一请求的目标地址修改为与FQDN-A对应的local DNS server IP-1，获得第二请求，并将第二请求发送至local DNS server IP-1对应的本地DNS服务器。For example, the third information corresponding to FQDN-A includes Index-1 corresponding to local DNS server IP-1, and Index-2 corresponding to local DNS server IP-2. The second information corresponding to FQDN-A includes Index-1. The first UPF network element receives the first request from the UE, and the first request includes FQDN-A, then the first UPF network element queries FQDN-A, and determines that there is second information corresponding to FQDN-A and corresponding to FQDN-A And further determine the local DNS server IP-1 according to the second information corresponding to FQDN-A and the third information corresponding to FQDN-A, and modify the target address of the first request to correspond to FQDN-A local DNS server IP-1, obtains the second request, and sends the second request to the local DNS server corresponding to local DNS server IP-1.

此外，在一种可能的设计中，SMF网元还向第一UPF网元发送第一指示信息，第一指示信息用于指示第一UPF网元在接收到来自于终端设备的第一请求且第一请求包括第一域名时，根据第二信息和第三信息确定第二请求，并将第二请求发送至第一DNS服务器。In addition, in a possible design, the SMF network element also sends first indication information to the first UPF network element, where the first indication information is used to indicate that the first UPF network element is receiving the first request from the terminal device and When the first request includes the first domain name, the second request is determined according to the second information and the third information, and the second request is sent to the first DNS server.

示例性地，第一UPF网元根据第二信息和第三信息确定第一应用平台对应的IP地址，第一应用平台对应的IP地址用ECS option list表示，若第一应用平台的数目为多个，则ECS option list包括多个IP地址，DNS服务器可以根据本地策略从ECS option list中确定目标ECS option和目标应用平台。在一种实现方式中，DNS服务器基于ECS option list中包括多个IP地址确定多个应用平台，并进一步基于多个应用平台的负载情况，将负载较轻的应用平台作为目标应用平台，并将包括该目标应用平台对应的IP地址的ECS option作为目标ECS option。DNS服务器将目标应用平台对应的DNAI、或目标应用平台对应的IP地址发送给第一UPF网元。其中，目标应用平台为第二应用平台。Exemplarily, the first UPF network element determines the IP address corresponding to the first application platform according to the second information and the third information, and the IP address corresponding to the first application platform is represented by the ECS option list. If the number of the first application platform is more If the ECS option list includes multiple IP addresses, the DNS server can determine the target ECS option and target application platform from the ECS option list according to the local policy. In one implementation, the DNS server determines multiple application platforms based on the multiple IP addresses included in the ECS option list, and further based on the load conditions of multiple application platforms, the application platform with a lighter load is used as the target application platform, and The ECS option that includes the IP address corresponding to the target application platform is used as the target ECS option. The DNS server sends the DNAI corresponding to the target application platform or the IP address corresponding to the target application platform to the first UPF network element. Among them, the target application platform is the second application platform.

在第一UPF网元将第二请求发送至第一DNS服务器之后，第一UPF接收来自于第一DNS服务器的针对第一请求的响应消息，该响应消息包括第一IP地址、第一域名对应的DNS缓存记录的存留时间(time to live，TTL)。此外，该响应消息还可以包括第一应用所在的第二应用平台对应的DNAI或第一应用所在的第二应用平台对应的IP地址。第一UPF保存该响应消息，并向SMF网元发送第四信息。第四信息包括第一应用所在的第二应用平台对应的DNAI或者第一应用所在的第二应用平台对应的IP地址、第一IP地址中的至少一种。After the first UPF network element sends the second request to the first DNS server, the first UPF receives a response message from the first DNS server for the first request, and the response message includes the first IP address and the corresponding first domain name. The time to live (TTL) of the DNS cache record. In addition, the response message may also include the DNAI corresponding to the second application platform where the first application is located or the IP address corresponding to the second application platform where the first application is located. The first UPF saves the response message, and sends the fourth message to the SMF network element. The fourth information includes at least one of DNAI corresponding to the second application platform where the first application is located, or an IP address corresponding to the second application platform where the first application is located, and the first IP address.

综上所述，SMF网元获取第一信息，根据第一信息确定第三信息，向第一UPF网元发送第一域名和第三信息。进一步地，SMF网元还至少根据UE的位置信息和第一信息确定第二信息，并向第一UPF网元发送第一域名和第二信息。第一UPF网元在接收来自于终端设备的第一请求且第一请求包括第一域名时，第一UPF网元根据第二信息和第三信息确定第二请求，并向第一DNS服务器发送第二请求，以便第一DNS服务器获取的第一域名对应的第一IP地址。当终端设备在终端设备的位置信息所指示的位置采用第一IP地址访问第一域名时，能够实现终端设备就近访问本地业务，可以降低访问业务的时延，进而可以提高通信效率。In summary, the SMF network element obtains the first information, determines the third information according to the first information, and sends the first domain name and the third information to the first UPF network element. Further, the SMF network element also determines the second information at least according to the location information of the UE and the first information, and sends the first domain name and the second information to the first UPF network element. When the first UPF network element receives the first request from the terminal device and the first request includes the first domain name, the first UPF network element determines the second request according to the second information and the third information, and sends it to the first DNS server The second request is for the first IP address corresponding to the first domain name obtained by the first DNS server. When the terminal device uses the first IP address to access the first domain name at the location indicated by the location information of the terminal device, the terminal device can access the local service nearby, can reduce the time delay of accessing the service, and can improve the communication efficiency.

以下结合具体实施例对图6所示的实施例进行详细说明。The embodiment shown in FIG. 6 will be described in detail below in conjunction with specific embodiments.

实施例1：如图8和图14所示，图8为UE请求域名对应的IP地址的具体流程图之一，图14为图8所示实施例可能涉及的网元组成的网络架构的示意图。SMF网元上配置应用平台对应的DNAI与应用平台对应的IP地址的对应关系，如表4所示。AF网元将APP ID、FQDN以及应用平台对应的DNAI的对应关系存储在UDR中，如表1所示。Embodiment 1: As shown in FIG. 8 and FIG. 14, FIG. 8 is one of the specific flowcharts of the UE requesting the IP address corresponding to the domain name, and FIG. 14 is a schematic diagram of the network architecture composed of network elements that may be involved in the embodiment shown in FIG. . The corresponding relationship between the DNAI corresponding to the application platform and the IP address corresponding to the application platform is configured on the SMF network element, as shown in Table 4. The AF network element stores the correspondence between APP ID, FQDN, and the DNAI corresponding to the application platform in the UDR, as shown in Table 1.

S801：UE发起PDU会话建立流程。S801: The UE initiates a PDU session establishment process.

具体的，UE携带PDU会话标识、S-NSSAI和DNN等参数发给AMF网元。AMF网元根据S-NSSAI和DNN选择SMF网元，并将AMF网元的标识、UE的永久标识、UE的位置信息、PDU会话标识，S-NSSAI和DNN等参数发送给SMF网元。其中，UE的位置信息包括UE的TAI。Specifically, the UE carries the PDU session identifier, S-NSSAI and DNN and other parameters and sends it to the AMF network element. The AMF network element selects the SMF network element according to the S-NSSAI and DNN, and sends parameters such as the AMF network element's identity, the UE's permanent identity, the location information of the UE, the PDU session identity, and the S-NSSAI and DNN to the SMF network element. Wherein, the location information of the UE includes the TAI of the UE.

S802：SMF向PCF发送服务化操作策略建立控制请求(Npcf_SMPolicy Control_Create Request)，该请求用于从PCF获取该PDU会话相关的策略信息。S802: The SMF sends a service-oriented operation policy establishment control request (Npcf_SMPolicy Control_Create Request) to the PCF. The request is used to obtain policy information related to the PDU session from the PCF.

S803：PCF向UDR发送服务化操作请求(Nudr_DM_Query)，该请求用于从UDR获取该UE签约的多个应用相关的信息和表1。S803: The PCF sends a servicing operation request (Nudr_DM_Query) to the UDR. The request is used to obtain information and Table 1 related to multiple applications subscribed by the UE from the UDR.

S804：UDR向PCF发送服务化操作响应(Nudr_DM_Response)，该响应包括该UE签约的多个应用相关的信息和表1，该UE签约的多个应用相关的信息包括UE签约的多个应用的标识。S804: The UDR sends a service operation response (Nudr_DM_Response) to the PCF. The response includes information related to multiple applications subscribed by the UE and Table 1, and the information related to multiple applications subscribed by the UE includes the identifiers of multiple applications subscribed by the UE. .

S805：PCF生成策略计费控制规则(Policy and Charging Control rule,PCC rule)，通过服务化操作策略建立控制响应(Npcf_SMPolicyControl_Create Response)发送至SMF，SMF保存PCC rule。PCC rule包括UE签约的多个应用的标识和表1。S805: The PCF generates a policy and charging control rule (Policy and Charging Control rule, PCC rule), and sends a control response (Npcf_SMPolicyControl_Create Response) to the SMF through the service-oriented operation policy establishment control response (Npcf_SMPolicyControl_Create Response), and the SMF saves the PCC rule. The PCC rule includes the identities of multiple applications subscribed by the UE and Table 1.

应理解的是，若SMF上本地配置表1，则上述S802～S805中不需要包括表1。It should be understood that if Table 1 is configured locally on the SMF, Table 1 does not need to be included in the foregoing S802 to S805.

S806：SMF网元确定多个域名分别对应的ECS option list。S806: The SMF network element determines the ECS option list corresponding to multiple domain names.

针对多个域名中的每个域名，SMF网元根据表1和UE当前的TAI，确定每个域名对应的DNAI list，如表2所示，以及根据每个域名对应的DNAI list和表4，得到表5，根据表5进一步确定多个域名分别对应的ECS option list，如表6所示。其中，多个域名是指与UE签约的多个应用中的每个应用对应的域名。For each of the multiple domain names, the SMF network element determines the DNAI list corresponding to each domain name according to Table 1 and the current TAI of the UE, as shown in Table 2, and according to the DNAI list corresponding to each domain name and Table 4. Obtain Table 5, and further determine the ECS option list corresponding to multiple domain names according to Table 5, as shown in Table 6. The multiple domain names refer to the domain names corresponding to each of the multiple applications contracted by the UE.

