CN113727325A

CN113727325A - Session processing method and related equipment

Info

Publication number: CN113727325A
Application number: CN202111048229.9A
Authority: CN
Inventors: 宋依欣; 郑伟; 林文通; 杨骏泽; 王旗; 张孟康
Original assignee: China Telecom Corp Ltd
Current assignee: China Telecom Corp Ltd
Priority date: 2021-09-08
Filing date: 2021-09-08
Publication date: 2021-11-30
Anticipated expiration: 2041-09-08
Also published as: CN113727325B

Abstract

The disclosure provides a session processing method, an access mobility management network element, an electronic device and a storage medium. The session processing method is executed by an access mobility management network element AMF, and comprises the following steps: receiving a session establishment request sent by user equipment; determining a home location session management network element SMF according to the session establishment request; taking SMF of a roaming place supporting the capability of an intermediate session management network element iSMF as the iSMF; accessing the home SMF through the iSMF to establish a session connection. The session processing method can improve the security and the flexibility of the session.

Description

Session processing method and related equipment

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a session processing method, an access mobility management network element, an electronic device, and a storage medium.

Background

The wireless VPDN (Virtual Private dial-up Network) service is a Virtual Private Network isolated from the public internet and constructed for clients by using L2TP and GRE tunneling techniques. The service becomes the choice of wireless internet access of most enterprises with the advantages of wide coverage, high safety, high speed and the like.

With the advent of the 5G era, especially the gradual commercialization of 5G SA networks, the large-scale adjustment of wireless network architecture brings a great challenge to the security of emerging information of the internet. Due to the mobility of wireless network users, when the VPDN users roam between provinces, the 5G SA network inquires the SMF of the province where the users belong through the NRF based on the province label in the DNN, so that the user service is routed to the province where the users belong, and the normal use of the wireless VPDN service is guaranteed. The process of service routing involves a session management network element SMF and an egress gateway UPF in the roaming province, and SMF and UPF in the home province.

In the existing 5G SA network, no means is provided for well controlling the access of the SMF selected by the user in the scene. And the home provincial SMF directly communicates with the roaming provincial SMF accessed by the user to transmit the signaling. This process presents risks and concerns.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The present disclosure is directed to a session processing method, an access mobility management network element, an electronic device, and a storage medium, where the session processing method can improve security and flexibility of a session.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows, or in part will be obvious from the description, or may be learned by practice of the disclosure.

The embodiment of the present disclosure provides a session processing method, where the method is executed by an access mobility management element (AMF), and the method includes: receiving a session establishment request sent by user equipment; determining a home location session management network element SMF according to the session establishment request; taking SMF of a roaming place supporting the capability of an intermediate session management network element iSMF as the iSMF; accessing the home SMF through the iSMF to establish a session connection.

In some exemplary embodiments of the present disclosure, regarding a roaming place SMF supporting an intermediate session management network element imsf capability as an imsf, the method includes: sending a session context request to the randomly selected SMF; if receiving a message which is returned by the randomly selected SMF and supports the iSMF as the iSMF, recording and updating an iSMF supporting capability parameter corresponding to the randomly selected SMF; and if receiving a message which is returned by the randomly selected SMF and does not support the message as the iSMF, randomly selecting the SMF again, and sending the session context request to the newly selected SMF.

In some exemplary embodiments of the present disclosure, regarding a roaming place SMF supporting an intermediate session management network element imsf capability as an imsf, the method includes: the roaming-place SMF that supports the immf capability parameter yes is selected as the immf.

In some exemplary embodiments of the present disclosure, a parameter is configured on the SMF for specifying whether the SMF supports the capability as an iSMF.

In some exemplary embodiments of the present disclosure, the session establishment request includes a data network name DNN parameter, a first tracking area identification TAI, and a single network slice selection assistance information S-NSSAI parameter; wherein, determining a home session management network element SMF according to the session establishment request includes: replacing the first tracking area identity TAI with a second tracking area identity TAI; sending the DNN parameter, the second tracking area identification TAI and the S-NSSAI parameter to a roaming location network storage network element (LNRF) so that the LNRF sends the DNN parameter, the second tracking area identification TAI and the S-NSSAI parameter to a total network storage network element (HNRF), the HNRF determines the home SMF according to the DNN parameter and the S-NSSAI parameter, and returns the home SMF information to the LNRF; and receiving the home SMF information returned by the LNRF, and storing the home SMF information into a cache list.

