WO2012075832A1

WO2012075832A1 - Multicast data message forwarding method and provider edge device

Info

Publication number: WO2012075832A1
Application number: PCT/CN2011/078670
Authority: WO
Inventors: 邓涛鸿
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-12-09
Filing date: 2011-08-19
Publication date: 2012-06-14
Also published as: CN102025626A; CN102025626B

Abstract

A multicast data message forwarding method and a provider edge device, the method comprising: a provider edge device (PE) receives a user edge device (CE) multicast data message, searches a transmission-multiprotocol label switching (T-MPLS) multicast forwarding table on the basis of the multicast source internet protocol (IP) address and the multicast IP address of the multicast data message, as well as the T-MPLS instance number corresponding to the pseudowire (PW) tunnel, and then copies or discards the multicast data message, wherein the PW user to be copied is contained in the T-MPLS multicast forwarding table; and, the PE, in accordance with PW information table items, then carries out layer 2 label header encapsulation on the copied multicast data message, and transmits the encapsulated multicast data message to a corresponding PE. The technical solution as put forth in the present invention allows for the blocking of multicast messages from unwanted sources or for the precise specification of only certain multicast sources from which multicast data messages shall be received.

Description

Method for forwarding multicast data packets and provider edge device

Technical field

The present invention relates to the field of communications technologies, and in particular, to a method for forwarding multicast data messages and a provider edge device.

Background technique

Transmission-MultiProtocol Label Switching (T-MPLS) is a Multi-Protocol Label Switching (MPLS)-based, connection-oriented packet transmission technology defined by the International Telecommunication Union (ITU-T). The T-MPLS data forwarding plane is a subset of MPLS whose data is forwarded based on T-MPLS labels. T-MPLS is an application of MPLS in transport networks. It simplifies some of the complex functions of the MPLS data forwarding plane and adds connectivity-oriented operations, management, maintenance (OAM) and protection recovery.

Multicast is between unicast and broadcast. It does not need to specify an explicit single recipient like unicast, nor does it send to all recipients in the subnet like a broadcast. The sender is only responsible for generating a multicast data. The network device collects the receiver routing information corresponding to the multicast address and completes the replication and forwarding of the multicast packets. The task of the multicast protocol is to manage the group. Broadcast recipients join and leave, and maintain and update multicast routes (ie multicast forwarding tree).

If there are multiple users in the T-MPLS network that need to receive the same packet, the multicast protocol can be used to copy the packets at one time, saving resources and reducing the usage of the central processing unit (CPU). Currently, in a T-MPLS network, multicast data replication can be implemented simply according to the multicast destination medium access control (MAC) address (or multicast IP address) and the T-MPLS instance number, and the group that the user does not want to receive cannot be masked. The broadcast source cannot accurately specify the multicast data packet that receives a multicast source. Summary of the invention

In order to solve the above technical problem, the present invention provides a method for forwarding a multicast data message and a provider edge device to shield a multicast source that the user does not want to receive or to accurately specify to receive a certain one. Multicast data packet of the multicast source.

The present invention provides a method for forwarding a multicast data packet, the method comprising:

The provider edge device (PE) receives the multicast data packet of the user edge device (CE), and corresponds to the multicast source Internet Protocol (IP) address, multicast IP address, and pseudowire (PW) channel of the multicast data. The transport-multi-protocol label switching (T-MPLS) instance number looks up the T-MPLS multicast forwarding table, and copies or discards the multicast data packet, wherein the T-MPLS multicast forwarding table includes the required Replicated PW user; and

The encapsulated multicast data packet is encapsulated in the Layer 2 label header according to the information of the PW, and the encapsulated multicast data packet is sent to the peer PE.

Preferably, the foregoing method for forwarding a multicast data file has the following characteristics:

The PE establishes a pseudowire (PW) channel with the peer PE.

Preferably, the foregoing method for forwarding a multicast data message may further have the following features:

The foregoing copying or discarding the foregoing multicast data includes:

Determining whether there is a PW multicast user, if yes, copying the multicast data packet to the PW user port; otherwise, discarding the multicast data packet;

The Layer 2 tag header encapsulation of the copied multicast data packet according to the PW information entry includes:

The PW egress information entry corresponding to the PW user port is searched for, and the copied multicast data packet is encapsulated in a Layer 2 tag header.