其中，DNAI list包括至少一个DNAI，ECS option list包括与至少一个DNAI分别对应的ECS option。每一个ECS option包括一个IP地址。其中，ECS option中包含的IP地址是应用平台对应IP地址，对该IP地址的描述可以参考前面的描述，重复之处不在赘述。S807：SMF网元向UPF发送N4会话建立请求消息，该N4会话建立请求消息包括translation table以及指示信息。translation table包括多个域名分别对应的ECS option list，指示信息指示UPF接收到UE发送的第一DNS请求消息包括多个域名中的任意一个域名时，将该域名对应的ECS option list添加到第一DNS请求，获得第二DNS请求，并将第二DNS请求发送至集中DNS服务器。Among them, the DNAI list includes at least one DNAI, and the ECS option list includes ECS options respectively corresponding to the at least one DNAI. Each ECS option includes an IP address. Among them, the IP address contained in the ECS option is the IP address corresponding to the application platform. For the description of the IP address, please refer to the previous description, and the repetition will not be repeated. S807: The SMF network element sends an N4 session establishment request message to the UPF. The N4 session establishment request message includes a translation table and indication information. The translation table includes the ECS option list corresponding to multiple domain names, and the indication information indicates that when the first DNS request message sent by the UE includes any one of the multiple domain names, the UPF adds the ECS option list corresponding to the domain name to the first DNS request, obtain the second DNS request, and send the second DNS request to the centralized DNS server.

具体的，SMF根据S-NSSAI和DNN等参数选择UPF作为本PDU会话的锚点。Specifically, SMF selects UPF as the anchor point of the PDU session according to parameters such as S-NSSAI and DNN.

S808：UE向UPF发送第一DNS查询请求。第一DNS查询请求携带FQDN。S808: The UE sends the first DNS query request to the UPF. The first DNS query request carries the FQDN.

S809：UPF确定存在第一DNS查询请求携带FQDN对应的ECS option list。S809: The UPF determines that the first DNS query request carries the ECS option list corresponding to the FQDN.

在UPF接收到第一DNS查询请求之后，UPF检查第一DNS查询请求中携带的FQDN是否包含在translation table中。如果包含，确定translation table中该FQDN对应的ECS option list。After the UPF receives the first DNS query request, the UPF checks whether the FQDN carried in the first DNS query request is included in the translation table. If it does, determine the ECS option list corresponding to the FQDN in the translation table.

S810：UPF向集中DNS服务器发送第二DNS查询请求。S810: The UPF sends a second DNS query request to the centralized DNS server.

UPF将该FQDN对应的ECS option list添加到第一DNS查询请求中，获得第二DNS请求。这里的集中DNS服务器可以是由运营商部署的集中式DNS服务器。UPF adds the ECS option list corresponding to the FQDN to the first DNS query request, and obtains the second DNS request. The centralized DNS server here may be a centralized DNS server deployed by an operator.

S811：集中DNS服务器向UPF发送DNS响应消息，DNS响应消息携带该FQDN对应的IP地址和该IP地址的TTL和目标ECS option。S811: The centralized DNS server sends a DNS response message to the UPF. The DNS response message carries the IP address corresponding to the FQDN, the TTL of the IP address and the target ECS option.

如果ECS option list中包括一个ECS option，集中DNS服务器确定该ECS option中的IP地址指向的应用平台，进一步地，确定该应用平台上部署的服务器的IP地址，作为该FQDN对应的IP地址，且该服务器支持该FQDN。该ECS option为目标ECS option。If an ECS option is included in the ECS option list, the centralized DNS server determines the application platform that the IP address in the ECS option points to, and further determines the IP address of the server deployed on the application platform as the IP address corresponding to the FQDN, and The server supports the FQDN. The ECS option is the target ECS option.

如果ECS option list中包括多个ECS option，集中DNS服务器可以从多个ECS option中选择目标ECS option，并进一步确定该目标ECS option指向的应用平台上部署的服务器的IP地址，作为该FQDN对应的IP地址，且该服务器支持该FQDN。If the ECS option list includes multiple ECS options, the centralized DNS server can select the target ECS option from multiple ECS options, and further determine the IP address of the server deployed on the application platform to which the target ECS option points, as the corresponding FQDN IP address, and the server supports the FQDN.

S812：UPF向SMF发送目标ECS option。S812: The UPF sends the target ECS option to the SMF.

S813：SMF网元为该PDU会话选择本地PSA网元以及选择ULCL或BP。S813: The SMF network element selects the local PSA network element and ULCL or BP for the PDU session.

具体地，SMF网元根据目标ECS option确定目标DNAI，根据目标DNAI为该PDU会话选择本地PSA网元，进一步地，SMF还根据目标DNAI为该PDU会话选择ULCL或BP，实现本地分流，优化业务访问的路径，提高通信效率。Specifically, the SMF network element determines the target DNAI according to the target ECS option, and selects the local PSA network element for the PDU session according to the target DNAI. Furthermore, the SMF also selects ULCL or BP for the PDU session according to the target DNAI to achieve local offloading and optimize services. The access path improves communication efficiency.

S814：UPF向UE发送DNS响应消息，DNS响应消息携带该FQDN对应的IP地址。S814: The UPF sends a DNS response message to the UE, and the DNS response message carries the IP address corresponding to the FQDN.

实施例2：如图9和图14所示，图9为UE请求域名对应的IP地址的具体流程图之二，图14为图9所示实施例可能涉及的网元组成的网络架构的示意图。AF网元将APP ID、FQDN以及应用平台对应的DNAI的对应关系存储在UDR中，如表1所示。Embodiment 2: As shown in FIG. 9 and FIG. 14, FIG. 9 is the second specific flowchart of the UE requesting the IP address corresponding to the domain name, and FIG. 14 is a schematic diagram of the network architecture composed of network elements that may be involved in the embodiment shown in FIG. 9 . The AF network element stores the correspondence between APP ID, FQDN, and the DNAI corresponding to the application platform in the UDR, as shown in Table 1.

S901～S905可以具体参考S801～S805，重复之处不再赘述。For S901 to S905, please refer to S801 to S805 for details, and the repetition will not be repeated.

S906：SMF网元确定多个域名分别对应的DNAI list。S906: The SMF network element determines the DNAI lists corresponding to multiple domain names.

针对多个域名中的每个域名，SMF网元根据表1和UE当前的TAI，确定每个域名对应的DNAI list，如表2所示，以及根据表2得到表3。其中，多个域名是指与UE签约的多个应用中的每个应用对应的域名。For each of the multiple domain names, the SMF network element determines the DNAI list corresponding to each domain name according to Table 1 and the current TAI of the UE, as shown in Table 2, and Table 3 is obtained according to Table 2. The multiple domain names refer to the domain names corresponding to each of the multiple applications contracted by the UE.

其中，DNAI list包括至少一个DNAI。Among them, the DNAI list includes at least one DNAI.

S907：SMF网元向UPF发送N4会话建立请求消息，该N4会话建立请求消息包括translation table以及指示信息。translation table包括多个域名分别对应的DNAI list，指示信息指示UPF接收到UE发送的第一DNS请求消息包括多个域名中的任意一个域名时，将该域名对应的DNAI list添加到第一DNS请求，获得第二DNS请求，并将第二DNS请求发送至集中DNS服务器。S907: The SMF network element sends an N4 session establishment request message to the UPF. The N4 session establishment request message includes a translation table and indication information. The translation table includes the DNAI list corresponding to multiple domain names, and the indication information indicates that when the first DNS request message sent by the UE includes any one of the multiple domain names, the UPF adds the DNAI list corresponding to the domain name to the first DNS request. , Obtain the second DNS request, and send the second DNS request to the centralized DNS server.

S908：UE向UPF发送第一DNS查询请求。第一DNS查询请求携带FQDN。S908: The UE sends the first DNS query request to the UPF. The first DNS query request carries the FQDN.

S909：UPF确定存在第一DNS查询请求携带FQDN对应的DNAI list。S909: The UPF determines that the first DNS query request carries the DNAI list corresponding to the FQDN.

在UPF接收到第一DNS查询请求之后，UPF检查第一DNS查询请求中携带的FQDN是否包含在translation table中。如果包含，确定translation table中该FQDN对应的DNAI list。After the UPF receives the first DNS query request, the UPF checks whether the FQDN carried in the first DNS query request is included in the translation table. If it does, determine the DNAI list corresponding to the FQDN in the translation table.

S910：UPF向集中DNS服务器发送第二DNS查询请求。S910: The UPF sends a second DNS query request to the centralized DNS server.

UPF将该FQDN对应的DNAI list添加到第一DNS查询请求中，获得第二DNS请求。这里的集中DNS服务器可以是由运营商部署的集中式DNS服务器。UPF adds the DNAI list corresponding to the FQDN to the first DNS query request, and obtains the second DNS request. The centralized DNS server here may be a centralized DNS server deployed by an operator.

S911：集中DNS服务器向UPF发送DNS响应消息，DNS响应消息携带该FQDN对应的IP地址和该IP地址的TTL和目标DNAI。S911: The centralized DNS server sends a DNS response message to the UPF. The DNS response message carries the IP address corresponding to the FQDN and the TTL and target DNAI of the IP address.

如果DNAI list中包括一个DNAI，集中DNS服务器确定该DNAI指向的应用平台，进一步地，确定该应用平台上部署的服务器的IP地址，作为该FQDN对应的IP地址，且该服务器支持该FQDN。该DNAI为目标DNAI。If the DNAI list includes a DNAI, the centralized DNS server determines the application platform that the DNAI points to, and further determines the IP address of the server deployed on the application platform as the IP address corresponding to the FQDN, and the server supports the FQDN. This DNAI is the target DNAI.

如果DNAI list中包括多个DNAI，集中DNS服务器可以从多个DNAI中选择目标DNAI，并进一步确定该目标DNAI指向的应用平台上部署的服务器的IP地址，作为该FQDN对应的IP地址，且该服务器支持该FQDN。If the DNAI list includes multiple DNAIs, the centralized DNS server can select the target DNAI from the multiple DNAIs, and further determine the IP address of the server deployed on the application platform to which the target DNAI points, as the IP address corresponding to the FQDN, and The server supports this FQDN.

S912：UPF向SMF发送目标DNAI。S912: UPF sends target DNAI to SMF.

S913：SMF网元为该PDU会话选择本地PSA网元以及选择ULCL或BP。S913: The SMF network element selects a local PSA network element and selects ULCL or BP for the PDU session.

具体地，SMF网元根据目标DNAI为该PDU会话选择本地PSA网元，进一步地，SMF还根据目标DNAI为该PDU会话选择ULCL或BP，实现本地分流，优化业务访问的路径，提高通信效率。Specifically, the SMF network element selects a local PSA network element for the PDU session according to the target DNAI. Further, the SMF also selects ULCL or BP for the PDU session according to the target DNAI to achieve local offloading, optimize the service access path, and improve communication efficiency.

S914：UPF向UE发送DNS响应消息，DNS响应消息携带该FQDN对应的IP地址。S914: The UPF sends a DNS response message to the UE, and the DNS response message carries the IP address corresponding to the FQDN.

