CN106686553B

CN106686553B - Method and device for carrying out multicast on core network EPC

Info

Publication number: CN106686553B
Application number: CN201510762892.3A
Authority: CN
Inventors: 董明霞; 王欣
Original assignee: Datang Mobile Communications Equipment Co Ltd
Current assignee: Datang Mobile Communications Equipment Co Ltd
Priority date: 2015-11-10
Filing date: 2015-11-10
Publication date: 2020-07-17
Anticipated expiration: 2035-11-10
Also published as: CN106686553A

Abstract

The invention provides a method for carrying out multicast on a core network EPC and a device for carrying out multicast on the core network EPC, wherein the EPC is provided with a mapping relation between an IP address of a multicast group and an IP address of a train access unit TAU, wherein the IP address of the multicast group is associated with a display terminal, and the IP address of the TAU is associated with the TAU; the method comprises the following steps: the EPC receives a data message sent by a PIS server; the data message carries the IP addresses of one or more multicast groups; searching the IP address of the TAU corresponding to the IP address of the one or more multicast groups; sending the data message to one or more TAUs associated with the IP addresses of the one or more TAUs; and the one or more TAUs are used for respectively forwarding the data messages to the display terminals associated with the IP addresses of the multicast group. The method and the device realize that the PIS server can directly access a plurality of display terminals hung under the TAU through the EPC at the same time.

Description

Method and device for carrying out multicast on core network EPC

Technical Field

The present application relates to the field of wireless communication technologies, and in particular, to a method and an apparatus for performing multicast on an EPC (core network).

Background

With the development of the times and the progress of science and technology, more and more information media and ways are obtained by people, in the past, people almost obtain information through paper media, such as buying books or going to libraries, and at present, people can obtain various information at any time and any place through multimedia ways, such as display terminals on buses and subways, and the method is very convenient.

Taking a PIS (Passenger Information System) as an example, the PIS is a service System for providing various Information to passengers. The PIS relies on a multimedia network technology, takes a computer system as a core, and takes a station and a vehicle-mounted display terminal as media to provide information services for passengers. Referring to fig. 1, a schematic diagram of a communication structure of a PIS multicast in the prior art is shown, in a subway, a typical PIS application scenario is as follows: the PIS server 11 issues a plurality of data streams to a plurality of display terminals 14 hung under a plurality of TAU (train access Unit) 13 through an sgi (server Gateway interface) side (not shown in the figure) of an EPC (Evolved Packet Core) 12. As shown in fig. 1, the EPC receives messages of three data flows, 1, 2, and 3, sent by the PIS server, and then sends the message of the 1 st data flow to a first TAU (left one in the figure), sends the message of the 2 nd data flow to a second TAU (center in the figure), sends the message of the 3 rd data flow to a third TAU (right one in the figure), and finally sends the received messages of the data flows to respective display terminals hung down by the three TAUs.

Further, referring to the schematic diagram of the communication process of the PIS multicast in the prior art shown in fig. 2, in the prior art, the destination address of the packet of the data stream sent by the PIS server to the EPC is the multicast IP address of the TAU downlink display terminal, this address is a fixed IP agreed by the protocol, the number segment is 224.0.0.0 to 239.255.255.255, and it is not the IP address assigned to the TAU by the core network EPC, but according to the agreement, the EPC can only send the packet of one data stream to one corresponding TAU by internal five-tuple matching (including the IP address of the TAU), and how many corresponding data streams need to be sent by the PIS server side depending on the agreement.

Therefore, the prior art mainly has the following problems:

firstly, the EPC can only process the message of which the destination address is the IP address of the TAU, namely the PIS server cannot directly access the display terminal hung below the TAU through the EPC;

secondly, the EPC can only process data flows one-to-one, that is, one-to-many message transmission between the PIS server and a plurality of display terminals hung under the TAU cannot be realized.

Disclosure of Invention

In view of the above problems, embodiments of the present application are proposed to provide a method for multicasting on a core network EPC and a corresponding apparatus for multicasting on a core network EPC, which overcome or at least partially solve the above problems.

In order to solve the above problem, an embodiment of the present application discloses a method for performing multicast on an EPC (core network), where the EPC is configured with a mapping relationship between an IP address of a multicast group and an IP address of a train access unit TAU, where the IP address of the multicast group is associated with a display terminal, and the IP address of the TAU is associated with the TAU;

the method comprises the following steps:

the EPC receives a data message sent by a PIS server; the data message carries the IP addresses of one or more multicast groups;

searching the IP addresses of one or more TAUs corresponding to the IP addresses of the one or more multicast groups;

sending the data message to one or more TAUs associated with the IP addresses of the one or more TAUs; and the one or more TAUs are used for respectively forwarding the data messages to the display terminals associated with the IP addresses of the multicast group.