The present invention further provides a method for forwarding a multicast data packet, the method comprising: the provider edge device (PE) decapsulating the received encapsulated multicast data packet, and parsing the multicast source internet protocol ( IP) address, multicast IP address, and pseudowire (PW) label;

The T-MPLS multicast forwarding table is searched according to the multicast source IP address, the multicast IP address, and the transport-multiprotocol label switching (T-MPLS) instance number corresponding to the PW label, and the multicast data packet is copied or lost. Abandoned, wherein the T-MPLS multicast forwarding table includes a cip user that needs to be copied;

Performing the copied multicast data packet according to the information table entry of the customer instance interface (CIP) The CIP information is encapsulated, and the encapsulated multicast data packet is sent to the user edge device (CE). Preferably, the foregoing method for forwarding a multicast data packet has the following features:

The above-mentioned completion of copying or discarding the above-mentioned multicast data includes:

Determine whether there is a CIP multicast user. If yes, copy the multicast data packet to the CIP user port. Otherwise, discard the multicast data. The CIP information entry is used to copy the multicast data. Packet encapsulation of CIP information includes:

Find the CIP egress information entry corresponding to the CIP user port and encapsulate the CIP information of the copied multicast data packet.

The present invention further provides a provider edge device (ΡΕ), the foregoing device is configured to: receive a multicast data packet of a user edge device (CE), and use a multicast source Internet Protocol (IP) according to the multicast data packet. The address, the multicast IP address, and the transport-multiprotocol label switching (T-MPLS) instance number corresponding to the pseudowire (PW) channel look up the T-MPLS multicast forwarding table, and copy or discard the multicast data packet. The T-MPLS multicast forwarding table includes the PW user to be copied, and the Layer 2 tag header encapsulation of the copied multicast data packet according to the PW information entry, and the encapsulated multicast packet is encapsulated. The data packet is sent to the peer PE.

Preferably, the provider edge device can have the following characteristics:

The foregoing PE is further configured to: establish a PW channel with the peer PE.

Preferably, the provider edge device may also have the following characteristics:

The PE is further configured to: determine whether there is a PW multicast user, if yes, copy the multicast data packet to the PW user port, otherwise discard the multicast data packet; and find the corresponding PW user port. The pw export information entry encapsulates the duplicated multicast data packets in Layer 2 label headers.

The present invention further provides a provider edge device (PE), wherein the PE is configured to: decapsulate the received encapsulated multicast data packet, and parse the multicast source Internet Protocol (IP) address and multicast IP address. Address and pseudowire (PW) label; find the T-MPLS multicast forwarding table according to the multicast source IP address, the multicast IP address, and the transport-multiprotocol label switching (T-MPLS) instance number corresponding to the PW label, and complete the above Copying or discarding multicast data packets, where the above T-MPLS multicast forwarding The publication includes the CIP user to be copied; and the CIP information is encapsulated according to the information table entry of the customer instance interface (CIP), and the encapsulated multicast data is sent to the user edge. On the device (CE).

Preferably, the provider edge device can have the following characteristics:

The foregoing PE is further configured to: determine whether there is a CIP multicast user, and if yes, the foregoing multicast data

The file is copied to the CIP user port. Otherwise, the multicast data is discarded. The CIP egress information entry corresponding to the CIP user port is searched for, and the copied multicast data packet is encapsulated with CIP information.

The method for forwarding the multicast data packet, the upstream PE searches for the T-MPLS multicast forwarding table including the multicast source IP address according to the source IP address, the multicast IP address, and the T-MPLS instance number in the multicast data packet. The multicast data packet is copied and discarded. The encapsulated multicast data packet is sent to the downstream PE according to the PW information entry. After the downstream PE decapsulates the packet, the source IP address is parsed. The multicast IP address and the T-MPLS instance number are used to find the T-MPLS multicast forwarding table that contains the multicast source IP address. The multicast data packet is copied and discarded, and the packet is encapsulated according to the CIP information entry. After the multicast data packet is sent to the CE, the multicast source that the user does not want to receive or the multicast data packet that receives the multicast source can be specified. BRIEF abstract

1 is a schematic flow chart of a multicast join message implemented in a T-MPLS network according to the present invention; FIG. 2 is a flow chart of forwarding multicast data packets on an upstream PE in a T-MPLS network according to the present invention;

FIG. 3 is a flow chart of forwarding multicast data packets on a downstream PE in a T-MPLS network according to the present invention. Preferred embodiment of the invention

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

The basic idea of the embodiment of the present invention is: the multicast source of the upstream PE device according to the multicast data packet The IP address, the multicast IP address, and the T-MPLS instance number are copied or discarded. Then, the PW label, the tunnel label, and the Layer 2 encapsulation are performed. On the downstream PE device, the label is stripped. The multicast source IP address, multicast IP address, and T-MPLS instance number of the multicast data packet are used to perform multicast layer replication.