实施例3：如图10和图14所示，图10为UE请求域名对应的IP地址的具体流程图之三，图14为图8所示实施例可能涉及的网元组成的网络架构的示意图。SMF网元上配置应用平台对应的DNAI与应用平台对应的本地DNS服务器的IP地址的对应关系，如表7所示。AF网元将APP ID、FQDN以及应用平台对应的DNAI的对应关系存储在UDR中，如表1所示。Embodiment 3: As shown in FIG. 10 and FIG. 14, FIG. 10 is the third specific flowchart of the UE requesting the IP address corresponding to the domain name, and FIG. 14 is a schematic diagram of the network architecture composed of network elements that may be involved in the embodiment shown in FIG. . The corresponding relationship between the DNAI corresponding to the application platform and the IP address of the local DNS server corresponding to the application platform is configured on the SMF network element, as shown in Table 7. The AF network element stores the correspondence between APP ID, FQDN, and the DNAI corresponding to the application platform in the UDR, as shown in Table 1.

S1001～S1005可以具体参考S801～S805，重复之处不再赘述。For S1001 to S1005, please refer to S801 to S805 for details, and the repetition will not be repeated here.

S1006：SMF网元确定多个域名分别对应的第一本地DNS服务器的IP地址。S1006: The SMF network element determines the IP addresses of the first local DNS servers respectively corresponding to the multiple domain names.

SMF网元根据表1和UE当前的TAI，确定每个域名对应的DNAI list，如表2所示，以及根据每个域名对应的DNAI list和表7，得到表8，根据表8进一步确定多个域名分别对应的第一本地DNS服务器的IP地址，如表9所示。其中，多个域名是指与UE签约的多个应用中的每个应用对应的域名。The SMF network element determines the DNAI list corresponding to each domain name according to Table 1 and the current TAI of the UE, as shown in Table 2, and according to the DNAI list corresponding to each domain name and Table 7, to obtain Table 8, and further determine the number according to Table 8. Each domain name corresponds to the IP address of the first local DNS server, as shown in Table 9. The multiple domain names refer to the domain names corresponding to each of the multiple applications contracted by the UE.

S1007：SMF网元向UPF发送N4会话建立请求消息，该N4会话建立请求消息包括translation table以及指示信息。translation table包括多个域名分别对应的本地DNS服务器的IP地址，指示信息指示UPF接收到UE发送的第一DNS请求消息包括多个域名中的任意一个域名时，将第一DNS请求的目标地址修改为该域名对应的第一本地DNS服务器的IP地址，获得第二DNS请求，并将第二DNS请求发送至该域名对应的第一本地DNS服务器。S1007: The SMF network element sends an N4 session establishment request message to the UPF. The N4 session establishment request message includes a translation table and indication information. The translation table includes the IP addresses of the local DNS servers corresponding to multiple domain names. The indication information indicates that when the first DNS request message sent by the UE includes any one of the multiple domain names, the UPF will modify the target address of the first DNS request. Obtain a second DNS request for the IP address of the first local DNS server corresponding to the domain name, and send the second DNS request to the first local DNS server corresponding to the domain name.

S1008：UE向UPF发送第一DNS查询请求。第一DNS查询请求携带FQDN。S1008: The UE sends the first DNS query request to the UPF. The first DNS query request carries the FQDN.

S1009：UPF确定存在第一DNS查询请求携带的FQDN对应的第一本地DNS服务器。S1009: The UPF determines that there is a first local DNS server corresponding to the FQDN carried in the first DNS query request.

在UPF接收到第一DNS查询请求之后，UPF检查第一DNS查询请求中携带的FQDN是否包含在translation table中。如果包含，确定translation table中该FQDN对应的第一本地DNS服务器。After the UPF receives the first DNS query request, the UPF checks whether the FQDN carried in the first DNS query request is included in the translation table. If it does, determine the first local DNS server corresponding to the FQDN in the translation table.

S1010：UPF向该FQDN对应的第一本地DNS服务器发送第二DNS查询请求。S1010: The UPF sends a second DNS query request to the first local DNS server corresponding to the FQDN.

UPF将第一DNS请求的目标地址修改为该FQDN对应的第一本地DNS服务器的IP地址，获得第二DNS请求。UPF modifies the target address of the first DNS request to the IP address of the first local DNS server corresponding to the FQDN, and obtains the second DNS request.

S1011：该FQDN对应的第一本地DNS服务器向UPF发送DNS响应消息，DNS响应消息携带该FQDN对应的IP地址和该IP地址的TTL。S1011: The first local DNS server corresponding to the FQDN sends a DNS response message to the UPF. The DNS response message carries the IP address corresponding to the FQDN and the TTL of the IP address.

S1012：UPF向SMF发送目标DNAI。S1012: UPF sends target DNAI to SMF.

UPF根据DNS响应消息中携带的该FQDN对应的IP地址确定该IP地址指向的服务器所在的应用平台的DNAI(称为目标DNAI)。The UPF determines the DNAI (referred to as the target DNAI) of the application platform where the server pointed to by the IP address is located according to the IP address corresponding to the FQDN carried in the DNS response message.

例如，UPF上本地配置或者从其他网元获取IP地址空间(或者IP地址段)与该IP地址空间对应的应用平台的DNAI之间的对应关系。示例性地，UPF可以通过AF获取上述配置内容。当UPF获取该FQDN对应的IP地址时，可以确定该IP地址所在的地址空间(或者IP地址段)，进一步地，确定与该地址空间(或者IP地址段)对应的应用平台的DNAI。For example, the corresponding relationship between the IP address space (or IP address segment) and the DNAI of the application platform corresponding to the IP address space is locally configured on the UPF or obtained from other network elements. Exemplarily, the UPF can obtain the above configuration content through AF. When the UPF obtains the IP address corresponding to the FQDN, it can determine the address space (or IP address segment) where the IP address is located, and further, determine the DNAI of the application platform corresponding to the address space (or IP address segment).

S1013：SMF网元为该PDU会话选择本地PSA网元以及选择ULCL或BP。S1013: The SMF network element selects a local PSA network element and selects ULCL or BP for the PDU session.

S1014：UPF向UE发送DNS响应消息，DNS响应消息携带该FQDN对应的IP地址。S1014: The UPF sends a DNS response message to the UE, and the DNS response message carries the IP address corresponding to the FQDN.

以下结合具体实施例对图7所示的实施例进行详细说明。The embodiment shown in FIG. 7 will be described in detail below in conjunction with specific embodiments.

实施例4：如图11和图14所示，图11为UE请求域名对应的IP地址的具体流程图之四，图14为图11所示实施例可能涉及的网元组成的网络架构的示意图。SMF网元上配置应用平台对应的DNAI与应用平台对应的IP地址的对应关系，如表13所示，以及APP ID、FQDN以及应用平台对应的DNAI的对应关系如表1所示。Embodiment 4: As shown in FIG. 11 and FIG. 14, FIG. 11 is the fourth specific flowchart of the UE requesting the IP address corresponding to the domain name, and FIG. 14 is a schematic diagram of the network architecture composed of network elements that may be involved in the embodiment shown in FIG. 11 . The corresponding relationship between the DNAI corresponding to the application platform and the IP address corresponding to the application platform is configured on the SMF network element, as shown in Table 13, and the corresponding relationship between the APP ID, FQDN, and the DNAI corresponding to the application platform is shown in Table 1.

S1101：SMF网元确定第一对应关系。S1101: The SMF network element determines the first correspondence.

其中，第一对应关系为域名、与域名对应的应用所在至少一个应用平台的index，与域名对应的应用平台对应的IP地址的对应关系。SMF网元根据表1、表13以及应用平台对应的DNAI与应用平台的index的对应关系确定第一对应关系，如表16所示。The first correspondence is a domain name, an index of at least one application platform where an application corresponding to the domain name is located, and an IP address corresponding to the application platform corresponding to the domain name. The SMF network element determines the first corresponding relationship according to Table 1, Table 13 and the corresponding relationship between the DNAI corresponding to the application platform and the index of the application platform, as shown in Table 16.

S1102：SMF网元向UPF发送translation table。S1102: The SMF network element sends a translation table to the UPF.

其中，translation table包括第一对应关系。Among them, the translation table includes the first corresponding relationship.

S1103：UE发起PDU会话建立流程。S1103: The UE initiates a PDU session establishment process.

具体的，UE携带PDU会话标识、S-NSSAI和DNN等参数发给AMF网元。AMF网元根据S-NSSAI和DNN选择SMF网元，并将AMF网元的标识、UE的永久标识、UE的位置信息、PDU会话标识，S-NSSAI和DNN等参数发送给SMF网元。其中，UE的位置信息包括UE的TAI。SMF为该PDU会话选择锚点UPF网元。Specifically, the UE carries the PDU session identifier, S-NSSAI and DNN and other parameters and sends it to the AMF network element. The AMF network element selects the SMF network element according to the S-NSSAI and DNN, and sends parameters such as the AMF network element's identity, the UE's permanent identity, the location information of the UE, the PDU session identity, and the S-NSSAI and DNN to the SMF network element. Wherein, the location information of the UE includes the TAI of the UE. SMF selects the anchor UPF network element for the PDU session.

S1104：SMF向PCF发送服务化操作策略建立控制请求(Npcf_SMPolicy Control_Create Request)，该请求用于从PCF获取该PDU会话相关的策略信息。S1104: The SMF sends a service-oriented operation policy establishment control request (Npcf_SMPolicy Control_Create Request) to the PCF. The request is used to obtain policy information related to the PDU session from the PCF.

S1105：PCF向UDR发送服务化操作请求(Nudr_DM_Query)，该请求用于从UDR获取该UE签约的应用相关的信息。S1105: The PCF sends a service operation request (Nudr_DM_Query) to the UDR. The request is used to obtain information related to the application subscribed by the UE from the UDR.

S1106：UDR向PCF发送服务化操作响应(Nudr_DM_Response)，该响应包括该UE签约的多个应用相关的信息。该UE签约的多个应用相关的信息包括UE签约的多个应用的标识。S1106: The UDR sends a service operation response (Nudr_DM_Response) to the PCF, where the response includes information related to multiple applications subscribed by the UE. The information related to the multiple applications subscribed by the UE includes the identities of the multiple applications subscribed by the UE.

S1107：PCF生成策略计费控制规则(Policy and Charging Control rule,PCC rule)，通过服务化操作策略建立控制响应(Npcf_SMPolicyControl_Create Response)发送至SMF，SMF保存PCC rule。PCC rule包括UE签约的多个应用的标识。S1107: The PCF generates a policy and charging control rule (Policy and Charging Control rule, PCC rule), and sends a control response (Npcf_SMPolicyControl_Create Response) to the SMF through a service-based operation policy establishment, and the SMF saves the PCC rule. The PCC rule includes the identities of multiple applications subscribed by the UE.