In a preferred embodiment of the present invention, the mapping relationship between the IP address of the multicast group and the IP address of the train access unit TAU is configured in a newly added multicast address mapping table on the PGW network element side of a packet data node gateway in the EPC.

In a preferred embodiment of the present invention, the mapping relationship between the multicast group IP address and the IP address of the train access unit TAU is configured in an original routing table in the EPC.

In a preferred embodiment of the present invention, the step of sending the data packet to one or more TAUs associated with the IP addresses of the one or more TAUs includes:

performing downlink service flow template D L-TFT information matching on the IP addresses of the one or more TAUs, and searching first tunnel information corresponding to the IP addresses of the one or more TAUs;

and sending the data message to the one or more TAUs according to the tunnel information.

In a preferred embodiment of the present invention, when the IP address of the TAU corresponding to the IP address of the one or more multicast groups in the routing relation table fails to be searched, the method further includes:

d L-TFT information matching is carried out on the IP addresses of the one or more multicast groups, and second tunnel information corresponding to the IP addresses of the one or more multicast groups is searched;

and sending the data message to the one or more display terminals associated with the IP address of the multicast group according to the tunnel information.

Correspondingly, the embodiment of the application also discloses a device for multicast on the core network EPC, wherein the EPC is configured with a mapping relation between the IP address of the multicast group and the IP address of the train access unit TAU, the IP address of the multicast group is associated with the display terminal, and the IP address of the TAU is associated with the TAU;

the device comprises:

the receiving module is used for receiving the data message sent by the PIS server; the data message carries the IP addresses of one or more multicast groups;

the searching module is used for searching the IP address of the TAU corresponding to the IP address of the one or more multicast groups;

a sending module, configured to send the data packet to one or more TAUs associated with the IP addresses of the one or more TAUs; and the one or more TAUs are used for respectively forwarding the data messages to the display terminals associated with the IP addresses of the multicast group.

In a preferred embodiment of the present invention, the sending module includes:

the first tunnel information matching module is used for performing downlink service flow template D L-TFT information matching on the IP addresses of the one or more TAUs and searching first tunnel information corresponding to the IP addresses of the one or more TAUs;

and the first sending module is used for sending the data message to the one or more TAUs according to the tunnel information.

In a preferred embodiment of the present invention, when the IP address of the TAU corresponding to the IP address of the one or more multicast groups in the routing relation table fails to be searched, the apparatus further includes:

the second tunnel information matching module is used for performing D L-TFT information matching on the IP addresses of the one or more multicast groups and searching for second tunnel information corresponding to the IP addresses of the one or more multicast groups;

and the second sending module is used for sending the data message to the one or more display terminals associated with the IP address of the multicast group according to the tunnel information.

The embodiment of the invention has the following advantages:

the embodiment of the invention discloses a method for multicast on an EPC (evolved packet core), which is characterized in that a PIS (peer-to-peer server) issues a data message with a destination address being the IP address of a multicast group by configuring the mapping relation between the IP address of the multicast group and the IP address of a TAU (train access unit) in the EPC, after the data message reaches the EPC, the EPC searches the corresponding IP address of the TAU through the mapping relation between the IP address of the multicast group and the IP address of the TAU, and then simultaneously issues the data message to a plurality of TAUs, wherein the TAUs are used for respectively forwarding the data message to a display terminal associated with the IP address of the multicast group. Compared with the prior art, although the destination address of the data message in the application is not the IP address allocated to the TAU by the EPC when the terminal bearer is established, the data message can still be continuously transmitted through the mapping relation between the IP address of the multicast group and the IP address of the TAU without being discarded. Therefore, no matter the data message sent by the PIS server to the EPC contains a plurality of IP addresses of the multicast groups associated with the display terminals, the IP address of the TAU corresponding to the IP address of the multicast group can be found through the mapping relation, the PIS server can directly access the plurality of display terminals hung below the TAU through the EPC, and the practical application scene of multicast based on the EPC in the industry application field is solved.