The present invention provides a method for forwarding a multicast data packet, which is performed by an upstream PE. The method includes:

The foregoing method for copying or discarding the multicast data packet may be: copying or discarding the multicast data packet according to the result of searching the T-MPLS multicast forwarding table.

The present invention also provides a method for forwarding a multicast data packet, which is performed by a downstream PE, and the method includes:

The provider edge device (PE) decapsulates the received encapsulated multicast data packet, and analyzes the multicast source Internet Protocol (IP) address, multicast IP address, and pseudowire (PW) label.

The T-MPLS multicast forwarding table is searched according to the multicast source IP address, the multicast IP address, and the transport-multiprotocol label switching (T-MPLS) instance number corresponding to the PW label, and the multicast data packet is copied or lost. Abandoned, wherein the foregoing T-MPLS multicast forwarding table includes a CIP user that needs to be copied;

The encapsulated multicast data packet is encapsulated with the CIP information, and the encapsulated multicast data packet is sent to the user edge device (CE) according to the information of the customer instance interface (CIP).

The method for forwarding a multicast data packet provided by the embodiment of the present invention is established by identifying a multicast source and The forwarding entry of the T-MPLS instance number, so that users in the T-MPLS network can actually block a multicast source that they do not want to receive or specify to receive a specific multicast source. A T-MPLS multicast forwarding table and a multicast user of the multicast source are used to copy or discard T-MPLS multicast packets.

As shown in FIG. 1 , the flow direction of the forwarding of the multicast packet is implemented in the T-MPLS network of the present invention, where PE1 is the upstream PE and PE2 is the downstream PE.

Assuming that the user edge device (CE) 2 user does not want or only wants to receive a specific multicast source of a certain multicast group, the CE2 user notifies the provider edge device (PE) 2 through the Internet Group Management Protocol (IGMP) protocol, then On the PE2, it is determined whether a PW channel is established between the PE1 and the PE1 of the T-MPLS network edge device. If not, a PW channel is established between the PE1 and the PE2. The multicast source IP address, the multicast IP address, and the T-MPLS instance number corresponding to the PW channel establish a T-MPLS multicast forwarding table. If you want to receive the data of the specific multicast source IP address, you can use CE2 as the Add the user to the T-MPLS multicast forwarding table, and then add the CE2 related client instance interface (CIP) packet encapsulation information entry. If you do not want to receive the multicast data of the specific multicast source IP address, , this CIP user is not added in this T-MPLS multicast forwarding table.

Then, the multicast querier is enabled on the upstream device PE1, and the PW port that receives the multicast join message becomes the multicast user. Similarly, a PW channel is established between PE1 and PE2 on PE1. The multicast source IP address, the multicast IP address, and the T-MPLS instance number corresponding to the PW channel are used to establish a T-MPLS multicast forwarding table. Then, the PW user is added to the T-MPLS multicast forwarding table, and the related PW is added. Packet encapsulation information entry.

On the PE1, all the multicast join messages received from the PW port are analyzed. If all the CE users on the downstream PE2 do not want to receive multicast data packets from a multicast source, the corresponding T- The PW user will not be added to the MPLS multicast forwarding table, and multicast data packets will not be copied to this PW port.

Specifically, the process of forming an entry required for forwarding a multicast join message in the T-MPLS network of the present invention includes the following steps:

Step 101: Configure PW information on PE1 and PE2, and establish a PW channel. Step 102: Send an IGMP multicast join message to the PE2 at the receiving end of the multicast user CE2 or CE3, specify a packet of a specific multicast source that needs a certain multicast, or specify a specific multicast source that does not want to receive a certain multicast. Message

Step 103: The PE2 joins the T-MPLS multicast forwarding table according to the IGMP multicast, and uses the multicast source IP address and the multicast IP address and the T-MPLS instance number corresponding to the PW channel to form a T-MPLS multicast forwarding table. The data packet is added to the T-MPLS multicast forwarding table by the CE2 user or the CE3 user. Otherwise, the CE2 user or the CE3 user is not added to the T-MPLS multicast forwarding table.

Step 104: Form a CIP encapsulation entry on PE2 according to the CIP information configured by CE2 or CE3.

Step 105: Configure a multicast querier on PE1, and receive the multicast information from the PE2 device on PE1.

According to the multicast join message, the T-MPLS multicast forwarding table is formed by using the multicast source IP address, the multicast IP address, and the T-MPLS instance number corresponding to the PW channel; and all the multicast sources received by the PW port are analyzed. If the multicast is not added to the multicast source of the multicast source, the PW user is not added to the corresponding T-MPLS multicast forwarding table; otherwise, the PW port is added. Add to the corresponding T-MPLS multicast forwarding table;

Step 106: Form a PW user encapsulation entry according to the configuration of the PW port on the PE1.

As shown in FIG. 2, the flow of forwarding multicast data packets on the upstream PE in the T-MPLS network of the present invention, the steps of the present invention for forwarding multicast packets from the CE to the PE include:

Step 201: According to the multicast data packet sent by the CE, parse the multicast source IP address and multicast IP address, and use the multicast source IP address, multicast IP address, and T-MPLS instance number to search for T-MPLS. Multicast forwarding table;

Step 202: Determine whether there is a PW multicast user, if yes, go to step 203; otherwise, go to step 204;

Determining whether there is a PW multicast user according to the result of searching the T-MPLS multicast forwarding table; Step 203: Copying the multicast message to the PW user port; Go to Step 205;

For the user to receive multicast data packets of a specific multicast source, the corresponding T-MPLS In the multicast forwarding entry, the PW user is used as the replication user, and the packet is copied to the PW port. Step 204: Discard the multicast data packet;

For the multicast data of a multicast source that you want to block, the PW replication user will be null in the corresponding T-MPLS multicast forwarding entry, that is, the multicast packet will not be copied to the PW. Port

In step 205, the PW egress information entry corresponding to the PW user port is searched, and the copied multicast packet is encapsulated in a Layer 2 tag header and sent to the T-MPLS network.

The structure of the encapsulated multicast data packet is shown in Table 1:

Table 1 Encapsulated multicast data packets

The encapsulated multicast data packet includes information such as a PW label, a tunnel label, a source MAC (SMAC), and a destination MAC (DMAC).

As shown in FIG. 3, in the T-MPLS network of the present invention, a process of forwarding a multicast data packet on a downstream PE is performed. The steps of the present invention for forwarding a multicast packet from the PE to the CE include:

Step 301: According to the multicast data packet sent by the PW, the Layer 2 label header is stripped, and the PW label, the multicast source IP address, and the multicast IP address in the user packet are parsed.

Step 302: Search for a T-MPLS multicast forwarding table by using a multicast source IP address, a multicast IP address, and a T-MPLS instance number corresponding to the PW label.

Step 303: Determine whether there is a CIP multicast user, if yes, go to step 304, otherwise, go to step 305;

Determining whether there is a CIP multicast user according to the result of searching the T-MPLS multicast forwarding table; Step 304: Copying the multicast data packet to the CIP user port; Go to Step 306;

For the user to receive multicast data packets of a specific multicast source, the corresponding T-MPLS The multicast forwarding entry will use this CIP user as the replication user and copy the packet to the CIP port (that is, the CE user).

Step 305: Discard the multicast data packet;

For the multicast data of a multicast source that you want to block, the CIP replication user will be null in the corresponding T-MPLS multicast forwarding entry, that is, the multicast packet will not be copied to this CIP. Port (ie CE user);

Step 306: Search for a CIP egress information entry corresponding to the CIP port, and encapsulate the copied multicast data packet into a CIP information, and send the CIP information to the CE user.

It should be noted that the CIP encapsulation entry, the CIP packet encapsulation information entry, and the CIP egress information entry have the same meaning. The PW user encapsulation entry, the PW packet encapsulation information entry, and the PW export information entry have the same meaning. .

The method for forwarding the multicast data packet, the upstream PE searches for the T-MPLS multicast forwarding table including the multicast source IP address according to the source IP address, the multicast IP address, and the T-MPLS instance number in the multicast data packet. The multicast data packet is copied and discarded. The encapsulated multicast data packet is sent to the downstream PE according to the PW information entry. After the downstream PE decapsulates the packet, the source IP address is parsed. The multicast IP address and the T-MPLS instance number are used to find the T-MPLS multicast forwarding table that contains the multicast source IP address. The multicast data packet is copied and discarded, and the packet is encapsulated according to the CIP information entry. After the multicast data packet is sent to the CE, the multicast source that the user does not want to receive or the multicast data packet that receives the multicast source can be specified.

The present invention also provides a provider edge device (PE), the PE is configured to receive a multicast data packet of a user edge device (CE), and according to the multicast source Internet Protocol (IP) address of the multicast data packet. The multicast-multiple IP address and the transmission-multi-protocol label switching (T-MPLS) instance number corresponding to the pseudowire (PW) channel are used to find the T-MPLS multicast forwarding table, and the multicast data packet is copied or discarded. The T-MPLS multicast forwarding table includes the PW user to be copied; and the Layer 2 tag header encapsulation of the copied multicast data packet according to the PW information entry, and the encapsulated multicast data is encapsulated. The packet is sent to the peer PE.

Preferably, the PE is further configured to establish a PW channel with the peer PE.

Specifically, the foregoing PE may be further used to determine whether there is a PW multicast user, and if yes, The multicast data packet is copied to the PW user port, otherwise, the multicast data packet is discarded; and the PW egress information entry corresponding to the PW user port is searched for, and the duplicated multicast data packet is subjected to a Layer 2 label. Head package.

The PE is the upstream PE. The process of forwarding the multicast data packets sent by the CE to the downstream PE is as shown in Figure 2, and is not mentioned here.

The upstream PE searches for the T-MPLS multicast forwarding table containing the multicast source IP address based on the source IP address, the multicast IP address, and the T-MPLS instance number in the multicast data packet to copy and discard the multicast data packets. The encapsulated multicast data packet is sent to the downstream PE according to the PW information entry.

The present invention also provides a provider edge device (PE), which is used for decapsulating a received encapsulated multicast data packet, and parsing a multicast source Internet Protocol (IP) address and a multicast IP address. And a pseudowire (PW) tag; the T-MPLS multicast forwarding table is searched according to the multicast source IP address, the multicast IP address, and the transport-multiprotocol label switching (T-MPLS) instance number corresponding to the PW label, and the above group is completed. Copying or discarding the broadcast data packet, wherein the T-MPLS multicast forwarding table includes a CIP user to be copied; and the copied multicast data according to the information table entry of the client instance interface (CIP) The CIP information is encapsulated, and the encapsulated multicast data is sent to the user edge device (CE).

Specifically, the PE may be further used to determine whether there is a CIP multicast user, if yes, copy the multicast data to the CIP user port, otherwise, discard the multicast data; and find the CIP user. The CIP egress information entry corresponding to the port encapsulates the CIP information of the copied multicast data packet.

The PE is the downstream PE. The process of forwarding the multicast data packets sent by the upstream PE to the CE is shown in Figure 3, and is not mentioned here.

After decapsulating the encapsulated multicast data packet, the downstream PE searches for the T-MPLS multicast forwarding table containing the multicast source IP address based on the source IP address, multicast IP address, and T-MPLS instance number. The multicast data packet is copied and discarded, and the encapsulated multicast data packet is sent to the CE according to the CIP information entry. This masks the multicast source that the user does not want to receive or specifies the receiving. Multicast data packet of a multicast source.

The above embodiments are only used to illustrate the technical solution of the present invention and are not limited thereto, and only refer to the preferred implementation. The invention has been described in detail by way of examples. A person skilled in the art should understand that the technical solutions of the present invention may be modified or equivalent, without departing from the spirit and scope of the present invention, and should be included in the scope of the claims of the present invention.

Industrial Applicability The above-mentioned method for forwarding a multicast data packet, the upstream PE searches for a T-MPLS group including a multicast source IP address according to the source IP address, the multicast IP address, and the T-MPLS instance number in the multicast data packet. The broadcast forwarding table is used to copy and discard multicast data packets. The encapsulated multicast data packet is sent to the downstream PE according to the PW information entry. After the downstream PE decapsulates the packet, the packet is parsed. The source IP address, the multicast IP address, and the T-MPLS instance number are used to find the T-MPLS multicast forwarding table that contains the multicast source IP address. The multicast data packet is copied and discarded, and the CIP information entry is used. The encapsulated multicast data packet is sent to the CE, so that the multicast source that the user does not want to receive or the multicast data packet that receives the multicast source can be specified.

