WO2009039785A1

WO2009039785A1 - Method and device for establishing multicasting transmission paths and implementing multicasting transmission

Info

Publication number: WO2009039785A1
Application number: PCT/CN2008/072443
Authority: WO
Inventors: Jianping Wu; Wei Cao; Mingwei Xu; Yong Cui; Yuntao Zhou
Original assignee: Huawei Technologies Co., Ltd.; Tsinghua University
Priority date: 2007-09-20
Filing date: 2008-09-22
Publication date: 2009-04-02
Also published as: CN101394298A

Abstract

A method and device for establishing multicasting transmission paths as well as a method and device for implementing multicasting transmission are disclosed. The method for establishing multicasting transmission paths includes: an export PE receiving join request message from an extra customer network (201), the export PE transmitting the join request message to an entry PE on another side of an intra transmission network based on multicasting addresses of the extra customer network (202), the export PE receiving multicasting addresses of the intra transmission network assigned to the multicasting addresses of the extra customer network by the entry PE, and transmitting join request message carrying the multicasting addresses of the intra transmission network in the intra transmission network, as well as establishing the multicasting transmission paths corresponding to the multicasting addresses of the extra customer network in the intra transmission network during the transmission (203), wherein, identifying the multicasting transmission paths with the multicasting addresses of the intra transmission network.

Description

Method and device for establishing multicast transmission path and realizing multicast transmission

This application claims priority to Chinese Patent Application No. 200710154642.7, entitled "Building a Multicast Transmission Path, Method and Apparatus for Realizing Multicast Transmission", submitted to the Chinese Patent Office on September 20, 2007. This is incorporated herein by reference.

Technical field

The present invention relates to the field of network communication technologies, and in particular, to a method and an apparatus for establishing a multicast transmission path and implementing multicast transmission.

Background technique

Currently, with the increasing number of network communication users, the traditional fourth-generation Internet Protocol (IPv4) network has been unable to provide sufficient address space for users to use, based on the sixth generation Internet Protocol (IPv6). The next generation network of Internet Protocol version 6 ) is rapidly evolving. However, since IPv4 networks already have considerable connectivity, and most of the current applications are designed and used in IPv4 networks, IPv4 networks will inevitably exist for a long time in the future. As a result, traditional IPv4 networks are currently formed. The transition phase of the next generation of IPv6 networks is gradually merging. In this transitional phase, with the gradual establishment of the IPv6 network as the backbone network and the gradual abandonment of the IPv4 network, there will be some cases where the IPv4 networks are not connected to each other and need to be interconnected through the intermediate IPv6 transmission network. Of course, correspondingly Some IPv6 networks are disconnected from each other and need to be interconnected through an intermediate IPv4 transport network. This will appear: Protocol (I-IP, Intra Network Internet Protocol) used as an intermediate transport network connecting multiple peripheral client networks and protocols used by peripheral customer networks (E-IP, Extra Network Internet Protocol) Different, that is, there will be a case where the I-IP is IPv4 and the E-IP is IPv6, or the I-IP is IPv6 and the E-IP is IPv4. The protocols used in the intermediate transport network and the peripheral customer network are different from each other, which may cause different peripheral customer networks to communicate with each other through the intermediate transport network.

In order to solve the problems that may occur in the above transition phase, the prior art proposes a multicast translation technology based on address translation. The basic idea of the technology is: at the Provider Edge router (PE), E - IP multicast control packets and multicast data packets are translated into I-IP multicast control messages and multicast data packets, respectively, where the PE router is an edge router between the intermediate transport network and the peripheral customer network. Then, the PE transmits the translated I-IP multicast packet to the I-IP network, and then restores the packet to the corresponding E-IP multicast packet when the packet reaches the egress PE. The message continues to be transmitted over the E-IP network. By transmitting the translated I-IP multicast message in the I-IP network, E-IP multicast data can be established on the transport provider router (P, Provider router) of the I-IP network. The I-IP multicast tree of the transport service. An E-IP multicast tree corresponds to an I-IP multicast tree in the I-IP network. These two multicast trees are essentially different representations of the multicast tree in different protocols. The translation adopts a pre-agreed unified format, so that each PE can be identified, so that mutual negotiation between the PEs is not required.