Furthermore, the embodiment of the invention can configure the mapping relation between the IP address of the multicast group and the IP address of the TAU in the original routing table in the EPC, thereby not needing to develop a new data table in the EPC, reducing the system overhead of the EPC and achieving the purpose of system optimization; meanwhile, by utilizing a high-efficiency route searching mechanism, the EPC can quickly find the IP address of the TAU corresponding to the IP address of the multicast group, and the system performance and efficiency are improved. And the multicast address matching by using the routing table only relates to the modification of PGW network element service processing codes, and has small modification amount and short development period.

Drawings

Fig. 1 is a schematic diagram of a communication structure of a PIS multicast in the prior art;

fig. 2 is a schematic diagram of a communication process of a PIS multicast in the prior art;

fig. 3 is a flowchart of steps of embodiment 1 of a method for performing multicast on an EPC (core network) according to the present application;

fig. 4 is a schematic diagram of a communication structure for multicast on an EPC (core network) according to the present application;

fig. 5 is a flowchart of steps of embodiment 2 of a method for performing multicast on an EPC (core network) according to the present application;

fig. 6 is a block diagram of an embodiment of an apparatus for performing multicast on an EPC (core network) according to the present application.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, the present application is described in further detail with reference to the accompanying drawings and the detailed description.

One of the core concepts of the embodiments of the present application is to provide a multicast address mapping method based on a route lookup mechanism, and configure a mapping relationship between an IP address of a multicast group and an IP address of a TAU in an EPC, so that the EPC can quickly lock the IP address of the TAU corresponding to the IP address of the multicast group and forward a packet.

Referring to fig. 3, a flowchart of steps of embodiment 1 of a method for performing multicast on an EPC (core network) of the present application is shown, where in this embodiment of the method, a mapping relationship between an IP address of a multicast group and an IP address of a TAU may be configured in the EPC, where the IP address of the multicast group may be associated with a display terminal, and the IP address of the TAU may be associated with the TAU, where this embodiment may specifically include the following steps:

step 101, receiving a data message sent by a PIS (passenger information system) server by the EPC;

wherein the data packet carries the IP addresses of one or more multicast groups.

A datagram is a basic unit of data transmitted through a network and contains a header (header) and the data itself, where the header describes the destination of the data and the relationship with other data. A data message is a complete, independent data entity that carries information to be transferred from a source computer to a destination computer independent of previous exchanges between the source and destination computers and the transport network.

In the data packet mode of operation, each data packet carries sufficient information on its own that its transmission is handled separately. In the whole data message transmission process, a virtual circuit does not need to be established, the network node performs routing selection for each data message, and each data message cannot reach a destination node in sequence and some data messages may be lost.

The TCP/IP protocol defines a packet, called an IP Datagram (IP Datagram), for transmission over the internet. This is a hardware independent virtual packet, consisting of two parts, header and data. The first part of the header is a fixed length, 20 bytes in total, that all IP datagrams must have. Following the fixed part of the header are some optional fields, the length of which is variable. The source and destination addresses in the header are both IP protocol addresses.

The fields in the fixed part of the IP datagram header include:

(1) version: accounting for 4 bits, refers to the version of the IP protocol. The IP protocol versions used by both parties must be consistent. The widely used IP protocol version number is 4 (i.e., IPv 4).

(2) Header length: with 4 bits, the maximum representable decimal value is 15. Note that the unit of the number represented by this field is a 32-bit word (1 32-bit word length is 4 bytes), so when the header length of the IP is 1111 (i.e., 15 decimal), the header length reaches 60 bytes. When the header length of the IP packet is not an integer multiple of 4 bytes, it must be padded with the last padding field. The data portion therefore starts permanently at an integer multiple of 4 bytes, which is convenient when implementing the IP protocol. The limitation of the header length to 60 bytes has the disadvantage that it may sometimes not be sufficient. But it is desirable to minimize the overhead for the user. The most common header length is 20 bytes (i.e., a header length of 0101), and no option is used.

(3) Differentiated services: occupying 8 bits for better service. This field is called service type in the old standard, but has not been used in practice. In 1998 the IETF renames this field to differentiated services ds (differentiated services). This field is only active when differentiated services are used.

(4) Total length: the total length refers to the length of the sum of the header and data, in bytes. The total length field is 16 bits, so the maximum length of the datagram is 216-1-65535 bytes.

Each data link layer below the IP layer has its own frame format including the maximum length of the data field in the frame format, which is called the maximum transfer unit mtu (maximum transfer unit). When a datagram is encapsulated into a link layer frame, the total length of the datagram (i.e., the header plus the data portion) must not exceed the MTU value of the underlying data link layer.