In some exemplary embodiments of the present disclosure, the home session management network element SMF is determined according to the session establishment request, and the method further includes: and matching and obtaining the home SMF from the cache list according to the first tracking area identification TAI and the S-NSSAI parameter.

In some exemplary embodiments of the present disclosure, the session establishment request comprises a data network name, DNN, parameter and a first tracking area identification, TAI; wherein accessing the home SMF through the iSMF to establish a session connection comprises: and sending the DNN parameter and the first tracking area identification TAI to the home SMF, so that the home SMF obtains a middle user plane function network element UPF through the first tracking area identification TAI matching, and obtains a home UPF through the DNN parameter matching.

The embodiment of the present disclosure provides an access mobility management element AMF, including: the device comprises a request receiving module, a session establishing module and a service module, wherein the request receiving module is used for receiving a session establishing request sent by user equipment, and the session establishing request comprises a Data Network Name (DNN) parameter; an SMF determining module, configured to determine a home session management network element SMF according to the session establishment request; the system comprises an iSMF determining module, a network element management module and a network element management module, wherein the iSMF determining module is used for taking a roaming place SMF supporting the capability of an intermediate session management network element iSMF as the iSMF; and the session establishing module is used for sending the session establishing request to the home SMF through the iSMF so as to establish session connection.

An embodiment of the present disclosure provides an electronic device, including: at least one processor; a storage terminal device for storing at least one program which, when executed by at least one processor, causes the at least one processor to implement any one of the session processing methods described above.

The disclosed embodiment provides a computer readable storage medium, on which a computer program is stored, wherein the computer program is used for implementing any one of the above-mentioned session processing methods when being executed by a processor.

According to the session processing method provided by the embodiment of the disclosure, aiming at the problem of regression of data and signaling when a provincial roaming VPDN user accesses, the AMF can select a roaming place SMF supporting the iSMF capability as the iSMF, and accesses the home SMF through the selected iSMF, so that the security of the session can be improved, and the risk of information leakage caused by direct interconnection of the local SMF and the home provincial SMF in the prior art is reduced to a great extent; when the AMF selects the SMF, whether the SMF supports the capability of being used as the iSMF needs to be examined, so that an access management and control strategy taking a user as granularity is formed on the SMF, and the safety and the flexibility of the SMF network element maintenance are improved. In addition, the method adds SMF selection strategy configuration in the existing network element and introduces a strategy of whether to support the capability of the iSMF, the method does not need to modify the user authentication flow of the 5G wireless VPDN of the existing network, and can be realized by simply configuring and upgrading the existing AMF and SMF equipment.

The session processing method provided by the embodiment of the disclosure can be applied to VPDN services under a 5G SA network, and particularly can realize the process of safely and reliably routing the services to the province of the home country when the VPDN users roaming across the provinces in China use the services in different places.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.

FIG. 1 is a flow diagram illustrating a session processing method in accordance with an exemplary embodiment.

FIG. 2 is a schematic diagram illustrating a session handling system interaction in accordance with an illustrative embodiment.

Fig. 3 is a diagram illustrating a 5G SA wireless VPDN inter-province roaming user access and home province SMF capability determination process according to an example embodiment.

Fig. 4 is a block diagram illustrating an access mobility management network element in accordance with an example embodiment.

Fig. 5 is a schematic structural diagram of an electronic device according to an exemplary embodiment.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repetitive description will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and/or processor terminal devices and/or microcontroller terminal devices.

Hereinafter, each step of the session processing method in the exemplary embodiment of the present disclosure will be described in more detail with reference to the drawings and the embodiments.

FIG. 1 is a flow diagram illustrating a session processing method in accordance with an exemplary embodiment. The method provided in the embodiment of the present disclosure may be executed by an Access and Mobility Management Function (AMF), but the present disclosure is not limited thereto.