Claims

Claim

A method for forwarding a multicast data packet, the method comprising:

The provider edge device (PE) receives the multicast data packet of the user edge device (CE), and according to the multicast source Internet Protocol (IP) address, the multicast IP address, and the pseudowire (PW) channel of the multicast data file. The corresponding transport-multi-protocol label switching (T-MPLS) instance number is used to find a T-MPLS multicast forwarding table, and the multicast data packet is copied or discarded, where the T-MPLS multicast forwarding table is Including PW users who need to be replicated;

The method for forwarding a multicast data packet according to claim 1, the method further comprising: establishing, by the PE, a pseudowire (PW) channel with the peer PE.

The method for forwarding a multicast data packet according to claim 1 or 2, wherein the copying or discarding the multicast data file includes:

Determining whether there is a PW multicast user, if yes, copying the multicast data packet to the PW user port; otherwise, discarding the multicast data file;

The PW egress information entry corresponding to the PW user port is searched, and the copied multicast data packet is encapsulated in a Layer 2 tag header.

A method for forwarding a multicast data packet, where the method includes:

The T-MPLS multicast forwarding table is searched according to the multicast source IP address, the multicast IP address, and the transport-multiprotocol label switching (T-MPLS) instance number corresponding to the PW label, and the multicast data packet is copied. Or discarding, wherein the T-MPLS multicast forwarding table includes a cip user that needs to be copied;

Performing the copied multicast data packet according to the information table entry of the customer instance interface (CIP) The CIP information is encapsulated, and the encapsulated multicast data packet is sent to the user edge device (CE).

The method for forwarding a multicast data packet according to claim 4, wherein the completing the copying or discarding of the multicast data file comprises:

Determining whether there is a CIP multicast user, if yes, copying the multicast data packet to the CIP user port, otherwise discarding the multicast data file; the CIP information entry is copied The CIP information encapsulation of the multicast data packet includes:

The CIP egress information entry corresponding to the CIP user port is searched for CIP information encapsulation of the copied multicast data packet.

6. A provider edge device (ΡΕ), wherein

The device is configured to: receive a multicast data packet of a user edge device (CE), and according to the multicast source Internet Protocol (IP) address, multicast IP address, and pseudowire (PW) of the multicast data The transport-multi-protocol label switching (T-MPLS) instance number corresponding to the channel is used to find a T-MPLS multicast forwarding table, and the multicast data packet is copied or discarded, where the T-MPLS multicast forwarding The publication includes the PW user to be copied; and the Layer 2 tag header encapsulation of the copied multicast data packet is performed according to the PW information entry, and the encapsulated multicast data packet is sent to the peer PE.

7. The provider edge device according to claim 6, wherein

The PE is further configured to: establish a PW channel with the peer PE.

8. The provider edge device according to claim 6 or 7, wherein

The PE is further configured to: determine whether there is a PW multicast user, if yes, copy the multicast data packet to the PW user port, otherwise discard the multicast data packet; and find the PW The PW egress information entry corresponding to the user port is encapsulated in the Layer 2 label header of the copied multicast data packet.

9. A provider edge device (PE),

The PE is configured to: decapsulate the received encapsulated multicast data packet, and parse the multicast source Internet Protocol (IP) address, multicast IP address, and pseudowire (PW) label; according to the multicast source IP address. Address, multicast IP address, and transport-multiprotocol label switching (T-MPLS) corresponding to the PW label The instance number is used to find a T-MPLS multicast forwarding table, and the multicast data packet is copied or discarded. The T-MPLS multicast forwarding table includes a CIP user to be copied; and the client instance interface is used. The information of the CIP is encapsulated in the CIP information of the copied multicast data packet, and the encapsulated multicast data packet is sent to the user edge device (CE).

10. The provider edge device according to claim 9, wherein

The PE is further configured to: determine whether there is a CIP multicast user, if yes, copy the multicast data to the CIP user port, otherwise discard the multicast data; and find the The CIP egress information entry corresponding to the CIP user port encapsulates the CIP information of the copied multicast data packet.