(5) Identification (identification): occupying 16 bits. The IP software maintains a counter in memory that increments by 1 each time a datagram is generated, and assigns this value to the identification field. But this "identity" is not a sequence number because IP is a connectionless service and there is no problem with the in-sequence reception of datagrams. When a datagram must be fragmented due to the length exceeding the MTU of the network, the value of this identification field is copied into the identification fields of all datagrams. The same identification field value enables each fragmented datagram piece to be finally and correctly reassembled into the original datagram.

(6) Flag (flag): it takes 3 bits, but only 2 bits make sense.

Wherein, the lowest bit in the flag field is denoted as mf (morefragment). MF 1 means datagram that "there is fragment" later. MF ═ 0 indicates that this is the last of several datagrams.

One bit in the middle of the flags field is denoted as DF (Don't Fragment), meaning "cannot Fragment". Fragmentation is only allowed when DF is 0.

(7) Sheet offset: occupying 13 bits. The slice offset indicates: after the longer packet is fragmented, the relative position of a fragment in the original packet. That is, where the slice starts relative to the start of the user data field. The slice offset is in offset units of 8 bytes. That is, the length of each slice must be an integer multiple of 8 bytes (64 bits).

(8) Time-to-live, 8-bit, the common english abbreviation for the time-to-live field is TT L (TimeTo L ive), indicating the lifetime of a datagram in the network the field is set by the source from which the datagram originates.

(9) Protocol: the protocol field, which takes 8 bits, indicates which protocol the data carried in this datagram is using in order to let the IP layer of the destination host know which process the data part should be handed over to.

(10) Header checksum: occupying 16 bits. This field only checks the header of the datagram but does not include the data portion. This is because each time a datagram passes through a router, the router recalculates a header checksum (some fields, such as time-to-live, flags, slice offsets, etc., may change). Not checking the data portion may reduce computational effort.

(11) Source address: accounting for 32 bits.

(12) Destination address: accounting for 32 bits.

In practical application, the PIS server provides real-time dynamic multimedia information such as riding instructions, service time, train arrival time, train schedule, administrator bulletin, government bulletin, travel reference, stock information, media news, live events, advertisements and the like under normal conditions. And providing dynamic emergency evacuation prompt under abnormal conditions of fire, blockage, terrorist attack and the like. The PIS provides an audio broadcast platform, a video program playing platform, an emergency situation warning, warning platform and an emergency call platform for passengers and a central control room. A video surveillance, storage and intervention system is also provided for the central control room.

The PIS can be summarized into the following four parts according to the classification of the system:

a broadcast communication system, comprising:

1. a driver control panel;

2. a driver intercom unit;

3. a broadcast system control device;

4. a digital voice broadcasting unit;

5. a microphone;

6. an interface connection device of a vehicle;

7. a passenger emergency alert device;

8. an on-board speaker system.

Secondly, passenger information display system and multimedia playing system include:

1. l ED endpoint display;

2. l ED passenger display;

3. l ED vehicle body outside display;

4. l CD information display;

5. a dynamic electronic map;

6. a multimedia server;

7. a multimedia controller;

8. a vehicle network interface.

Thirdly, video monitoring, comprising:

1. a video monitoring server;

2. a video surveillance display;

3. a video surveillance vehicle interface;

4. and a monitoring camera.

Fourthly, the emergency guarantee system includes:

1. an emergency call unit;

2. and an alarm unit.

In addition, the embodiment of the present invention is based on L TE (L ong terminal Evolution, long Term Evolution) wireless communication technology, 4G is an unparalleled advantage as a fourth generation mobile communication technology, which can transmit voice, text, video and image information quickly, and can meet the requirements of almost all users for wireless services, the standard of the international telecommunication union for 4G System is a System that conforms to 100Mbit/s data transmission speed, when there is no genuine high-speed session between machines, L TE mainly studies the long Term Evolution technology of 3GPP radio access network, the upgraded L TE Advanced will eventually meet the requirements of the international telecommunication union for 4G System, SAE (System Architecture Evolution) is a long Term Evolution study of core network, which defines an all-IP Packet core network EPC, the System is characterized by only having Packet domains without circuit domain, based on all-IP Architecture, separated control and bearer, and flat network structure, wherein the System includes Mobility Management Entity (MME), Policy, Charging Gateway, and Charging Policy, wherein the System includes SGW and mobility management (SGW) and mobility management Policy, wherein SGW Gateway, and mobility management Policy, wherein SGW, and mobility management Policy are often referred to SGW.