The above translation process is described in detail below. For example, when the protocol running on the intermediate transport network is IPv6 and the protocol running on the peripheral client network is IPv4, the format of the translation is as shown in FIG. 1 , where the IPv6 prefix is a specific IPv6 address prefix, so that the PE router receives the prefix. After the IPv6 address, it can be handed over to the corresponding restore module for processing. The specific address prefix can be obtained through address allocation or internally configured by an Internet Service Provider (ISP). The translation and restoration process is as follows:

Translation: The part of the destination network address in the IPv4 unicast or multicast routing table, in the form a.b.c.d/M, where M is the bit length of the mask. According to the 4over6 address mapping, it can be transformed into a pseudo IPv6 address: 4over6prefix: a.b.c.d /len+M. 4over6prefix/len is a pseudo-IPv6 address-specific prefix with a length of len. The pseudo-IPv6 address-specific prefix can be obtained through address allocation, or can be allocated and managed by an ISP, so that all PEs can be identified without negotiation.

Restore: The 4over6 border router uses the pseudo IPv6 address prefix 4over6prefix/len to prefix match the destination address. If the prefix within the len prefix length is the same, then the IPv6 route is determined to be a pseudo IPv6 route, and then the inverse transform of the 4over6 route conversion is performed. Perform a route restore.

Although the above multicast transition technology can establish a multicast transmission path under the condition that I-IP and E-IP are different, and use the path to implement network communication of the peripheral customer network through the intermediate transmission network, the technology still has the following disadvantages. :

In order to establish a corresponding transmission path in the intermediate transmission network in the case where I-IP and E-IP are different, translation from E-IP to I-IP is required, when the E-IP protocol type is IPv4 and I-IP When the protocol type is IPv6, it is easier to translate the IPv4 address of the E-IP into the IPv6 address of the I-IP. Since the IPv6 address has 128 bits, the translation can be combined by a 32-bit IPv4 address and a 96-bit specific IPv6 prefix. Form a 128-bit pseudo IPv6 address; however, when the E-IP protocol type is IPv6 and the I-IP protocol type is IPv4, the IPv4 address is 32 bits and the IPv4 address is 32 bits, unless it is added. The complex inter-PE address negotiation mechanism adds a specific domain to the protocol packet. Otherwise, the 128-bit IPv6 address cannot be translated into a 32-bit IPv4 address, which makes the technical solution more complicated to implement.

In addition, since the above translation and restoration need to follow the pre-established rules, and the routing of I-IP multicast control messages obtained by E-IP translation in the I-IP network needs to add an additional addressing mechanism, I-IP The intermediate P router of the transport network also needs to support this addressing mechanism accordingly, which also brings great implementation difficulty to the implementation of the above prior art.

Summary of the invention

The purpose of the embodiments of the present invention is to provide a method and a device for establishing a multicast transmission path and implementing multicast transmission, so as to enable a multicast transmission path and implementation of the intermediate transmission network to be established without using the above translation mechanism. Multicast transmission.

In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:

A method for establishing a multicast transmission path, the method comprising:

Receiving a request to join the packet from the peripheral client network, where the request join message includes a multicast address of a peripheral client network of the multicast group that requests to join;

And sending, according to the peripheral client network multicast address, the request join message to an entry PE located on the other side of the intermediate transport network and corresponding to the peripheral client network multicast address;

Receiving, by the ingress PE, an intermediate transport network multicast address allocated by the peripheral client network multicast address, and transmitting, in the intermediate transport network, a request join message carrying the intermediate transport network multicast address, and utilizing The multicast transmission path corresponding to the multicast address of the peripheral client network is established in the intermediate transmission network during the transmission of the intermediate transmission network by the request-joining message carrying the multicast address of the intermediate transmission network; The multicast transmission path is identified by the intermediate transmission network multicast address.

A device for establishing a multicast path, the device comprising:

The first packet transmission unit is configured to send, after receiving the request to join the packet, the peripheral client network carrying the multicast address of the peripheral client network, sending the request join message to the located address according to the multicast address of the peripheral client network An ingress PE corresponding to the other side of the intermediate transmission network and corresponding to the peripheral client network multicast address;

a message processing unit, configured to receive an intermediate transport network multicast address allocated by the ingress PE for the peripheral client network multicast address, and construct a request join message carrying the intermediate transport network multicast address; a second packet transmission unit, configured to add the request carrying the intermediate transmission network multicast address to the intermediate transmission network for transmission, to use the request to join the transmission process of the text in the intermediate transmission network, in the middle A multicast transmission path corresponding to the multicast address of the peripheral client network is established in the transport network, where the multicast transmission path is identified by the intermediate transport network multicast address.

A device for establishing a multicast path, the device comprising:

a multicast address allocation unit, configured to allocate a corresponding intermediate transmission network multicast address to the peripheral client network multicast address after receiving the request for adding the multicast address of the peripheral client network sent by the egress PE;

The address sending unit is configured to send the intermediate transmission network multicast address allocated by the multicast address allocation unit to the egress PE through signaling of the intermediate transmission network.

A method for implementing multicast transmission, the method comprising:

Receiving the peripheral client network multicast data packet sent by the peripheral client network, according to the peripheral client network multicast address carried in the packet, and the locally stored peripheral client network multicast address and the corresponding intermediate transport network multicast address. Corresponding relationship, determining an intermediate transmission network multicast address corresponding to the peripheral client network multicast address;

Determining, according to the determined intermediate transmission network multicast address, a multicast transmission path in the intermediate transmission network corresponding to the intermediate transmission network multicast address, and passing the peripheral client network multicast data packet through the group The broadcast transmission path is sent to the corresponding egress PE.

A device for implementing multicast transmission, the device comprising:

a multicast data packet receiving unit, configured to receive a peripheral client network multicast data packet from a peripheral client network, where the peripheral client network multicast data packet includes a peripheral client network multicast address;

Corresponding relationship storage unit, configured to store a correspondence between a peripheral client network multicast address and an intermediate transport network multicast address allocated for the peripheral client network multicast address;

a multicast transmission path determining unit, configured to: according to the peripheral client network multicast address in the peripheral client network multicast data packet, and the peripheral client network multicast address stored in the corresponding relationship storage unit and the corresponding intermediate transport network multicast Corresponding relationship of the address, determining an intermediate transmission network multicast address corresponding to the peripheral client network multicast address, and determining a group in the intermediate transmission network corresponding to the intermediate transmission network multicast address according to the intermediate transmission network multicast address Broadcast transmission path;

a multicast data packet sending unit, configured to encapsulate the peripheral client network multicast data packet into the middle After transmitting the multicast data packet, the multicast transmission path in the intermediate transmission network is sent to the corresponding egress PE.

It can be seen that, in the embodiment of the present invention, the corresponding intermediate transmission network multicast address is allocated to the peripheral client network multicast address, and the request carrying the intermediate transmission network multicast address is added to the message and transmitted in the intermediate transmission network. This makes it possible to establish a multicast transmission path in the intermediate transmission network without performing translation between different network protocols, thereby effectively avoiding the prior art, since the multicast address is translated from IPv6 to IPv4 or from IPv4 to IPv6. The technology that is brought about achieves complex problems. It is foreseeable that with the popularity of video streaming, web conferencing and other multimedia network applications, multicast technology will gain more and more applications. At the same time, since the IPv4 network and the IPv6 network will coexist for a long time, it is of high practical significance to solve the problem of establishing a multicast transmission path when the multicast data crosses different protocols. The embodiment of the present invention provides a feasible implementation manner, and does not need to upgrade a large number of non-edge routers in the intermediate transmission network, has good operability, and can fully save costs in the implementation process, and is beneficial to multicast. Rapid use of technology.

DRAWINGS

1 is a translation format used in the translation of different network protocols in the prior art; FIG. 2 is a flowchart of a method for establishing a multicast transmission path according to an embodiment of the present invention;

3 is a flowchart of a method for establishing a multicast transmission path according to another embodiment of the present invention; FIG. 4 is a schematic diagram of an apparatus for establishing a multicast transmission path according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an apparatus for establishing a multicast transmission path according to another embodiment of the present invention; FIG. 6 is a flowchart of a method for implementing multicast transmission according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of an apparatus for implementing multicast transmission according to an embodiment of the present invention.

detailed description

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 2, in an embodiment of the present invention, the implementation of establishing a multicast transmission path includes the following steps: Step 201: An egress router edge router (ΡΕ) receives a request to join a message from a peripheral client network, where An edge router is located between the intermediate transport network and the peripheral client network, and the request join message includes a multicast address of a peripheral client network of the multicast group that requests to join;

Step 202: The egress port determines, according to the multicast address of the peripheral client network, that the multicast source is located in a peripheral client network connected to the other side of the intermediate transport network, and joins the request. 4艮文 is sent to the entry PE;

Step 203: The egress PE receives the intermediate transport network multicast address allocated by the ingress PE for the peripheral client network multicast address, and transmits a request carrying the intermediate transport network multicast address in the intermediate transport network. Adding a message, and establishing a multicast transmission path corresponding to the multicast address of the peripheral client network in the intermediate transmission network during the process of transmitting the request to join the intermediate transmission network; wherein the multicast transmission path It is identified by the intermediate transmission network multicast address.