The AMF may be an AMF of a roaming place.

As shown in fig. 1, a session processing method provided by the embodiment of the present disclosure may include the following steps.

In step S102, a session establishment request sent by the user equipment is received.

In the embodiment of the present disclosure, a user of a VPDN (Virtual Private Dial Network) roaming in a province across may carry access point DNN information, initiate an access request to a 5G Network in the province roaming, and after receiving the access request, the 5G Network in the province roaming may return registration success information.

In the embodiment of the present disclosure, the user equipment (or the terminal device) may send a session establishment request to the AMF, and the AMF may receive the session establishment request.

In an exemplary embodiment, the session establishment request may include a DNN (Data Network Name) parameter, a first TAI (Tracking Area Identity) and an S-NSSAI (Single Network Slice Selection Assistance Information) parameter.

The TAI parameter may be used to define the location of the user.

In step S104, a Session Management Function (Session Management network element) is determined according to the Session establishment request.

In the embodiment of the present disclosure, the AMF may search whether there is a matching SMF according to the DNN parameter in the session establishment request. If the user is a primary request, the AMF may not be matched with a proper SMF in the cache list through DNN carried by the terminal; the AMF can be determined by the following method.

In an exemplary embodiment, the first tracking area identification TAI may be replaced by a second tracking area identification TAI; the DNN parameter, the second tracking area identification TAI and the S-NSSAI parameter are sent to a roaming place network storage network element LNRF, so that the LNRF sends the DNN parameter, the second tracking area identification TAI and the S-NSSAI parameter to a total network storage network element HNRF, the HNRF determines a home SMF according to the DNN parameter and the S-NSSAI parameter, and returns the home SMF information to the LNRF; and receiving the home SMF information returned by the LNRF, and storing the home SMF information into a cache list.

The first tracking area identity TAI may be a TAI carried in the session establishment request, and the second tracking area identity TAI may be a preferred-TAI. Wherein, the TAI is replaced by the preferred-TAI, only the name of the parameter is replaced, and the carried parameter is not changed. The purpose of replacing the TAI with a preferred-TAI is to enable subsequent LNRFs to strip out this parameter to find a matching home SMF (also known as hSMF).

The roaming-place network storage network element LNRF can be a roaming-province network storage network element, the total network storage network element HNRF can be a national network storage network element, the roaming-province network storage network element is only configured with DNN of the province, and the national network storage network element is configured with DNN of the country.

In the embodiment of the disclosure, a capability switch may be set on the AMF to support the selection of the immf. After the switch is opened, the AMF supports an iSMF selection function, and the iSMF can be used for being inserted between the SMF and the AMF and is responsible for controlling iUPF which cannot be directly controlled by the SMF. At this point, the AMF that supports the ability to select an imsf will replace tai with preferred-tai in selecting the appropriate SMF, and pass it to the roaming province LNRF.

Since the roaming province LNRF is configured with only the DNN of the province, the LNRF may pass the parameters to the HNRF, since the DNN, the preferred-TAI, and the S-NSSAI cannot match up with the corresponding SMF. HNRF can assign a Home province SMF, hSMF, to AMF via DNN, and S-NSSAI. At this time, the LNRF of the home province may report a network element search result message, where the message carries a "preferredteamatchind: false" field, which indicates that the SMF is matched without using the preferred-tai parameter. The AMF may cache information for the hSMF that the LNRF matches.

In an exemplary embodiment, the AMF may obtain the home SMF from the cache list according to the first tracking area identification TAI and S-NSSAI parameters.

That is, if the user is a primary request, the AMF determines the home SMF by the above method, and caches the information of the home SMF to the lower side; if the user is not the initial request, the AMF may match a suitable SMF from the cache list through the DNN carried by the terminal.

In step S106, the roaming-place SMF that supports the capability of the intermediate session management network element immf is taken as the immf.

In the embodiment of the disclosure, the AMF may select an SMF that supports the imsf capability from the SMFs in the roaming area as an intermediate SMF (i.e., an imsf). The imsf may be used to interpose between the SMF and the AMF, taking care of controlling the iUPF which cannot be directly controlled by the SMF.