The main components of the EPC are:

MME: managing session (session) status and authenticating and tracking users on the network;

SGW: routing data through an access network; the user plane function of the SGSN network element in the original 3G network is sometimes written as S-GW;

the PGW is used as a port between L TE network and other packet data networks, manages the quality of service (QoS) and provides deep Data Packet Inspection (DPI), the function of GGSN network element in the original 3G network is sometimes written as P-GW;

PCRF: and the service data flow detection, policy enforcement and flow charging mode are supported.

In summary, the EPC has the following characteristics:

1. the core network is converged, and the switching function is routed;

2. the service plane is completely separated from the control plane;

3. the number of network elements is minimized, and the protocol level is optimized;

4. flattening the network and carrying out full IP.

In the embodiment of the present invention, the EPC may receive a data packet sent by the PIS server, where the data packet carries IP addresses of one or more multicast groups, that is, a destination address of the data packet is an IP address of the multicast group, and the IP address of the multicast group is associated with the display terminal. For example, the IP addresses of three display terminals in the multicast group are 1.1.1.1, 2.2.2.2, and 3.3.3.3, respectively, then the data packet sent by the PIS server will include the three IP addresses, and the three IP addresses are all the destination addresses of the data packet. Of course, it is also possible that the EPC actively acquires the data packet of the PIS server, and a data transmission mode between the EPC and the PIS server may be selected according to actual requirements, which is not limited in the embodiment of the present invention.

Step 102, searching for the IP addresses of one or more TAUs corresponding to the IP addresses of one or more multicast groups;

after the data message reaches the EPC, the EPC needs to continue to send the data message to one or more TAU, but a destination address of the data message is an IP address of one or more multicast groups associated with the display terminal, and therefore, the EPC needs to search for the IP addresses of one or more TAU corresponding to the IP addresses of the one or more multicast groups through a mapping relationship between the IP addresses of the multicast groups and the IP addresses of the TAU.

In a preferred embodiment of the present invention, the mapping relationship between the IP address of the multicast group and the IP address of the TAU is configured in a newly added multicast address mapping table on the PGW network element side of a packet data node gateway in the EPC.

PGWs are important network elements in the mobile communications network EPC. The EPC network is actually an evolved version of the PS domain of the original 3G core network, and the PGW is also equivalent to an evolved GGSN (Gateway GPRS Support Node) network element, and its function and role are equivalent to those of the original GGSN network element. The PGW Network element entity introduced in the EPC system is called a PDN (Public Data Network) Gateway in english, and it is similar to the function of a GGSN Network element, and provides functions of session management and bearer control, Data forwarding, IP address allocation, non-3 GPP user access, and the like for a border Gateway of the EPC Network. It is the anchor point for 3GPP access and non-3 GPP access to the public data network PDN. The 3GPP access refers to a wireless access technology coming out of a 3GPP standard family, for example, a mobile phone in china mobile and china unicom is a 3GPP access technology in China at present; the non-3 GPP access is a radio access technology outside the 3GPP standard family, typically a CDMA access technology such as chinese telecommunications, and a WiFi access technology which is popular at present. That is, in the EPC network, if the mobile terminal is a non-3 GPP access, it may not pass through the MME network element and the SGW network element, but must pass through the PGW network element, and then can access the PDN.

The main functions of the PGW network element include:

the method comprises the steps of I, session and Bearer management, wherein a concept of Default Bearer does not exist in a 2G/3G network, after the concept is attached to the network, a PDP (Packet Data Protocol) context does not need to be activated and an IP address does not need to be allocated under the condition that no service request exists, a Default Bearer (Default Bearer) is established and the IP address is allocated to a terminal when a user is attached to an L TE network, so that the functional characteristic of 'permanent online' is provided for the user, the time delay caused by connection reestablishment when the user receives and sends Data is reduced, and after the Default Bearer is established, a special Bearer can be established under the condition that high QoS service exists.

For example, when an EPC network user accesses a Web page, because the service request does not have a high requirement for delay of a data message, the service request may perform data message transmission and reception on a default bearer; if the user initiates a voice call, the default bearer cannot guarantee the requirements of transmission delay, packet loss rate and the like, at this time, the PCRF network element needs to judge and trigger, the PGW is required to create a special bearer for the user, and a voice data packet is transmitted on the bearer, so as to improve the quality of the voice call and guarantee good user experience. In addition, after the voice call is finished, the proprietary bearer is deleted, and the default bearer is kept during the user networking.

2. IP address allocation: the PGW is responsible for allocating IP addresses for the accessed users, and then the transmission of the data messages is carried out under the IP addresses, and the address types allocated by the PGW comprise IP V4, IP V6 or IPV4+ IPV 6.