In the preferred embodiment of the present invention, in order to implement the transmission of the multicast data in the peripheral client network, the method for establishing the multicast transmission path may further include:

After receiving the request to join the packet, the ingress PE determines, according to the intermediate transmission network multicast address carried in the packet, the corresponding peripheral client network multicast address, and connects to the peripheral client connected thereto. The network sends a request to join the packet carrying the peripheral client network multicast address, and in the process of transmitting the message in the peripheral client network, the group corresponding to the peripheral client network multicast address is established in the peripheral client network. Broadcast transmission path.

The method for establishing a multicast transmission path is described in detail below with reference to specific examples. For convenience of presentation, the address of the multicast source included in the multicast address of the peripheral client network is represented by s, and the address of the multicast group included in the multicast address of the peripheral client network is represented by g, to join (s, g) indicates that the peripheral client network requests to join the message; g indicates the intermediate transmission network multicast address, and s indicates the intermediate transmission network address of the ingress PE, with join(s,, g ,) indicates that the intermediate transmission network requests to join the text.

Referring to FIG. 3, in an embodiment of the present invention, implementing a multicast transmission path for establishing an intermediate transmission network includes the following steps:

Step 301: The join(s, g) packet of the E-IP network reaches the egress PE directly connected to it;

Step 302: The egress PE finds that the multicast source corresponding to the s is located on the other side of the intermediate transmission network, and determines, according to the s, the PE connected to the peripheral client network where the multicast source is located. , the PE is the ingress PE;

Step 303: The egress PE sends a request join message (s, g) to the ingress PE through I-IP signaling, where the multicast address (s, g) in the E-IP format is E-IP format. Multicast address, which is the multicast address of the peripheral client network;

Step 304: After receiving the join (s, g) message, the ingress PE is a multicast for the peripheral client network. The address (s, g) is assigned a corresponding I-IP multicast address g, that is, an intermediate transport network multicast address, and the corresponding relationship between (s, g) and g is recorded locally;

Step 305: The ingress PE sends the intermediate transmission network multicast address g to the egress PE through I-IP signaling through the intermediate transmission network.

Step 306: The egress PE receives the intermediate transmission network multicast address g, and then sends a request to join the packet to the ingress PE through the intermediate transmission network, where the request packet carries at least the intermediate transmission network group. The broadcast address g, in the preferred embodiment of the present invention, the multicast source address of the packet is the I-IP address s of the ingress PE in the intermediate transport network; the 4艮 text is represented as join(s,, g ,); in the join (s,, g') 3⁄4 text in the middle of the transmission network transmission process, establish a multicast corresponding to the peripheral customer network multicast address (s, g) in the intermediate transmission network The transmission path, which is the multicast tree, completes the process of establishing a multicast transmission path in the intermediate transmission network.

In a preferred embodiment of the present invention, the method for establishing a multicast transmission path may further include the following steps:

Step 307: After receiving the join (s, g,) message, the ingress PE searches for the corresponding relationship recorded in step 304, so as to find the corresponding multicast address g of the intermediate transmission network. Peripheral customer network multicast address (s, g);

Step 308: The ingress PE sends a request to join the packet carrying the peripheral client network multicast address ( _s , g) to the E-IP network connected thereto, that is, the peripheral client network, where the packet is on the periphery. During the transmission of the client network, the multicast transmission path corresponding to the multicast address (s, g) of the peripheral client network is established in the peripheral client network.

Through the above steps 301~308, the corresponding multicast transmission path can be established simultaneously in the peripheral client network and the intermediate transmission network. Among them, the process of establishing a multicast transmission path in different networks is independent of each other.

Correspondingly, for the foregoing method for establishing a multicast path, the embodiment of the present invention further provides an apparatus for establishing a multicast path. Referring to FIG. 4, in an embodiment of the present invention, the apparatus includes:

a first message transmission unit 401, configured to: after receiving a request to join a message from a peripheral client network carrying a multicast address of a peripheral client network, adding the request according to the multicast address of the peripheral client network The message is sent to the ingress PE located on the other side of the intermediate transmission network;

a message processing unit 402, configured to: receive the ingress PE as the peripheral client network group An intermediate transmission network multicast address allocated by the broadcast address, and a request for carrying the intermediate transmission network multicast address is added to join the message;

a second message transmission unit 403, configured to: add the request carrying the intermediate transmission network multicast address to the intermediate transmission network for transmission, to use the request to join the transmission of the message in the intermediate transmission network The multicast transmission path corresponding to the multicast address of the peripheral client network is established in the intermediate transmission network, where the multicast transmission path is identified by the intermediate transmission network multicast address.

The apparatus shown in FIG. 4 corresponds to the egress PE described in the embodiment of the present invention. Referring to FIG. 5, in another embodiment of the present invention, the apparatus provided by the embodiment of the present invention includes: The broadcast address assigning unit 501 is configured to allocate a corresponding intermediate transport network multicast address to the peripheral client network multicast address after receiving the request to join the packet sent by the egress PE and carrying the peripheral client network multicast address;

The address sending unit 502 is configured to send the intermediate transport network multicast address allocated by the multicast address allocating unit 501 to the egress PE through signaling of the intermediate transport network.

In a preferred embodiment, the device may further include:

The correspondence relationship storage unit 503 is configured to store a correspondence between the peripheral client network multicast address and the intermediate transport network multicast address allocated by the multicast address allocation unit to the peripheral client network multicast address.

The embodiment of the invention further provides a method and a device for implementing multicast transmission, and the method and the device are described in detail below with reference to specific examples.

Referring to FIG. 6, in the embodiment of the present invention, a method for implementing multicast transmission includes the following steps: Step 601: The ingress PE receives a peripheral client network multicast data packet sent by the peripheral client network, according to the packet carried in the packet. a peripheral client network multicast address, and a correspondence between a peripheral client network multicast address stored in the ingress PE and a corresponding intermediate transport network multicast address, and determining an intermediate transport network multicast address corresponding to the peripheral client network multicast address;

Step 602: The ingress PE is used to determine the intermediate transmission network multicast address, determine a multicast transmission path in the intermediate transmission network corresponding to the intermediate transmission network multicast address, and multicast the peripheral customer network. After the data packet is encapsulated into an intermediate transport network multicast data packet, the data packet is sent to the corresponding egress PE through the multicast transmission path;

In a preferred embodiment of the present invention, the method for implementing the multicast transmission may further include: after the egress PE receives the multicast data packet of the intermediate transmission network, the packet is decapsulated The peripheral client network multicast data packet is loaded, and the peripheral client network multicast data packet is forwarded in the peripheral client network until reaching the corresponding destination device.

Corresponding to the method for implementing multicast transmission provided by the embodiment of the present invention, in the embodiment of the present invention, an apparatus for implementing multicast transmission is further provided. Referring to FIG. 7, the apparatus includes:

The multicast data packet receiving unit 701 is configured to receive a peripheral client network multicast data packet from the peripheral client network, where the peripheral client network multicast data packet includes a peripheral client network multicast address;

Correspondence relationship storage unit 702, configured to store a correspondence between a peripheral client network multicast address and an intermediate transport network multicast address allocated for the peripheral client network multicast address;

The multicast transmission path determining unit 703 is configured to: according to the peripheral client network multicast address carried in the peripheral client network multicast data packet, and the peripheral client network multicast address and the corresponding intermediate transmission network stored by the correspondence relationship storage unit 702 Corresponding relationship of the multicast address, determining an intermediate transmission network multicast address corresponding to the peripheral client network multicast address, and determining the intermediate transmission network multicast address to be determined in the intermediate transmission network corresponding to the intermediate transmission network multicast address Multicast transmission path;

The multicast data packet sending unit 704 is configured to encapsulate the peripheral client network multicast data packet into an intermediate transport network multicast data packet, and determine, by using the determined multicast transmission path in the intermediate transport network The corresponding egress PE sends.

Therefore, in the embodiment of the present invention, the corresponding intermediate transmission network multicast address is allocated to the peripheral client network multicast address, and the request carrying the intermediate transmission network multicast address is added to the intermediate transmission network. The medium transmission enables the establishment of a multicast transmission path in the intermediate transmission network without performing translation between different network protocols, thereby effectively avoiding the translation of the multicast address from IPv6 to IPv4 or from IPv4 in the prior art. The technology brought about by IPv6 implements complex problems. It can be foreseen that with the continuous popularization of various multimedia network applications such as live video broadcasting and web conferencing, multicast technology will be more and more applied. At the same time, since the IPv4 network and the IPv6 network will coexist for a long time, it is of high practical significance to solve the problem of establishing a multicast transmission path when multicast data crosses different protocols. The embodiments of the present invention provide a feasible implementation solution, which does not require upgrading a large number of non-edge routers in the intermediate transmission network, has good operability, and can fully save costs in the implementation process, and is beneficial to multicast. Rapid use of technology.

The above description is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present invention. These improvements and finishes should also be considered as protection of the present invention.

Claims

Rights request

A method for establishing a multicast transmission path, the method comprising:

2. The method according to claim 1, wherein the transmitting the request join message to an ingress PE located on the other side of the intermediate transport network and corresponding to the multicast address of the peripheral client network For:

By finding the local routing information, determining that the multicast source corresponding to the multicast address of the peripheral client network is located on the other side of the intermediate transmission network, and determining that the multicast source is corresponding according to the address of the multicast source. Entrance PE;

The request is sent to the ingress PE through signaling of the intermediate transport network.

The method according to claim 1 or 2, wherein the method further comprises: the ingress PE recording the peripheral client network multicast address and the intermediate transport network multicast address allocated for the multicast address Correspondence between them.

The method according to claim 1 or 2, wherein the method further comprises: after receiving the request carrying the multicast address of the intermediate transmission network, the ingress PE joins the packet according to the method The intermediate transmission network multicast address carried in the message is determined to obtain a corresponding peripheral client network multicast address, and the request to the peripheral client network connected thereto is sent to carry the request for the multicast address of the peripheral client network. And in the process of transmitting the peripheral client network by using the request to join the packet with the peripheral client network multicast address, establishing a multicast transmission corresponding to the peripheral client network multicast address in the peripheral client network path.

5. A device for establishing a multicast path, the device comprising: The first packet transmission unit is configured to send, after receiving the request to join the packet, the peripheral client network carrying the multicast address of the peripheral client network, sending the request join message to the located address according to the multicast address of the peripheral client network An ingress PE corresponding to the other side of the intermediate transmission network and corresponding to the peripheral client network multicast address;

a packet processing unit, configured to receive an intermediate transport network multicast address allocated by the ingress PE for the peripheral client network multicast address, and construct a request join message carrying the intermediate transport network multicast address;

a second packet transmission unit, configured to add the request carrying the intermediate transmission network multicast address to the intermediate transmission network for transmission, to use the request to join the transmission process of the text in the intermediate transmission network, in the middle A multicast transmission path corresponding to the multicast address of the peripheral client network is established in the transport network, where the multicast transmission path is identified by the intermediate transport network multicast address.

6. A device for establishing a multicast path, the device comprising:

7. The device according to claim 6, further comprising:

The correspondence relationship storage unit is configured to store a correspondence between the peripheral client network multicast address and the intermediate transport network multicast address allocated by the multicast address allocation unit to the peripheral client network multicast address.

8. A method for implementing multicast transmission, the method comprising:

Determining, according to the determined intermediate transmission network multicast address, a multicast transmission path in the intermediate transmission network corresponding to the intermediate transmission network multicast address, and transmitting the peripheral client network multicast data packet through the multicast The transmission path is sent to the corresponding egress PE.

9. The method according to claim 8, wherein the method further comprises:

After the egress PE receives the intermediate transmission network multicast data packet, the egress network from the intermediate transmission network A multicast client network multicast data packet is obtained in the multicast data packet, and the peripheral client network multicast data packet is forwarded on the peripheral client network.

10. A device for implementing multicast transmission, characterized in that the device comprises:

a multicast data packet sending unit, configured to encapsulate the peripheral client network multicast data packet into an intermediate transport network multicast data packet, and determine, by using the determined multicast transmission path in the intermediate transport network The exit PE is sent.