In the embodiment of the disclosure, a parameter for specifying whether the SMF supports the capability as the insmf is configured on the SMF.

For example, an SMF selection policy (SMFSELPLCY) configuration is added to the SMF network element and a "whether or not to support as an imsf capability" parameter is added that specifies whether or not the SMF supports as an imsf capability interposed between the SMF and the AMF. When the parameter is "YES", the configuration is such that the capability is possessed, whereas "NO" is set, and "NO" is set as a default value.

In the session establishment process, the AMF may cache the information of the SMF in a local list, and synchronously record and update a parameter on the SMF as to whether the SMF is supported as an smsf capability.

When the selection policy of the AMF is configured with the capability of supporting selection of the iSMF, it will use "whether to support as the iSMF capability" as the criterion for selecting the SMF when the AMF initiates local TOPO discovery. If the capability is configured as "NO" on a SMF in the roaming province, that SMF is not selected as an iSMF.

In an exemplary embodiment, whether an SMF has the capability to support an insmf may be determined by the following method.

In an exemplary embodiment, the AMF may send a session context request to a randomly selected SMF; if receiving a message which is returned by the randomly selected SMF and supports the iSMF, recording and updating an iSMF supporting capability parameter corresponding to the randomly selected SMF; and if a message which is returned by the randomly selected SMF and does not support the message as the iSMF is received, randomly selecting the SMF again, and sending a session context request to the newly selected SMF.

That is, the AMF may randomly select an SMF, and send a session context Request Nsmf _ pduse _ CreatSMContext _ Request to the randomly selected SMF, after the randomly selected SMF receives the Request, if the randomly selected SMF has the capability of supporting as an smsf, return a message supporting as an smsf to the AMF, and after receiving the message, the AMF records and updates an smsf capability parameter corresponding to the SMF locally stored by the AMF; and if the randomly selected SMF does not have the capability of supporting the iSMF, returning a message which does not support the iSMF to the AMF, and after receiving the message, the AMF reselects the SMF randomly and sends a session context request to the reselected SMF until the SMF which supports the iSMF capability is found.

In the embodiment of the present disclosure, whether the SMF has the smsf capability may be determined according to the smsf-supporting smsf capability parameter. If the parameter of the SMF for supporting the iSMF capability is yes, the SMF supports the iSMF capability; and if the parameter of the SMF for supporting the iSMF capability is not, the SMF does not support the iSMF capability.

In an exemplary embodiment, the AMF may select a roaming-place SMF that supports the immf capability parameter of yes as the immf.

In step S108, the home SMF is accessed through the insmf to establish a session connection.

In the embodiment of the disclosure, the AMF can access the home SMF through the insmf determined by the method, and since the insmf determined by the method has the capability of supporting as an insmf, the insmf determined by the method is safer to access the home SMF; the above-mentioned imsf-supporting capability parameters of the imsf may be manually configured, and thus may increase the flexibility of deployment.

In an exemplary embodiment, the AMF may send the DNN parameter and the first tracking area identity TAI to the home SMF, so that the home SMF obtains the intermediate user plane function network element UPF through the first tracking area identity TAI matching, and obtains the home UPF through the DNN parameter matching.

For example, the AMF may initiate a local TOPO discovery message by matching the cached Home province hSMF with the TAI and S-NSSAI; the appropriate SMF in roaming province is matched by DNN and S-NSSAI as an insmf.

hSMF can be matched to itupf by TAI and matched to anchor UPF (also called home UPF), i.e. hfpf, by DNN. And the signaling is successfully transferred to the exit gateway of the home province through the iSMF- > hSMF- > iUPF- > hUPF flow.

The following describes, with reference to fig. 2, a flow of interaction of the session processing system in the method provided in the embodiment of the present disclosure by way of example, but the scope of the present disclosure is not limited thereto.

In step S21, after the UE initiates a session creation request, the AMF selects a suitable SMF in the cache list for the session, replaces tai with predicted-tai when there is no suitable SMF, and initiates an NF discovery request to the LNRF: and the Nnrf _ NFdiscovery request (carrying preferred-tai/DNN/s-nssai/imsi).

In step S22, the LNRF transmits an nrf _ NFDiscovery request to the HNRF.

In step S23, HNRF obtains hSMF from DNN and S-nssai matching, and returns a nfrf _ NFDiscovery response (carrying (preferredetamatchind) result) to LNRF.

In step S24, the LNRF returns an nrf _ NFDiscovery response (carry) to the AMF.

In step S25, the AMF randomly selects an SMF.

In step S26, the AMF sends a session context Request Nsmf _ pdusesion _ CreatSMContext _ Request to the randomly selected SMF.

In step S27, if the SMF is not supported as an insmf, the request is rejected.

In step S28, the AMF buffers the information whether the SMF supports the insmf, and reselects the insmf.

In step S29, the AMF sends a session context Request Nsmf _ pdusesion _ CreatSMContext _ Request to the reselected SMF.

In step S210, the reselected SMF, which sends Nsmf _ postpdesses _ Request (carrying ismfurl) to hSMF, supports the imsf capability.

In step S211, the reselected SMF sends PFCP _ Session _ Establishment _ Request/Response to the ioupf.

In step S212, a session is established, policy charging and other procedures are established, and information such as the UE address and the tunnel ID is acquired.

Referring to fig. 3, in the embodiment of the present disclosure, a user initiates registration through a UE, and after the registration is successful, the UE may send a session establishment request to an AMF, and the AMF may receive the session establishment request.

The AMF may look up whether there is a conforming SMF based on the DNN parameter in the session establishment request. If there is no matching SMF, the AMF may replace tai with predicted-tai in the process of selecting a suitable SMF, and transfer the predicted-tai to the roaming province LNRF to obtain hSMF, and the AMF may cache information of the hSMF matched with the LNRF.

AMF can match and obtain hSMF from the cache list according to tai, DNN and S-NSSAI parameters.

AMF can randomly select SMF of a roaming place according to the parameters of tai, DNN and S-NSSAI, and judges whether the SMF opens the capability of the iSMF, if not, the SMF reselects; if yes, the SMF is taken as the iSMF, and the ismfurl is acquired.

The hSMF can match the iUPF through the tai and match the hUPF through the DNN, and the signaling is successfully transferred to the exit gateway of the home province through the iSMF- > hSMF- > iUPF- > hUPF stream.

The following is an embodiment of an access mobility management network element of the present disclosure, which may be used to execute an embodiment of the method of the present disclosure. For details not disclosed in the embodiments of the access mobility management element of the present disclosure, refer to the embodiments of the method of the present disclosure.

As shown in fig. 4, the access mobility management network element 400 may include: a request receiving module 402, an SMF determining module 404, an immf determining module 406, and a session establishing module 408.

The request receiving module 402 is configured to receive a session establishment request sent by a user equipment, where the session establishment request includes a data network name DNN parameter; the SMF determining module 404 is configured to determine a home session management network element SMF according to the session establishment request; the imsf determining module 406 is configured to use a roaming place SMF that supports the capability of the intermediate session management network element imsf as the imsf; the session establishing module 408 is configured to send the session establishment request to the home SMF through the immf, so as to establish a session connection.

In an exemplary embodiment, the immf determination module 406 includes: a request sending unit, configured to send a session context request to a randomly selected SMF; a recording and updating unit, configured to record and update an imsf-supported capability parameter corresponding to the randomly selected SMF if a message that supports the SMF returned by the randomly selected SMF is received; and a resending unit, configured to, if a message returned by the randomly selected SMF and not supporting the SMF is received, reselect the SMF randomly, and send the session context request to the reselected SMF.

In an exemplary embodiment, the immf determination module 406 includes: and the iSMF selection unit is used for selecting the roaming place SMF which supports the iSMF capability parameter as the iSMF.

In an exemplary embodiment, the SMF is configured with a parameter specifying whether the SMF supports the capability as an insmf.