An IPV4 address space has certain limitations, but IPV6 is a direction of development of subsequent internet networks due to rich address resources and greatly improved security, and one bearer can be regarded as a data packet transmission channel to which an IP address is allocated, if an IPV4 address type is allocated, a terminal can only perform information interaction with a computer or server in an external data network whose address type is also IPV4, and IPV6 is also the same, and if a bearer type supports IPV4V6, which is also called Dual Stack (Dual Stack), addresses of IPV4 and IPV6 can be simultaneously connected to one bearer, thereby undoubtedly saving bearer resources of a network.

In the embodiment of the present invention, the mapping relationship between the IP address of the multicast group and the IP address of the TAU may be the mapping between the IP address of the multicast group and the IP address of the TAU. For example, the IP address of TAU 1 is 4.4.4.4, two display terminals are hung, the IP addresses of the two display terminals are 1.1.1.1 and 2.2.2, respectively, the IP address of TAU2 is 5.5.5.5, one display terminal is hung, and the IP address of the display terminal is 3.3.3.3.3, then, in the multicast address mapping table, 1.1.1.1 and 2.2.2.2 are mapped with 4.4.4.4, and 3.3.3.3 is mapped with 5.5.5.5. Therefore, the EPC can find the IP address of the TAU corresponding to the destination address in the data packet through the multicast address mapping table, for example, the destination address of the data packet is 1.1.1.1, and can know that the IP address of the TAU corresponding to the IP address of the multicast group is 1.1.1.1 is 4.4.4.4 by looking up the multicast address mapping table. Of course, the mapping relationship may also be a mapping between a MAC address of a multicast group and an IP address of a TAU, or a mapping between an IP address of a multicast group and a MAC address of a TAU, and the specific mapping relationship may be selected according to actual applications, which is not limited in this embodiment of the present invention.

In the embodiment of the present invention, the newly added multicast address mapping table may be stored in a memory on the PGW network element side in the EPC, the multicast address mapping table may be configured as a sequence table, a linked list, or other types of tables, and the type of the mapping table may be selected according to actual requirements.

103, sending the data message to one or more TAUs associated with the IP addresses of the one or more TAUs;

when the EPC finds the IP addresses of one or more TAUs corresponding to the IP addresses of one or more multicast groups through the mapping relationship between the IP addresses of the multicast groups and the IP addresses of the TAUs, the EPC may send the data packet to the one or more TAUs associated with the IP addresses of the one or more TAUs.

In a preferred embodiment of the present invention, the step 103 may specifically include the following sub-steps:

substep 1031, performing downlink service flow template D L-TFT information matching on the IP addresses of the one or more TAUs, and searching for first tunnel information corresponding to the IP addresses of the one or more TAUs;

sub-step 1032, sending said data packet to said one or more TAUs according to said tunnel information.

And the one or more TAUs are used for forwarding the data messages to display terminals associated with the IP addresses of the multicast group respectively.

For example, after the EPC searches for the IP addresses of one or more TAUs corresponding to the IP address of the multicast group in the data packet through the mapping relationship between the IP address of the multicast group and the IP address of the TAU, D L-TFT information matching is performed according to the found IP address of the one or more TAUs, first tunnel information of a tunnel in which the EPC performs data interaction with each TAU is searched, after all the first tunnel information is obtained, the EPC transmits a data packet to each TAU through each tunnel corresponding to each first tunnel information, for example, the EPC performs D L-TFT information matching according to the IP address of TAU 1, knows that the EPC performs data interaction with the EPC TAU 1 through tunnel a, performs D L-TFT information matching according to the IP address of TAU2, knows that the EPC performs data interaction with TAU2 through tunnel B, and therefore, the EPC transmits a data packet to TAU 1 through tunnel a, and transmits the data packet to TAU2 through tunnel B, and then forwards the data packet to one or more terminals on which multiple links.

Of course, the above processing manner is only an example, and when the embodiment of the present invention is implemented, other processing manners may be set according to actual situations, for example, the EPC may directly send the data packet to one or more TAUs associated with the IP addresses of one or more TAUs according to the found IP addresses of the one or more TAUs; other processing methods may be used to enable the EPC to send the data packet to one or more TAU, which is not limited in the present invention.