S1108：SMF网元确定多个域名分别对应的ECS option list中的每个ECS option的索引信息。S1108: The SMF network element determines the index information of each ECS option in the ECS option list corresponding to multiple domain names.

其中，多个域名是指与UE签约的多个应用中的每个应用对应的域名。The multiple domain names refer to the domain names corresponding to each of the multiple applications contracted by the UE.

针对多个域名中的每个域名，SMF网元根据表1和UE当前的TAI，确定每个域名对应的DNAI list，如表11所示，以及根据每个域名对应的DNAI list和表13，得到表17，根据表17进一步确定多个域名分别对应的ECS option list中的每个ECS option，如表18所示。For each of the multiple domain names, the SMF network element determines the DNAI list corresponding to each domain name according to Table 1 and the current TAI of the UE, as shown in Table 11, and according to the DNAI list and Table 13 corresponding to each domain name, Obtain Table 17, and further determine each ECS option in the ECS option list corresponding to multiple domain names according to Table 17, as shown in Table 18.

其中，DNAI list包括至少一个DNAI。ECS option list包括与至少一个DNAI分别对应的ECS option。每一个ECS option包括一个IP地址。其中，ECS option中包含的IP地址是应用平台对应IP地址，对该IP地址的描述可以参考前面的描述，重复之处不在赘述。S1109：SMF网元向UPF发送N4会话建立请求消息，该N4会话建立请求消息包括translation table以及指示信息。translation table包括多个域名分别对应的ECS option list中的每个ECS option的索引信息，指示信息指示UPF接收到UE发送的第一DNS请求消息包括多个域名中的任意一个域名时，根据第一对应关系和该域名对应的ECS option list中的每个ECS option的索引信息确定该域名对应的ECS option list，将该域名对应的ECS option list添加到第一DNS请求，获得第二DNS请求，并将第二DNS请求发送至集中DNS服务器。Among them, the DNAI list includes at least one DNAI. The ECS option list includes ECS options corresponding to at least one DNAI respectively. Each ECS option includes an IP address. Among them, the IP address contained in the ECS option is the IP address corresponding to the application platform. For the description of the IP address, please refer to the previous description, and the repetition will not be repeated. S1109: The SMF network element sends an N4 session establishment request message to the UPF. The N4 session establishment request message includes a translation table and indication information. The translation table includes index information of each ECS option in the ECS option list corresponding to multiple domain names. The indication information indicates that when the first DNS request message sent by the UE includes any one of the multiple domain names, the UPF receives the first DNS request message. The corresponding relationship and the index information of each ECS option in the ECS option list corresponding to the domain name determines the ECS option list corresponding to the domain name, adds the ECS option list corresponding to the domain name to the first DNS request, and obtains the second DNS request, and Send the second DNS request to the centralized DNS server.

S1110：UE向UPF发送第一DNS查询请求。第一DNS查询请求携带FQDN。S1110: The UE sends the first DNS query request to the UPF. The first DNS query request carries the FQDN.

S1111：UPF确定第一DNS查询请求携带FQDN对应的ECS option list。S1111: The UPF determines that the first DNS query request carries the ECS option list corresponding to the FQDN.

在UPF接收到第一DNS查询请求之后，UPF检查第一DNS查询请求中携带的FQDN是否包含在translation table中。如果包含，确定translation table中该FQDN对应的ECS option list中的每个ECS option的索引信息，根据第一对应关系和该FQDN对应的ECS option中的每个ECS option的索引信息确定该FQDN对应的ECS option list。After the UPF receives the first DNS query request, the UPF checks whether the FQDN carried in the first DNS query request is included in the translation table. If included, determine the index information of each ECS option in the ECS option list corresponding to the FQDN in the translation table, and determine the index information of each ECS option in the ECS option corresponding to the FQDN according to the first correspondence ECS option list.

S1112～S1116可以具体参考S810～S814，重复之处不再赘述。For S1112 to S1116, please refer to S810 to S814 for details, and the repetition is not repeated here.

实施例5：如图12和图14所示，图12为UE请求域名对应的IP地址的具体流程图之五，图12为图9所示实施例可能涉及的网元组成的网络架构的示意图。SMF网元上配置APP ID、FQDN以及应用平台对应的DNAI的对应关系如表1所示。Embodiment 5: As shown in FIG. 12 and FIG. 14, FIG. 12 is the fifth specific flowchart of the UE requesting the IP address corresponding to the domain name, and FIG. 12 is a schematic diagram of the network architecture composed of network elements that may be involved in the embodiment shown in FIG. 9 . Table 1 shows the correspondence between the APP ID, FQDN and the DNAI corresponding to the application platform configured on the SMF network element.

S1201：SMF网元确定第二对应关系。S1201: The SMF network element determines the second correspondence.

其中，第一对应关系为域名、与域名对应的应用所在至少一个应用平台的index，与域名对应的应用平台对应的DNAI的对应关系。SMF网元根据表1和应用平台对应的DNAI与应用平台的index的对应关系确定第二对应关系，如表10所示。The first correspondence is the domain name, the index of at least one application platform where the application corresponding to the domain name is located, and the correspondence relationship between DNAI corresponding to the application platform corresponding to the domain name. The SMF network element determines the second correspondence relationship according to Table 1 and the correspondence relationship between the DNAI corresponding to the application platform and the index of the application platform, as shown in Table 10.

S1202：SMF网元向UPF发送translation table。S1202: The SMF network element sends a translation table to the UPF.

其中，translation table包括第二对应关系。Among them, the translation table includes the second correspondence.

S1203～S1206可以具体参考S1103～S1106，重复之处不再赘述。For S1203 to S1206, please refer to S1103 to S1106 for details, and the repetition will not be repeated.

S1207：SMF网元确定多个域名分别对应的DNAI list中的每个DNAI的索引信息。S1207: The SMF network element determines the index information of each DNAI in the DNAI list corresponding to multiple domain names.

针对多个域名中的每个域名，SMF网元根据表1和UE当前的TAI，确定每个域名对应的DNAI list，如表11所示，以及根据每个域名对应的DNAI list和表13，得到表17，根据表17进一步确定多个域名分别对应的DNAI list中的每个DNAI索引信息，如表18所示。For each of the multiple domain names, the SMF network element determines the DNAI list corresponding to each domain name according to Table 1 and the current TAI of the UE, as shown in Table 11, and according to the DNAI list and Table 13 corresponding to each domain name, Table 17 is obtained, and each DNAI index information in the DNAI list corresponding to multiple domain names is further determined according to Table 17, as shown in Table 18.

S1208：SMF网元向UPF发送N4会话建立请求消息，该N4会话建立请求消息包括translation table以及指示信息。translation table包括多个域名分别对应的ECS option list的索引信息，指示信息指示UPF接收到UE发送的第一DNS请求消息包括多个域名中的任意一个域名时，根据第二对应关系和该域名对应的DNAI list中的每个DNAI的索引信息确定该域名对应的DNAI list，将该域名对应的DNAI list添加到第一DNS请求，获得第二DNS请求，并将第二DNS请求发送至集中DNS服务器。S1208: The SMF network element sends an N4 session establishment request message to the UPF. The N4 session establishment request message includes a translation table and indication information. The translation table includes the index information of the ECS option list corresponding to multiple domain names. The indication information indicates that when the first DNS request message sent by the UE includes any one of the multiple domain names, the UPF corresponds to the domain name according to the second correspondence. The index information of each DNAI in the DNAI list determines the DNAI list corresponding to the domain name, adds the DNAI list corresponding to the domain name to the first DNS request, obtains the second DNS request, and sends the second DNS request to the centralized DNS server .

S1209：UE向UPF发送第一DNS查询请求。第一DNS查询请求携带FQDN。S1209: The UE sends the first DNS query request to the UPF. The first DNS query request carries the FQDN.

S1210：UPF确定存在第一DNS查询请求携带FQDN对应的DNAI list。S1210: The UPF determines that the first DNS query request carries the DNAI list corresponding to the FQDN.

在UPF接收到第一DNS查询请求之后，UPF检查第一DNS查询请求中携带的FQDN是否包含在translation table中。如果包含，确定translation table中该FQDN对应的DNAI list中的每个DNAI的索引信息，根据第二对应关系和该FQDN对应的DNAI list中的每个DNAI的索引信息确定该FQDN对应的DNAI list。After the UPF receives the first DNS query request, the UPF checks whether the FQDN carried in the first DNS query request is included in the translation table. If it does, determine the index information of each DNAI in the DNAI list corresponding to the FQDN in the translation table, and determine the DNAI list corresponding to the FQDN according to the second correspondence and the index information of each DNAI in the DNAI list corresponding to the FQDN.

S1211～S1215可以具体参考S909～S913，重复之处不再赘述。For S1211 to S1215, please refer to S909 to S913 for details, and the repetition is not repeated here.

实施例6：如图13和图14所示，图13为UE请求域名对应的IP地址的具体流程图之六，图14为图9所示实施例可能涉及的网元组成的网络架构的示意图。SMF网元上配置应用平台对应的DNAI与应用平台对应的本地DNS服务器的IP地址的对应关系，如表19所示，以及APP ID、FQDN以及应用平台对应的DNAI的对应关系如表1所示。Embodiment 6: As shown in FIG. 13 and FIG. 14, FIG. 13 is the sixth specific flowchart of the UE requesting the IP address corresponding to the domain name, and FIG. 14 is a schematic diagram of the network architecture composed of network elements that may be involved in the embodiment shown in FIG. 9 . The corresponding relationship between the DNAI corresponding to the application platform and the IP address of the local DNS server corresponding to the application platform is configured on the SMF network element, as shown in Table 19, and the corresponding relationship between the APP ID, FQDN, and the DNAI corresponding to the application platform is shown in Table 1. .

S1301：SMF网元确定第三对应关系。S1301: The SMF network element determines the third correspondence.

其中，第一对应关系为域名、与域名对应的应用所在至少一个应用平台的index，与域名对应的应用平台对应的本地DNS服务器的IP地址的对应关系。SMF网元根据表1、表19和应用平台对应的DNAI与应用平台的index的对应关系确定第二对应关系，如表22所示。The first correspondence is the correspondence between the domain name, the index of at least one application platform where the application corresponding to the domain name is located, and the IP address of the local DNS server corresponding to the application platform corresponding to the domain name. The SMF network element determines the second correspondence relationship according to Table 1 and Table 19 and the correspondence relationship between the DNAI corresponding to the application platform and the index of the application platform, as shown in Table 22.

S1302：SMF网元向UPF发送translation table。S1302: The SMF network element sends a translation table to the UPF.

S1303～S1306可以具体参考S1103～S1106，重复之处不再赘述。For S1303 to S1306, please refer to S1103 to S1106 for details, and the repetition will not be repeated here.