In an exemplary embodiment, the session establishment request comprises a data network name DNN parameter, a first tracking area identification TAI, and a single network slice selection assistance information S-NSSAI parameter; the SMF determining module 404 includes: an identifier replacing unit configured to replace the first tracking area identifier TAI with a second tracking area identifier TAI; a home SMF determining unit, configured to send the DNN parameter, the second tracking area identity TAI, and the S-NSSAI parameter to a roaming-location network storage network element LNRF, so that the LNRF sends the DNN parameter, the second tracking area identity TAI, and the S-NSSAI parameter to a total network storage network element HNRF, and the HNRF determines the home SMF according to the DNN parameter and the S-NSSAI parameter, and returns the home SMF information to the LNRF; and the home SMF information receiving unit is used for receiving the home SMF information returned by the LNRF and storing the home SMF information into a cache list.

In an exemplary embodiment, the SMF determination module 404 further includes: and the home SMF matching unit is used for matching and obtaining the home SMF from the cache list according to the first tracking area identification TAI and the S-NSSAI parameter.

In an exemplary embodiment, the session establishment request comprises a data network name, DNN, parameter and a first tracking area identification, TAI;

the session establishing module 408 includes: and a session establishing unit, configured to send the DNN parameter and the first tracking area identity TAI to the home SMF, so that the home SMF obtains a middle user plane function network element UPF through the first tracking area identity TAI matching, and obtains a home UPF through the DNN parameter matching.

It is noted that the block diagrams shown in the above figures are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and/or processor terminal devices and/or microcontroller terminal devices.

Fig. 5 is a schematic structural diagram of an electronic device according to an exemplary embodiment. It should be noted that the electronic device shown in fig. 5 is only an example, and should not bring any limitation to the functions and the scope of use of the embodiments of the present disclosure.

As shown in fig. 5, the electronic apparatus 500 includes a Central Processing Unit (CPU)501 that can perform various appropriate actions and processes in accordance with a program stored in a Read Only Memory (ROM)502 or a program loaded from a storage section 508 into a Random Access Memory (RAM) 503. In the RAM503, various programs and data necessary for the operation of the system 500 are also stored. The CPU 501, ROM502, and RAM503 are connected to each other via a bus 504. An input/output (I/O) interface 505 is also connected to bus 504.

The following components are connected to the I/O interface 505: an input portion 506 including a keyboard, a mouse, and the like; an output portion 507 including a display such as a Cathode Ray Tube (CRT), a Liquid Crystal Display (LCD), and the like, and a speaker; a storage portion 508 including a hard disk and the like; and a communication section 509 including a network interface card such as a LAN card, a modem, or the like. The communication section 509 performs communication processing via a network such as the internet. The driver 510 is also connected to the I/O interface 505 as necessary. A removable medium 511 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like is mounted on the drive 510 as necessary, so that a computer program read out therefrom is mounted into the storage section 508 as necessary.

In particular, according to an embodiment of the present disclosure, the processes described above with reference to the flowcharts may be implemented as computer software programs. For example, embodiments of the present disclosure include a computer program product comprising a computer program embodied on a computer readable medium, the computer program comprising program code for performing the method illustrated in the flow chart. In such an embodiment, the computer program may be downloaded and installed from a network through the communication section 509, and/or installed from the removable medium 511. The above-described functions defined in the system of the present disclosure are executed when the computer program is executed by the Central Processing Unit (CPU) 501.

It should be noted that the computer readable media shown in the present disclosure may be computer readable signal media or computer readable storage media or any combination of the two. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, terminal device, or apparatus, or any combination of the foregoing. More specific examples of the computer readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the present disclosure, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, terminal device, or apparatus. In contrast, in the present disclosure, a computer-readable signal medium may include a propagated data signal with computer-readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take many forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, terminal device, or apparatus. Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, fiber optic cable, RF, etc., or any suitable combination of the foregoing.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams or flowchart illustration, and combinations of blocks in the block diagrams or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

The units described in the embodiments of the present disclosure may be implemented by software or hardware. The described units may also be provided in a processor, and may be described as: a processor includes a transmitting unit, an obtaining unit, a determining unit, and a first processing unit. The names of these units do not in some cases constitute a limitation to the unit itself, and for example, the sending unit may also be described as a "unit sending a picture acquisition request to a connected server".

As another aspect, the present disclosure also provides a computer-readable medium, which may be contained in the apparatus described in the above embodiments; or may be separate and not incorporated into the device. The computer readable medium carries one or more programs which, when executed by a device, cause the device to comprise: receiving a session establishment request sent by user equipment, wherein the session establishment request comprises a Data Network Name (DNN) parameter; determining a home location session management network element SMF according to the session establishment request; taking SMF of a roaming place supporting the capability of an intermediate session management network element iSMF as the iSMF; and sending the session establishment request to the home SMF through the iSMF so as to establish session connection.

Exemplary embodiments of the present disclosure are specifically illustrated and described above. It is to be understood that the disclosure is not limited to the precise arrangements, instrumentalities, or instrumentalities described herein; on the contrary, the disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A session handling method, characterized in that the method is performed by an access mobility management element, AMF, and the method comprises:

receiving a session establishment request sent by user equipment;

determining a home location session management network element SMF according to the session establishment request;

taking SMF of a roaming place supporting the capability of an intermediate session management network element iSMF as the iSMF;

accessing the home SMF through the iSMF to establish a session connection.

2. The method of claim 1, wherein using as the immf a roaming-place SMF that supports an immf capability, comprises:

sending a session context request to the randomly selected SMF;

if receiving a message which is returned by the randomly selected SMF and supports the iSMF as the iSMF, recording and updating an iSMF supporting capability parameter corresponding to the randomly selected SMF;

and if receiving a message which is returned by the randomly selected SMF and does not support the message as the iSMF, randomly selecting the SMF again, and sending the session context request to the newly selected SMF.

3. The method of claim 1 or 2, wherein using the roaming-place SMF that supports the capability of the intermediate session management network element immf as the immf comprises:

the roaming-place SMF that supports the immf capability parameter yes is selected as the immf.

4. The method of claim 2, wherein the SMF is configured with a parameter thereon specifying whether the SMF supports the capability as an insmf.

5. The method of claim 1, wherein the session establishment request comprises a Data Network Name (DNN) parameter, a first Tracking Area Identification (TAI) and a single network slice selection assistance information (S-NSSAI) parameter;

wherein, determining a home session management network element SMF according to the session establishment request includes:

replacing the first tracking area identity TAI with a second tracking area identity TAI;

sending the DNN parameter, the second tracking area identification TAI and the S-NSSAI parameter to a roaming location network storage network element (LNRF) so that the LNRF sends the DNN parameter, the second tracking area identification TAI and the S-NSSAI parameter to a total network storage network element (HNRF), the HNRF determines the home SMF according to the DNN parameter and the S-NSSAI parameter, and returns the home SMF information to the LNRF;

and receiving the home SMF information returned by the LNRF, and storing the home SMF information into a cache list.

6. The method of claim 5, wherein determining a home session management network element (SMF) based on the session establishment request further comprises:

and matching and obtaining the home SMF from the cache list according to the first tracking area identification TAI and the S-NSSAI parameter.

7. The method of claim 1, wherein the session establishment request comprises a Data Network Name (DNN) parameter and a first Tracking Area Identification (TAI);

wherein accessing the home SMF through the iSMF to establish a session connection comprises:

and sending the DNN parameter and the first tracking area identification TAI to the home SMF, so that the home SMF obtains a middle user plane function network element UPF through the first tracking area identification TAI matching, and obtains a home UPF through the DNN parameter matching.

8. An access mobility management network element, comprising:

the request receiving module is used for receiving a session establishment request sent by user equipment;

an SMF determining module, configured to determine a home session management network element SMF according to the session establishment request;

the system comprises an iSMF determining module, a network element management module and a network element management module, wherein the iSMF determining module is used for taking a roaming place SMF supporting the capability of an intermediate session management network element iSMF as the iSMF;

and the session establishing module is used for sending the session establishing request to the home SMF through the iSMF so as to establish session connection.

9. An electronic device, comprising:

at least one processor;

storage means for storing at least one program which, when executed by the at least one processor, causes the at least one processor to carry out the method of any one of claims 1 to 7.

10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the method according to any one of claims 1 to 7.