The embodiment of the invention discloses a method for multicast on an EPC (evolved packet core), which is characterized in that a PIS (peer-to-peer server) issues a data message with a destination address being the IP address of a multicast group by configuring the mapping relation between the IP address of the multicast group and the IP address of a TAU (train access unit) in the EPC, after the data message reaches the EPC, the EPC searches the corresponding IP address of the TAU through the mapping relation between the IP address of the multicast group and the IP address of the TAU, and then simultaneously issues the data message to a plurality of TAUs, wherein the TAUs are used for respectively forwarding the data message to a display terminal associated with the IP address of the multicast group. Compared with the prior art, although the destination address of the data message in the application is not the IP address allocated to the TAU by the EPC when the terminal bearer is established, the data message can still be continuously transmitted through the mapping relation between the IP address of the multicast group and the IP address of the TAU without being discarded. Therefore, no matter the data message sent by the PIS server to the EPC includes a plurality of IP addresses of the multicast group associated with the display terminal, the IP address of the TAU corresponding to the IP address of the multicast group can be found through the mapping relationship. As shown in fig. 4, the method and the system realize that the PIS server can directly access a plurality of display terminals hung under the TAU through the EPC, and solve the practical application scenario of multicast based on the EPC in the industrial application field.

Referring to fig. 5, a flowchart of steps of embodiment 2 of a method for performing multicast on an EPC (core network) according to the present application is shown, in this embodiment, a mapping relationship between an IP address of a multicast group and an IP address of a TAU is configured in the EPC, where the IP address of the multicast group is associated with a display terminal, and the IP address of the TAU is associated with the TAU, where this embodiment may specifically include the following steps:

step 201, the EPC receives a data message sent by a passenger information system PIS server;

wherein, the data message carries the IP addresses of one or more multicast groups;

step 202, searching for the IP addresses of one or more TAUs corresponding to the IP addresses of the one or more multicast groups;

In a preferred embodiment of the present invention, the mapping relationship between the IP address of the multicast group and the IP address of the TAU is configured in an original routing table in the EPC.

In the embodiment of the present invention, the IP address of the multicast group and the IP address of the TAU may be configured in the original EPC routing table, where the IP address of the multicast group is a destination address of the data packet, and the IP address of the TAU is a next hop IP address of the destination address. Specifically, when the data packet reaches the PGW network element, the EPC performs route lookup according to the mapping relationship between the multicast group IP address and the TAU IP address in the configured routing table, and acquires the corresponding one or more TAU IP addresses through the IP addresses of one or more multicast groups.

In the embodiment of the present invention, the routing table may be configured as a static routing table or a dynamic routing table, or may be configured in other manners. It can be understood that the manner in which the mapping relationship between the IP address of the multicast group and the IP address of the TAU is configured in the routing table is applicable to the embodiment of the present application, and the embodiment of the present application does not limit this.

Step 203, when the IP address of the TAU corresponding to the IP address of the one or more multicast groups in the routing relation table fails to be searched, further comprising the following substeps:

substep 2031, performing D L-TFT information matching according to the IP addresses of the one or more multicast groups, and searching for second tunnel information corresponding to the IP addresses of the one or more multicast groups;

substep 2032, sending said data message to said one or more display terminals associated with the IP address of said multicast group using said tunnel information.

In practical application, when the EPC performs route lookup according to a mapping relationship between IP addresses of multicast groups and IP addresses of TAU in a configured routing table, there may be a case where the IP addresses of the corresponding TAU or TAU are not obtained through the IP addresses of one or more multicast groups, for example, the IP addresses of the multicast groups or the IP addresses of the TAU are configured incorrectly due to human errors, and the like.

Of course, the above processing manner is only an example, and when the embodiment of the present invention is implemented, other processing manners may be set according to actual situations, for example, the EPC may directly send the data packet to the display terminal associated with the IP address of one or more multicast groups according to the destination address in the data packet; other processing manners may also be adopted, so that the EPC may directly send the data packet to the display terminal associated with the IP address of one or more multicast groups, which is not limited in the present invention.

The difference between embodiment 2 of the method and embodiment 1 of the method is that the mapping relationship between the IP address of the multicast group and the IP address of the TAU is stored in the original EPC routing table; when the IP address of the TAU corresponding to the IP address of the one or more multicast groups in the routing relation table fails to be searched, the EPC may directly access the display terminal associated with the IP address of the multicast group according to the IP address of the multicast group in the data packet.