S1307：SMF网元确定多个域名分别对应的第一本地DNS服务器的IP地址的索引信息。S1307: The SMF network element determines the index information of the IP address of the first local DNS server respectively corresponding to the multiple domain names.

针对多个域名中的每个域名，SMF网元根据表1和UE当前的TAI，确定每个域名对应的DNAI list，如表11所示，以及根据每个域名对应的DNAI list和表19，得到表23，根据表23进一步确定多个域名分别对应的DNAI list中的每个DNAI索引信息，如表24所示。For each of the multiple domain names, the SMF network element determines the DNAI list corresponding to each domain name according to Table 1 and the current TAI of the UE, as shown in Table 11, and according to the DNAI list and Table 19 corresponding to each domain name, Obtain Table 23, and further determine each DNAI index information in the DNAI list corresponding to multiple domain names according to Table 23, as shown in Table 24.

S1308：SMF网元向UPF发送N4会话建立请求消息，该N4会话建立请求消息包括translation table以及指示信息。translation table包括多个域名分别对应的ECS option list的索引信息，指示信息指示UPF接收到UE发送的第一DNS请求消息包括多个域名中的任意一个域名时，根据第三对应关系和该域名对应的第一本地DNS服务器的IP地址的索引信息确定该域名对应的第一本地DNS服务器的IP地址，将第一DNS请求的目标地址修改为该域名对应的第一本地DNS服务器的IP地址，获得第二DNS请求，并将第二DNS请求发送至该域名对应的第一本地DNS服务器。S1308: The SMF network element sends an N4 session establishment request message to the UPF. The N4 session establishment request message includes a translation table and indication information. The translation table includes index information of the ECS option list corresponding to multiple domain names. The indication information indicates that when the first DNS request message sent by the UE includes any one of the multiple domain names, the UPF corresponds to the domain name according to the third correspondence. The index information of the IP address of the first local DNS server determines the IP address of the first local DNS server corresponding to the domain name, and the target address of the first DNS request is modified to the IP address of the first local DNS server corresponding to the domain name to obtain And send the second DNS request to the first local DNS server corresponding to the domain name.

S1309：UE向UPF发送第一DNS查询请求。第一DNS查询请求携带FQDN。S1309: The UE sends the first DNS query request to the UPF. The first DNS query request carries the FQDN.

S1310：UPF确定存在第一DNS查询请求携带FQDN对应的第一本地DNS服务器的IP地址。S1310: The UPF determines that the first DNS query request carries the IP address of the first local DNS server corresponding to the FQDN.

在UPF接收到第一DNS查询请求之后，UPF检查第一DNS查询请求中携带的FQDN是否包含在translation table中。如果包含，确定translation table中该FQDN对应的第一本地DNS服务器的IP地址的索引信息，根据第三对应关系和该FQDN对应的第一本地DNS服务器的IP地址的索引信息确定该FQDN对应的第一本地DNS服务器的IP地址。After the UPF receives the first DNS query request, the UPF checks whether the FQDN carried in the first DNS query request is included in the translation table. If included, determine the index information of the IP address of the first local DNS server corresponding to the FQDN in the translation table, and determine the index information of the first local DNS server corresponding to the FQDN according to the third correspondence and the index information of the IP address of the first local DNS server corresponding to the FQDN The IP address of a local DNS server.

S1311～S1315可以具体参考S1009～S1013，重复之处不再赘述。For S1311 to S1315, please refer to S1009 to S1013 for details, and the repetition will not be repeated.

实施例7：Example 7:

如图15所示，当UE发生移动时，SMF获取UE当前所在的最新位置，例如新的(new)TAI。基于上述实施例1～6，UPF保存该UE的DNS查询记录，如表25所示：As shown in FIG. 15, when the UE moves, the SMF obtains the latest location where the UE is currently located, such as a new (new) TAI. Based on the foregoing embodiments 1 to 6, UPF saves the UE's DNS query records, as shown in Table 25:

表25Table 25

S1501：SMF根据new TAI确定新的翻译表(new translation table)。S1501: SMF determines a new translation table (new translation table) according to new TAI.

S1502：SMF向UPF发送new translation table。S1502: SMF sends new translation table to UPF.

S1503：UPF根据接收到的new translation table更新已保存的translation table，并UPF根据表25判断FQDN-1对应的new DNAI与UPF保存的DNS查询记录中的Target DNAI-1不同，且FQDN-1对应的TTL-1未超时。S1503: UPF updates the saved translation table according to the received new translation table, and UPF judges according to Table 25 that the new DNAI corresponding to FQDN-1 is different from the Target DNAI-1 in the DNS query record saved by UPF, and corresponds to FQDN-1 The TTL-1 has not timed out.

S1504：UPF向SMF发送通知消息。S1504: UPF sends a notification message to SMF.

示例性地，通知消息携带域名刷新指示(DNS flush indication)、PDU会话标识以及FQDN-1。Exemplarily, the notification message carries a DNS flush indication, a PDU session identifier, and FQDN-1.

示例性地，UPF可以通过N4接口向SMF发送通知消息。Exemplarily, the UPF can send a notification message to the SMF through the N4 interface.

S1505：SMF向UE发送NAS消息，NAS消息携带指示信息,以及FQDN-1。S1505: The SMF sends a NAS message to the UE. The NAS message carries indication information and FQDN-1.

具体地，SMF收到UPF发送的通知消息之后，根据域名刷新指示获知UE需要刷新FQDN-1对应的IP地址，则SMF向UE发送NAS消息，NAS消息携带指示信息。指示信息用于触发UE发起DNS查询。Specifically, after receiving the notification message sent by the UPF, the SMF learns that the UE needs to refresh the IP address corresponding to FQDN-1 according to the domain name refresh instruction, and the SMF sends a NAS message to the UE, and the NAS message carries the instruction information. The indication information is used to trigger the UE to initiate a DNS query.

S1506：UE向UPF发送DNS查询请求，DNS查询请求携带FQDN-1。S1506: The UE sends a DNS query request to the UPF, and the DNS query request carries FQDN-1.

具体的，UE在接收到NAS消息之后，获知FQDN-1对应的DNS缓存记录失效，则UE向UPF发送DNS查询请求，以请求FQDN-1对应的IP地址。Specifically, after the UE learns that the DNS cache record corresponding to FQDN-1 is invalid after receiving the NAS message, the UE sends a DNS query request to UPF to request the IP address corresponding to FQDN-1.

可以理解的，本申请实施例中，会话功能管理网元和/或第一用户面网元可以执行本申请实施例中的部分或全部步骤，这些步骤或操作仅是示例，本申请实施例还可以执行其它操作或者各种操作的变形。此外，各个步骤可以按照本申请实施例呈现的不同的顺序来执行，并且有可能并非要执行本申请实施例中的全部操作。It is understandable that in the embodiments of the present application, the session function management network element and/or the first user plane network element may perform some or all of the steps in the embodiments of the present application. These steps or operations are only examples, and the embodiments of the present application also Other operations or variations of various operations can be performed. In addition, each step may be executed in a different order presented in the embodiments of the present application, and it may not be necessary to perform all the operations in the embodiments of the present application.

在本申请的各个实施例中，如果没有特殊说明以及逻辑冲突，不同的实施例之间的术语和/或描述具有一致性、且可以相互引用，不同的实施例中的技术特征根据其内在的逻辑关系可以组合形成新的实施例。In the various embodiments of this application, if there are no special instructions and logical conflicts, the terms and/or descriptions between different embodiments are consistent and can be mutually cited. The technical features in different embodiments are based on their inherent Logical relationships can be combined to form new embodiments.

上述本申请提供的实施例中，分别从各个网元本身、以及从各个网元之间交互的角度对本申请实施例提供的通信方法的各方案进行了介绍。可以理解的是，各个网元，例如会话功能管理网元和第一用户面网元，为了实现上述功能，其包含了执行各个功能相应的硬件结构和/或软件模块。本领域技术人员应该很容易意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，本申请能够以硬件或硬件和计算机软件的结合形式来实现。某个功能究竟以硬件还是计算机软件驱动硬件的方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。In the above-mentioned embodiments provided by the present application, the solutions of the communication methods provided by the embodiments of the present application are respectively introduced from the perspective of each network element itself and the interaction between each network element. It can be understood that each network element, such as the session function management network element and the first user plane network element, includes hardware structures and/or software modules corresponding to each function in order to realize the above-mentioned functions. Those skilled in the art should easily realize that in combination with the units and algorithm steps of the examples described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed by hardware or computer software-driven hardware depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

与上述构思相同，如图16所示，本申请实施例还提供一种装置1600，该装置1600包括收发单元1602和处理单元1601。Similar to the above-mentioned concept, as shown in FIG. 16, an embodiment of the present application further provides an apparatus 1600. The apparatus 1600 includes a transceiver unit 1602 and a processing unit 1601.

一示例中，装置1600用于实现上述方法中会话功能管理网元的功能。该装置可以是会话功能管理网元。In an example, the apparatus 1600 is used to implement the function of the session function management network element in the foregoing method. The device may be a session function management network element.

其中，收发单元1602，用于接收来自于第一网元的第一信息，所述第一信息包括第一域名，和与所述第一域名对应的第一应用的标识中的至少一种；其中，所述第一域名为终端设备所请求的域名；Wherein, the transceiving unit 1602 is configured to receive first information from a first network element, where the first information includes at least one of a first domain name and an identification of a first application corresponding to the first domain name; Wherein, the first domain name is the domain name requested by the terminal device;

处理单元1601，用于至少根据所述第一信息和所述终端设备的位置信息确定第二信息；The processing unit 1601 is configured to determine second information at least according to the first information and the location information of the terminal device;

收发单元1602，用于向所述第一网元发送所述第二信息，所述第二信息用于获取所述第一域名对应的第一IP地址。The transceiver unit 1602 is configured to send the second information to the first network element, where the second information is used to obtain the first IP address corresponding to the first domain name.

一示例中，装置1600用于实现上述方法中第一用户面网元的功能。该装置可以是第一用户面网元。In an example, the apparatus 1600 is used to implement the function of the first user plane network element in the foregoing method. The device may be the first user plane network element.

其中，处理单元1601，用于获取第一信息，所述第一信息包括第一域名，和与所述第一域名对应的第一应用的标识中的至少一种；所述第一域名为终端设备所请求的域名；The processing unit 1601 is configured to obtain first information, where the first information includes at least one of a first domain name and an identification of a first application corresponding to the first domain name; the first domain name is a terminal The domain name requested by the device;

收发单元1602，用于向会话管理功能网元发送第一信息；The transceiver unit 1602 is configured to send the first information to the session management function network element;

收发单元1602，用于接收来自于所述会话管理功能网元的第二信息，所述第二信息用于获取所述第一域名对应的第一IP地址；The transceiving unit 1602 is configured to receive second information from the session management function network element, where the second information is used to obtain the first IP address corresponding to the first domain name;

收发单元1602，用于将所述第一IP地址发送至所述终端设备。The transceiver unit 1602 is configured to send the first IP address to the terminal device.

关于处理单元1601、收发单元1602的具体执行过程，可参见上方法实施例中的记载。本申请实施例中对模块的划分是示意性的，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，另外，在本申请各个实施例中的各功能模块可以集成在一个处理器中，也可以是单独物理存在，也可以两个或两个以上模块集成在一个模块中。上述集成的模块既可以采用硬件的形式实现，也可以采用软件功能模块的形式实现。For the specific execution process of the processing unit 1601 and the transceiving unit 1602, please refer to the record in the above method embodiment. The division of modules in the embodiments of this application is illustrative, and it is only a logical function division. In actual implementation, there may be other division methods. In addition, the functional modules in the various embodiments of this application can be integrated into one process. In the device, it can also exist alone physically, or two or more modules can be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or software functional modules.

作为另一种可选的变形，该装置可以为芯片***。本申请实施例中，芯片***可以由芯片构成，也可以包含芯片和其他分立器件。示例性地，该装置包括处理器和接口，该接口可以为输入/输出接口。其中，处理器完成上述处理单元1601的功能，接口完成上述收发单元1602的功能。该装置还可以包括存储器，存储器用于存储可在处理器上运行的程序，处理器执行该程序时实现上述各个实施例的方法。As another optional variation, the device may be a chip system. In the embodiments of the present application, the chip system may be composed of chips, or may include chips and other discrete devices. Exemplarily, the device includes a processor and an interface, and the interface may be an input/output interface. Among them, the processor completes the function of the aforementioned processing unit 1601, and the interface completes the function of the aforementioned transceiver unit 1602. The device may also include a memory, where the memory is used to store a program that can be run on the processor, and the processor implements the method of each of the foregoing embodiments when the program is executed by the processor.

与上述构思相同，如图17所示，本申请实施例还提供一种装置1700。该装置1700中包括：通信接口1701、至少一个处理器1702、至少一个存储器1703。通信接口1701，用于通过传输介质和其它设备进行通信，从而用于装置1700中的装置可以和其它设备进行通信。存储器1703，用于存储计算机程序。处理器1702调用存储器1703存储的计算机程序，通过通信接口1701收发数据实现上述实施例中的方法。Similar to the above-mentioned concept, as shown in FIG. 17, an embodiment of the present application further provides an apparatus 1700. The device 1700 includes: a communication interface 1701, at least one processor 1702, and at least one memory 1703. The communication interface 1701 is used to communicate with other devices through a transmission medium, so that the device used in the apparatus 1700 can communicate with other devices. The memory 1703 is used to store computer programs. The processor 1702 calls the computer program stored in the memory 1703, and transmits and receives data through the communication interface 1701 to implement the method in the foregoing embodiment.

示例性地，当该装置为会话功能管理网元时，存储器1703用于存储计算机程序；处理器1702调用存储器1703存储的计算机程序，通过通信接口1701执行上述实施例中终端设备执行的方法。当该装置为第一用户面网元时，存储器1703用于存储计算机程序；处理器1702调用存储器1703存储的计算机程序，通过通信接口1701执行上述实施例中网络设备执行的方法。Exemplarily, when the device is a session function management network element, the memory 1703 is used to store a computer program; the processor 1702 calls the computer program stored in the memory 1703, and executes the method executed by the terminal device in the foregoing embodiment through the communication interface 1701. When the device is the first user plane network element, the memory 1703 is used to store a computer program; the processor 1702 calls the computer program stored in the memory 1703, and executes the method executed by the network device in the foregoing embodiment through the communication interface 1701.

在本申请实施例中，通信接口1701可以是收发器、电路、总线、模块或其它类型的通信接口。处理器1702可以是通用处理器、数字信号处理器、专用集成电路、现场可编程门阵列或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件，可以实现或者执行本申请实施例中的公开的各方法、步骤及逻辑框图。通用处理器可以是微处理器或者任何常规的处理器等。结合本申请实施例所公开的方法的步骤可以直接体现为硬件处理器执行完成，或者用处理器中的硬件及软件模块组合执行完成。存储器1703可以是非易失性存储器，比如硬盘(hard disk drive，HDD)或固态硬盘(solid-state drive，SSD)等，还可以是易失性存储器(volatile memory)，例如随机存取存储器(random-access memory，RAM)。存储器是能够用于携带或存储具有指令或数据结构形式的期望的程序代码并能够由计算机存取的任何其他介质，但不限于此。本申请实施例中的存储器还可以是电路或者其它任意能够实现存储功能的装置。存储器1703和处理器1702耦合。本申请实施例中的耦合是装置、单元或模块之间的间隔耦合或通信连接，可以是电性，机械或其它的形式，用于装置、单元或模块之间的信息交互。作为另一种实现，存储器1703还可以位于装置1700之外。处理器1702可以和存储器1703协同操作。处理器1702可以执行存储器1703中存储的程序指令。所述至少一个存储器1703中的至少一个也可以包括于处理器1702中。本申请实施例中不限定上述通信接口1701、处理器1702以及存储器1703之间的连接介质。例如，本申请实施例在图17中以存储器1703、处理器1702以及通信接口1701之间可以通过总线连接，所述总线可以分为地址总线、数据总线、控制总线等。In the embodiment of the present application, the communication interface 1701 may be a transceiver, a circuit, a bus, a module, or other types of communication interfaces. The processor 1702 may be a general-purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, and may implement or execute the The disclosed methods, steps and logic block diagrams. The general-purpose processor may be a microprocessor or any conventional processor or the like. The steps of the method disclosed in combination with the embodiments of the present application may be directly embodied as being executed and completed by a hardware processor, or executed and completed by a combination of hardware and software modules in the processor. The memory 1703 may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), etc., and may also be a volatile memory, such as random access memory (random access memory). -access memory, RAM). The memory is any other medium that can be used to carry or store desired program codes in the form of instructions or data structures and that can be accessed by a computer, but is not limited to this. The memory in the embodiment of the present application may also be a circuit or any other device capable of realizing a storage function. The memory 1703 is coupled with the processor 1702. The coupling in the embodiments of the present application is an interval coupling or a communication connection between devices, units or modules, which can be electrical, mechanical or other forms, and is used for information exchange between devices, units or modules. As another implementation, the memory 1703 may also be located outside the apparatus 1700. The processor 1702 may cooperate with the memory 1703 to operate. The processor 1702 may execute program instructions stored in the memory 1703. At least one of the at least one memory 1703 may also be included in the processor 1702. The embodiment of the present application does not limit the connection medium between the communication interface 1701, the processor 1702, and the memory 1703. For example, in the embodiment of the present application in FIG. 17, the memory 1703, the processor 1702, and the communication interface 1701 may be connected by a bus, and the bus may be divided into an address bus, a data bus, and a control bus.

可以理解的，上述图16所示实施例中的装置可以以图17所示的装置1700实现。具体的，处理单元1601可以由处理器1702实现，收发单元1602可以由通信接口1701实现。It can be understood that the apparatus in the embodiment shown in FIG. 16 may be implemented by the apparatus 1700 shown in FIG. 17. Specifically, the processing unit 1601 may be implemented by the processor 1702, and the transceiver unit 1602 may be implemented by the communication interface 1701.

本申请实施例还提供一种计算机可读存储介质，该计算机可读存储介质存储有计算机程序，当该计算机程序在设备上运行时，使得设备执行上述各个实施例所示的方法。The embodiments of the present application also provide a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program runs on a device, the device executes the methods shown in each of the foregoing embodiments.

本申请实施例还提供一种通信***，该通信***包括会话功能管理网元和第一网元，其中第一网元可以为DNS代理、或地址解析功能网元、或集中DNS服务器中的任意一种。An embodiment of the present application also provides a communication system, which includes a session function management network element and a first network element, where the first network element may be any of a DNS proxy, an address resolution function network element, or a centralized DNS server A sort of.

本申请实施例提供的方法中，可以全部或部分地通过软件、硬件、固件或者其任意组合来实现。当使用软件实现时，可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令。在计算机上加载和执行所述计算机程序指令时，全部或部分地产生按照本发明实施例所述的流程或功能。所述计算机可以是通用计算机、专用计算机、计算机网络、网络设备、用户设备或者其他可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输，例如，所述计算机指令可以从一个网站站点、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、数字用户线(digital subscriber line，简称DSL))或无线(例如红外、无线、微波等)方式向另一个网站站点、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机可以存取的任何可用介质或者是包含一个或多个可用介质集成的服务器、数据中心等数据存储设备。所述可用介质可以是磁性介质(例如，软盘、硬盘、磁带)、光介质(例如，数字视频光盘(digital video disc，简称DVD))、或者半导体介质(例如,固态硬盘Solid State Disk SSD)等。The methods provided in the embodiments of the present application may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented by software, it can be implemented in the form of a computer program product in whole or in part. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the processes or functions described in the embodiments of the present invention are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, network equipment, user equipment, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center. Transmission to another website, computer, server or data center via wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or a data center integrated with one or more available media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, and a magnetic tape), an optical medium (for example, a digital video disc (digital video disc, DVD for short)), or a semiconductor medium (for example, a solid state disk Solid State Disk SSD), etc. .

以上所述，以上实施例仅用以对本申请的技术方案进行了详细介绍，但以上实施例的说明只是用于帮助理解本发明实施例的方法，不应理解为对本发明实施例的限制。本技术领域的技术人员可轻易想到的变化或替换，都应涵盖在本发明实施例的保护范围之内。As mentioned above, the above embodiments are only used to introduce the technical solutions of the present application in detail, but the description of the above embodiments is only used to help understand the methods of the embodiments of the present invention, and should not be construed as limiting the embodiments of the present invention. Any changes or replacements that can be easily conceived by those skilled in the art should be covered by the protection scope of the embodiments of the present invention.

Claims

一种发现应用的方法，其特征在于，该方法包括：A method for discovering applications, characterized in that the method includes:

会话管理功能网元获取第一信息，所述第一信息包括第一域名对应的第一应用的标识和所述第一应用所在的至少一个应用平台的位置信息；The session management function network element obtains first information, where the first information includes the identifier of the first application corresponding to the first domain name and the location information of at least one application platform on which the first application is located;

所述会话管理功能网元至少根据所述第一信息和终端设备的位置信息确定第二信息；所述第二信息用于获取所述第一域名对应的第一IP地址；The session management function network element determines second information at least according to the first information and the location information of the terminal device; the second information is used to obtain the first IP address corresponding to the first domain name;

所述会话管理功能网元向第一用户面网元发送所述第一域名和所述第二信息。The session management function network element sends the first domain name and the second information to a first user plane network element.
如权利要求1所述的方法，其特征在于，所述会话管理功能网元至少根据第一信息和终端设备的位置信息确定第二信息，包括：The method according to claim 1, wherein the session management function network element determines the second information at least according to the first information and the location information of the terminal device, comprising:

所述会话管理功能网元根据所述第一信息和所述终端设备的位置信息，在所述第一应用所在的至少一个应用平台中确定第一应用平台；所述第二信息与所述第一应用平台对应。The session management function network element determines a first application platform in at least one application platform where the first application is located according to the first information and the location information of the terminal device; the second information is related to the first application platform. One application platform corresponds.
如权利要求1或2所述的方法，其特征在于，所述第一应用所在的至少一个应用平台的位置信息包括所述第一应用所在的至少一个应用平台分别对应的数据网络接入标识DNAI。The method according to claim 1 or 2, wherein the location information of the at least one application platform where the first application is located includes the data network access identifier DNAI corresponding to the at least one application platform where the first application is located. .
如权利要求2或3所述的方法，其特征在于，所述第二信息包括所述第一应用平台对应的DNAI。The method according to claim 2 or 3, wherein the second information includes DNAI corresponding to the first application platform.
如权利要求2或3所述的方法，其特征在于，所述第一信息还包括：所述第一应用所在的至少一个应用平台分别对应的IP地址；The method according to claim 2 or 3, wherein the first information further comprises: IP addresses respectively corresponding to at least one application platform on which the first application is located;

所述会话管理功能网元根据所述第一应用平台和所述第一应用所在的至少一个应用平台分别对应的IP地址确定所述第二信息，所述第二信息包括所述第一应用平台对应的IP地址。The session management function network element determines the second information according to the IP addresses respectively corresponding to the first application platform and the at least one application platform on which the first application is located, where the second information includes the first application platform The corresponding IP address.
如权利要求2或3所述的方法，其特征在于，所述第一信息还包括所述第一应用所在的至少一个应用平台分别对应的本地域名***DNS服务器的IP地址；The method according to claim 2 or 3, wherein the first information further includes the IP addresses of local domain name system DNS servers respectively corresponding to at least one application platform on which the first application is located;

所述会话管理功能网元根据所述第一应用平台和所述第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址确定所述第二信息，所述第二信息包括第一本地DNS服务器的IP地址，其中，所述第一本地DNS服务器为所述第一应用平台提供服务。The session management function network element determines the second information according to the IP address of the local DNS server corresponding to the first application platform and the at least one application platform on which the first application is located, and the second information includes the first application platform. The IP address of the local DNS server, where the first local DNS server provides services for the first application platform.
如权利要求3所述的方法，其特征在于，所述第一信息还包括所述第一应用所在的至少一个应用平台分别对应的索引信息；The method according to claim 3, wherein the first information further includes index information corresponding to at least one application platform where the first application is located;

所述方法还包括：The method also includes:

所述会话管理功能网元根据所述第一信息确定第三信息；所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的DNAI与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系；The session management function network element determines third information according to the first information; the third information includes DNAIs corresponding to at least one application platform where the first application is located and at least one application where the first application is located. Correspondence of index information corresponding to each platform;

所述会话管理功能网元向所述第一用户面网元发送所述第三信息；Sending, by the session management function network element, the third information to the first user plane network element;

所述会话管理功能网元根据所述第一应用平台的DNAI和所述第一应用所在的至少一个应用平台分别对应的索引信息确定第二信息，所述第二信息包括所述第一应用平台对应的DNAI对应的索引信息。The session management function network element determines second information according to the index information corresponding to the DNAI of the first application platform and the at least one application platform where the first application is located, and the second information includes the first application platform Index information corresponding to the corresponding DNAI.
如权利要求2或3所述的方法，其特征在于，所述第一信息还包括所述第一应用所在的至少一个应用平台分别对应的索引信息和所述第一应用所在的至少一个应用平台分别对应的IP地址；The method according to claim 2 or 3, wherein the first information further includes index information corresponding to at least one application platform on which the first application is located and at least one application platform on which the first application is located. Corresponding IP address;

所述方法还包括：The method also includes:

所述会话管理功能网元根据所述第一信息确定第三信息；所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的IP地址与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系；The session management function network element determines third information according to the first information; the third information includes at least one of an IP address corresponding to at least one application platform where the first application is located and at least one where the first application is located Correspondence of index information corresponding to application platforms;

所述会话管理功能网元向所述第一用户面网元发送所述第三信息；Sending, by the session management function network element, the third information to the first user plane network element;

所述会话管理功能网元根据所述第一应用平台、所述第一应用所在的至少一个应用平台分别对应的IP地址和所述第一应用所在的至少一个应用平台分别对应的索引信息确定所述第二信息，所述第二信息包括所述第一应用平台对应的IP地址对应的索引信息。The session management function network element determines the corresponding IP address respectively corresponding to the first application platform, the at least one application platform where the first application is located, and the index information corresponding to the at least one application platform where the first application is located. The second information includes index information corresponding to the IP address corresponding to the first application platform.
如权利要求2或3所述的方法，其特征在于，所述第一信息还包括所述第一应用所在的至少一个应用平台分别对应的索引信息和所述第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址；The method according to claim 2 or 3, wherein the first information further includes index information corresponding to at least one application platform on which the first application is located and at least one application platform on which the first application is located. The IP address of the corresponding local DNS server;

所述方法还包括：The method also includes:

所述会话管理功能网元根据所述第一信息确定第三信息；所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系；The session management function network element determines third information according to the first information; the third information includes the IP address of the local DNS server corresponding to the at least one application platform on which the first application is located and the first application Correspondence of index information corresponding to at least one application platform;

所述会话管理功能网元向所述第一用户面网元发送所述第三信息；Sending, by the session management function network element, the third information to the first user plane network element;

所述会话管理功能网元根据所述第一应用平台、所述第一应用所在的至少一个应用平台分别对应的索引信息和所述第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址确定所述第二信息，所述第二信息包括第一本地DNS服务器的IP地址对应的索引信息，其中，所述第一本地DNS服务器为所述第一应用平台提供服务。The session management function network element is based on the index information corresponding to the first application platform, the at least one application platform where the first application is located, and the local DNS server corresponding to the at least one application platform where the first application is located. The IP address determines the second information, and the second information includes index information corresponding to the IP address of the first local DNS server, where the first local DNS server provides services for the first application platform.
如权利要求1-9任一项所述的方法，其特征在于，还包括：The method according to any one of claims 1-9, further comprising:

所述会话管理功能网元向第一用户面网元发送第一指示信息；Sending, by the session management function network element, the first indication information to the first user plane network element;

所述第一指示信息用于指示所述第一用户面网元在接收到来自于所述终端设备的第一请求且所述第一请求包括所述第一域名时，根据所述第二信息确定第二请求，并将所述第二请求发送至第一DNS服务器。The first indication information is used to indicate that the first user plane network element receives a first request from the terminal device and the first request includes the first domain name, according to the second information Determine the second request, and send the second request to the first DNS server.
如权利要求1-10任一项所述的方法，其特征在于，还包括：The method according to any one of claims 1-10, further comprising:

所述会话管理功能网元接收来自于所述第一用户面网元的第四信息，所述第四信息包括所述第一应用所在的第二应用平台对应的DNAI、所述第一应用所在的第二应用平台对应的IP地址、所述第一IP地址中的至少一种；所述第一IP地址为部署在所述第二应用平台上的所述第一应用的服务器的IP地址；The session management function network element receives fourth information from the first user plane network element, where the fourth information includes DNAI corresponding to the second application platform where the first application is located, and where the first application is located. At least one of the IP address corresponding to the second application platform and the first IP address; the first IP address is the IP address of the server of the first application deployed on the second application platform;

所述会话管理功能网元基于所述第四信息为所述终端设备的PDU会话选择本地PDU会话锚点以及选择上行分类器ULCL或分支点BP。The session management function network element selects a local PDU session anchor point and an uplink classifier ULCL or branch point BP for the PDU session of the terminal device based on the fourth information.
如权利要求1-11任一项所述的方法，其特征在于，所述方法还包括：The method according to any one of claims 1-11, wherein the method further comprises:

所述会话管理功能网元根据所述第一信息和更新后的所述终端设备的位置信息，在所述至少一个应用平台中确定第三应用平台；Determining, by the session management function network element, a third application platform among the at least one application platform according to the first information and the updated location information of the terminal device;

所述会话管理功能网元向所述第一用户面网元发送所述第一域名和更新后的第二信息，所述更新后的第二信息与所述第三应用平台对应；Sending, by the session management function network element, the first domain name and updated second information to the first user plane network element, where the updated second information corresponds to the third application platform;

所述会话管理功能网元接收来自于所述第一用户面网元的通知消息，所述通知消息用于指示所述会话管理功能网元向所述终端设备发送非接入层NAS消息，所述NAS消息包括所述第一域名。The session management function network element receives a notification message from the first user plane network element, where the notification message is used to instruct the session management function network element to send a non-access stratum NAS message to the terminal device, so The NAS message includes the first domain name.
一种发现应用的方法，其特征在于，该方法包括：A method for discovering applications, characterized in that the method includes:

第一用户面网元接收来自于会话管理功能网元的第一域名和第二信息，所述第二信息由会话管理功能网元至少根据终端设备的位置信息所确定；所述终端设备的位置信息指示所述终端设备处于第一位置；The first user plane network element receives the first domain name and second information from the session management function network element, the second information is determined by the session management function network element at least according to the location information of the terminal device; the location of the terminal device The information indicates that the terminal device is in the first position;

所述第一用户面网元接收来自于所述终端设备的第一请求，所述第一请求包括所述第一域名；Receiving, by the first user plane network element, a first request from the terminal device, the first request including the first domain name;

所述第一用户面网元根据所述第二信息确定第二请求，并向第一DNS服务器发送所述第二请求，所述第二请求用于在所述终端设备位于所述第一位置时获取所述第一域名对应的第一IP地址。The first user plane network element determines a second request according to the second information, and sends the second request to a first DNS server, where the second request is used when the terminal device is located at the first position When obtaining the first IP address corresponding to the first domain name.
如权利要求13所述的方法，其特征在于，所述第二信息包括第一应用平台对应的DNAI，所述第一应用所在的至少一个应用平台包括所述第一应用平台。The method of claim 13, wherein the second information includes a DNAI corresponding to a first application platform, and at least one application platform on which the first application is located includes the first application platform.
如权利要求13所述的方法，其特征在于，所述第二信息包括第一应用平台对应的IP地址，所述第一应用所在的至少一个应用平台包括所述第一应用平台。The method according to claim 13, wherein the second information includes an IP address corresponding to a first application platform, and at least one application platform on which the first application is located includes the first application platform.
如权利要求13所述的方法，其特征在于，所述第二信息包括第一本地DNS服务器的IP地址，其中，所述第一本地DNS服务器为第一应用平台提供服务，所述第一应用所在的至少一个应用平台包括所述第一应用平台。The method of claim 13, wherein the second information includes the IP address of the first local DNS server, wherein the first local DNS server provides services for the first application platform, and the first application The at least one application platform where it is located includes the first application platform.
如权利要求13所述的方法，其特征在于，所述第二信息包括第一应用平台对应的DNAI对应的索引信息，所述第一应用所在的至少一个应用平台包括所述第一应用平台；The method according to claim 13, wherein the second information includes index information corresponding to DNAI corresponding to a first application platform, and at least one application platform on which the first application is located includes the first application platform;

所述方法还包括：The method also includes:

所述第一用户面网元接收来自于所述会话管理功能网元的第三信息；所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的DNAI与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系。The first user plane network element receives third information from the session management function network element; the third information includes DNAI and the first application respectively corresponding to at least one application platform where the first application is located Correspondence of index information corresponding to at least one application platform.
如权利要求13所述的方法，其特征在于，所述第二信息包括第一应用平台对应的IP地址对应的索引信息，所述第一应用所在的至少一个应用平台包括所述第一应用平台；The method according to claim 13, wherein the second information includes index information corresponding to the IP address corresponding to the first application platform, and at least one application platform on which the first application is located includes the first application platform ；

所述方法还包括：The method also includes:

所述第一用户面网元接收来自于所述会话管理功能网元的第三信息；所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的IP地址与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系。The first user plane network element receives third information from the session management function network element; the third information includes an IP address corresponding to at least one application platform on which the first application is located and the first Correspondence of index information corresponding to at least one application platform where the application is located.
如权利要求13所述的方法，其特征在于，所述第二信息包括第一本地DNS服务器的IP地址对应的索引信息，其中，所述第一本地DNS服务器为第一应用平台提供服务，所述第一应用所在的至少一个应用平台包括所述第一应用平台；The method according to claim 13, wherein the second information includes index information corresponding to the IP address of the first local DNS server, wherein the first local DNS server provides services for the first application platform, so The at least one application platform on which the first application is located includes the first application platform;

所述方法还包括：The method also includes:

所述第一用户面网元接收来自于所述会话管理功能网元的第三信息；所述第三信息包括所述第一应用所在的至少一个应用平台分别对应的本地DNS服务器的IP地址与所述第一应用所在的至少一个应用平台分别对应的索引信息的对应关系。The first user plane network element receives third information from the session management function network element; the third information includes the IP addresses and IP addresses of local DNS servers respectively corresponding to at least one application platform on which the first application is located Correspondence of index information corresponding to at least one application platform on which the first application is located.
如权利要求13-19任一项所述的方法，其特征在于，还包括：The method according to any one of claims 13-19, further comprising:

所述第一用户面网元接收来自于所述会话管理功能网元的第一指示信息；Receiving, by the first user plane network element, first indication information from the session management function network element;

所述第一指示信息用于指示所述第一用户面网元在接收到来自于所述终端设备的第一请求且所述第一请求包括所述第一域名时，根据所述第二信息确定第二请求，并将所述第二请求发送至第一DNS服务器。The first indication information is used to indicate that when the first user plane network element receives a first request from the terminal device and the first request includes the first domain name, according to the second information Determine the second request, and send the second request to the first DNS server.
如权利要求14或17或20所述的方法，其特征在于，所述第一用户面网元根据所述第二信息确定第二请求，并将所述第二请求发送至第一DNS服务器，包括：The method according to claim 14 or 17 or 20, wherein the first user plane network element determines a second request according to the second information, and sends the second request to the first DNS server, include:

所述第一用户面网元将所述第一应用平台对应的DNAI添加至所述第一请求，获得第二请求，并将所述第二请求发送至所述第一DNS服务器，所述第一DNS服务器为集中DNS服务器。The first user plane network element adds the DNAI corresponding to the first application platform to the first request, obtains a second request, and sends the second request to the first DNS server. A DNS server is a centralized DNS server.
如权利要求15或18或20所述的方法，其特征在于，所述第一用户面网元根据所述第二信息确定第二请求，并将所述第二请求发送至第一DNS服务器，包括：The method according to claim 15 or 18 or 20, wherein the first user plane network element determines a second request according to the second information, and sends the second request to the first DNS server, include:

所述第一用户面网元将所述第一应用平台对应的IP地址添加至所述第一请求，获得第二请求，并将所述第二请求发送至所述第一DNS服务器，所述第一DNS服务器为集中DNS服务器。The first user plane network element adds the IP address corresponding to the first application platform to the first request, obtains a second request, and sends the second request to the first DNS server, and The first DNS server is a centralized DNS server.
如权利要求16或19或20所述的方法，其特征在于，所述第一用户面网元根据所述第二信息确定第二请求，并将所述第二请求发送至第一DNS服务器，包括：The method according to claim 16 or 19 or 20, wherein the first user plane network element determines a second request according to the second information, and sends the second request to the first DNS server, include:

所述第一用户面网元将所述第一请求的目标地址修改为所述第一本地DNS服务器的IP地址，获得第二请求，并将所述第二请求发送至所述第一DNS服务器，所述第一DNS服务器为所述第一本地DNS服务器。The first user plane network element modifies the target address of the first request to the IP address of the first local DNS server, obtains a second request, and sends the second request to the first DNS server , The first DNS server is the first local DNS server.
如权利要求13-23任一项所述的方法，其特征在于，还包括：The method according to any one of claims 13-23, further comprising:

所述第一用户面网元向所述会话管理功能网元发送第四信息，所述第四信息包括所述第一应用所在的第二应用平台对应的DNAI、所述第一应用所在的第二应用平台对应的IP地址、所述第一IP地址中的至少一种；其中，所述第一IP地址为部署在所述第二应用平台上的所述第一应用的服务器的IP地址。The first user plane network element sends fourth information to the session management function network element, where the fourth information includes DNAI corresponding to the second application platform where the first application is located, and the first application where the first application is located. 2. At least one of an IP address corresponding to an application platform and the first IP address; wherein the first IP address is an IP address of a server of the first application deployed on the second application platform.
如权利要求13-24任一项所述的方法，其特征在于，还包括：The method according to any one of claims 13-24, further comprising:

所述第一用户面网元接收来自于所述会话管理功能网元的所述第一域名和更新后的第二信息，所述更新后的第二信息与所述第三应用平台对应；Receiving, by the first user plane network element, the first domain name and updated second information from the session management function network element, where the updated second information corresponds to the third application platform;

所述第一用户面网元向所述会话管理功能网元发送通知消息，所述通知消息用于指示所述会话管理功能网元向所述终端设备发送NAS消息，所述NAS消息包括所述第一域名。The first user plane network element sends a notification message to the session management function network element, where the notification message is used to instruct the session management function network element to send a NAS message to the terminal device, and the NAS message includes the The first domain name.
如权利要求25所述的方法，其特征在于，还包括：The method of claim 25, further comprising:

在所述第一用户面网元向所述会话管理功能网元发送所述通知消息之前，所述第一用户面网元确定所述第一域名对应的DNS缓存记录的存留时间TTL未超过预设时长。Before the first user plane network element sends the notification message to the session management function network element, the first user plane network element determines that the retention time TTL of the DNS cache record corresponding to the first domain name does not exceed the preset value. Set the duration.
一种发现应用的装置，其特征在于，该装置包括：A device for discovering applications, characterized in that the device includes:

处理单元获取第一信息，所述第一信息包括第一域名对应的第一应用的标识和所述第一应用所在的至少一个应用平台的位置信息；The processing unit obtains first information, where the first information includes the identifier of the first application corresponding to the first domain name and the location information of at least one application platform on which the first application is located;

所述处理单元用于至少根据第一信息和终端设备的位置信息确定第二信息；所述第二信息用于获取所述第一域名对应的第一IP地址；The processing unit is used to determine second information at least according to the first information and the location information of the terminal device; the second information is used to obtain the first IP address corresponding to the first domain name;

所述发送单元用于向第一用户面网元发送所述第一域名和所述第二信息。The sending unit is configured to send the first domain name and the second information to a first user plane network element.
一种发现应用的装置，其特征在于，该装置包括：A device for discovering applications, characterized in that the device includes:

接收单元，用于接收来自于会话管理功能网元的第一域名和第二信息，所述第二信息由会话管理功能网元至少根据终端设备的位置信息所确定；所述终端设备的位置信息指示所述终端设备处于第一位置；The receiving unit is configured to receive the first domain name and second information from the session management function network element, where the second information is determined by the session management function network element at least according to the location information of the terminal device; the location information of the terminal device Indicating that the terminal device is in the first position;

所述接收单元，用于接收来自于所述终端设备的第一请求，所述第一请求包括所述第一域名；The receiving unit is configured to receive a first request from the terminal device, where the first request includes the first domain name;

处理单元，用于根据所述第二信息确定第二请求，并向第一DNS服务器发送所述第二请求，所述第二请求用于在所述终端设备位于所述第一位置时获取所述第一域名对应的第一IP地址。The processing unit is configured to determine a second request according to the second information, and send the second request to the first DNS server, where the second request is used to obtain the information when the terminal device is located in the first position. The first IP address corresponding to the first domain name.
一种设备，其特征在于，所述设备包括收发器、处理器和存储器；所述存储器中存储有程序指令；当所述程序指令被执行时，使得所述设备执行如权利要求1至26任一所述的方法。A device, characterized in that the device includes a transceiver, a processor, and a memory; program instructions are stored in the memory; when the program instructions are executed, the device executes any of claims 1 to 26 One described method.
一种芯片，其特征在于，所述芯片与电子设备中的存储器耦合，使得所述芯片在运行时调用所述存储器中存储的程序指令，实现如权利要求1至26任一所述的方法。A chip, characterized in that the chip is coupled with a memory in an electronic device, so that the chip invokes program instructions stored in the memory during operation to implement the method according to any one of claims 1 to 26.
一种计算机可读存储介质，其特征在于，所述计算机可读存储介质存储有程序指令，当所述程序指令在设备上运行时，使得所述设备执行如权利要求1至26任一项所述的方法。A computer-readable storage medium, wherein the computer-readable storage medium stores program instructions, when the program instructions run on a device, the device executes any one of claims 1 to 26 The method described.
一种通信***，其特征在于，该***包括：会话管理功能网元和第一用户面网元；所述会话管理功能网元执行如权利要求1-12任一项所述的方法，所述第一用户面网元执行如权利要求13-26任一项所述的方法。A communication system, characterized in that the system comprises: a session management function network element and a first user plane network element; the session management function network element executes the method according to any one of claims 1-12, and The first user plane network element executes the method according to any one of claims 13-26.