The embodiment of the invention can configure the mapping relation between the IP address of the multicast group and the IP address of the TAU in the original routing table in the EPC, thereby not needing to develop a new data table in the EPC, reducing the system overhead of the EPC and achieving the aim of system optimization; meanwhile, by utilizing a high-efficiency route searching mechanism, the EPC can quickly find the IP address of the TAU corresponding to the IP address of the multicast group, and the system performance and efficiency are improved. And the multicast address matching by using the routing table only relates to the modification of PGW network element service processing codes, and has small modification amount and short development period.

It should be noted that, for simplicity of description, the method embodiments are described as a series of acts or combination of acts, but those skilled in the art will recognize that the embodiments are not limited by the order of acts described, as some steps may occur in other orders or concurrently depending on the embodiments. Further, those skilled in the art will also appreciate that the embodiments described in the specification are presently preferred and that no particular act is required of the embodiments of the application.

Referring to fig. 6, a block diagram of an embodiment of an apparatus for performing multicast on an EPC (core network) according to the present application is shown, where the EPC is configured with a mapping relationship between an IP address of a multicast group and an IP address of a TAU, where the IP address of the multicast group is associated with a display terminal, and the IP address of the TAU is associated with the TAU; the method specifically comprises the following modules:

a receiving module 301, configured to receive a data packet sent by a passenger information system PIS server by the EPC; the data message carries the IP addresses of one or more multicast groups;

a searching module 302, configured to search an IP address of a TAU corresponding to an IP address of the one or more multicast groups;

a sending module 303, configured to send the data packet to one or more TAUs associated with the IP addresses of the one or more TAUs; and the one or more TAUs are used for respectively forwarding the data messages to the display terminals associated with the IP addresses of the multicast group.

In a preferred embodiment of the present invention, the sending module 303 includes:

In a preferred embodiment of the present invention, when the IP address of the TAU corresponding to the IP address of the one or more multicast groups in the routing relation table fails to be looked up, the apparatus further includes:

For the device embodiment, since it is basically similar to the method embodiment, the description is simple, and for the relevant points, refer to the partial description of the method embodiment.

The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

As will be appreciated by one of skill in the art, embodiments of the present application may be provided as a method, apparatus, or computer program product. Accordingly, embodiments of the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

Embodiments of the present application are described with reference to flowchart illustrations and/or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing terminal to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing terminal to cause a series of operational steps to be performed on the computer or other programmable terminal to produce a computer implemented process such that the instructions which execute on the computer or other programmable terminal provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present application have been described, additional variations and modifications of these embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including the preferred embodiment and all such alterations and modifications as fall within the true scope of the embodiments of the application.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or terminal that comprises the element.

The method for performing multicast on the core network EPC and the apparatus for performing multicast on the core network EPC provided by the present application are introduced in detail above, and specific examples are applied in this document to explain the principle and the implementation of the present application, and the description of the above embodiments is only used to help understanding the method and the core idea of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. A method for carrying out multicast on an EPC (core network), which is characterized in that the EPC is provided with a mapping relation between an IP address of a multicast group and an IP address of a TAU (train access unit), wherein the IP address of the multicast group is associated with a display terminal, and the IP address of the TAU is associated with the TAU;

the method comprises the following steps:

2. The method according to claim 1, wherein the mapping relationship between the IP address of the multicast group and the IP address of the train access unit TAU is configured in a newly added multicast address mapping table on a PGW network element side of a packet data node gateway in EPC.

3. The method of claim 1, wherein the mapping between the multicast group IP address and the train access unit TAU IP address is configured in an original routing table in the EPC.

4. The method of claim 1, wherein the step of sending the data packet to one or more TAUs associated with the IP address of the one or more TAUs comprises:

5. The method of claim 3, wherein when finding the IP address of the TAU corresponding to the IP address of the one or more multicast groups in the routing table fails, further comprising:

6. A device for multicast on a core network EPC is characterized in that the EPC is configured with a mapping relation between an IP address of a multicast group and an IP address of a train access unit TAU, wherein the IP address of the multicast group is associated with a display terminal, and the IP address of the TAU is associated with the TAU;

the device comprises:

7. The apparatus according to claim 6, wherein the mapping relationship between the IP address of the multicast group and the IP address of the train access unit TAU is configured in a newly added multicast address mapping table on a PGW network element side of a packet data node gateway in EPC.

8. The apparatus of claim 6, wherein the mapping relationship between the multicast group IP address and the IP address of the Train Access Unit (TAU) is configured in an original routing table in the EPC.

9. The apparatus of claim 6, wherein the sending module comprises:

10. The apparatus of claim 8, wherein when the finding of the IP address of the TAU corresponding to the IP address of the one or more multicast groups in the routing table fails, the apparatus further comprises: