WO2007054006A1 - A base station of wideband wireless access system and a method for realizing group-broadcast service - Google Patents

Abstract

A base station (BS) of wideband wireless access system includes: message obtaining module used for obtaining the group-broadcast protocol message between user station and router; group-broadcast address forwarding list maintaining module used for maintaining group-broadcast address forwarding list according to the type of obtained message; establishing group-broadcast module used for distributing same connection sign for all the user stations in the group-broadcast group, and managing the said user stations n the group-broadcast group according to the connection sign and maintained group-broadcast address forwarding list. A method for realizing group-broadcast service in wideband wireless access system includes the following steps: obtaining the group-broadcast protocol message between user station and router and maintaining group-broadcast address forwarding list according to the type of obtained message; distributing same connection sign for all the user stations in the group-broadcast group and managing the said user stations n the group-broadcast group according to the connection sign and maintained group-broadcast address forwarding list. Both the BS and the method provided in the invention can save bandwidth resource in the air.

Description

 Base station in broadband wireless access system and method for realizing multicast service

 The present invention relates to a broadband wireless access system, and in particular to a base station in a broadband wireless access system and a method thereof for implementing a multicast service. Background of the invention

 Traditional Internet Protocol (IP) communication (such as IPv4 communication) is performed between a source IP host and a target IP host (unicast) or between a source IP host and all IP hosts in the network (broadcast). If you want to send information to multiple, but not all, IP hosts in your network, either use broadcast mode or the source IP host sends IP packets to multiple target IP hosts in the network. The former method wastes bandwidth by sending information to a large number of IP hosts that should not be involved, and may also cause broadcast storms due to route loopback; the latter method wastes a lot of bandwidth due to repeated transmission of IP packets, and Increase the load on the server.

 It can be seen that the traditional IP communication technology cannot effectively solve the problem of single-point transmission and multi-point reception.

 With the development of communication technology, the subsequent IP multicast technology allows the source IP host to send IP packets to any set of target IP hosts on the IP network, which can effectively solve single-point transmission, multi-point reception and multiple points. The problem of sending and receiving multiple points has been widely used in multimedia conferencing, data distribution, distributed parallel processing, and distributed interactive simulation.

Referring to FIG. 1, FIG. 2, and FIG. 3, FIG. 1, FIG. 2, and FIG. 3 respectively show the data streams of the broadcast mode, the unicast mode, and the multicast mode in the existing IP communication technologies, and these data flows are all in the router, The base station, the subscriber station, and the user are respectively transmitted in the form of corresponding broadcast, unicast, and multicast. In a broadband wireless access system, such as the IEEE 802.16 standard of the Worldwide Interoperability for Microwave Access Interoperability (WiMAX), when a multicast packet needs to be sent to a user host on the network side, The base station (BS) device receives the multicast packet whose destination media access control (MAC) address is the multicast MAC address. The BS device cannot find the output port through Layer 2 learning. ^ for the received multicast packet processing ^method employed is usually Gen following two:

 a. Broadcast the multicast packet to all Subscriber Stations (SSs), even if only one of the SSs needs the multicast packet. This implementation method is relatively simple, but it also has disadvantages: it increases the processing load of the receiver that does not need the multicast packet, and increases the power consumption of the SS device. In addition, the host that does not join the multicast group can also receive The multicast packet is easy to generate security risks.

 The multicast packet is converted into a unicast packet and sent to the corresponding SS according to a certain rule. Only the SS that needs the multicast packet receives the multicast packet. However, in this implementation method, the BS device or other device is required to implement the multicast replication function, which increases the complexity of the device. For example, if there are many SSs in the multicast group, the packets need to be copied one by one. Each SS; this will increase the complexity of the BS device, and also obviously waste the bandwidth resources of the air interface, and the traffic generated by the copy operation is also likely to become a bottleneck of network performance. Summary of the invention

 In view of this, the main object of the present invention is to provide a base station in a broadband wireless access system to save air interface bandwidth resources.

 Another object of the present invention is to provide a method for implementing a multicast service in a broadband wireless access system to save air interface bandwidth resources.

In order to achieve the above object, the technical solution of the present invention is achieved as follows: The invention discloses a base station in a broadband wireless access system, which is connected with a router and a subscriber station, and the base station comprises:

 a packet obtaining module, configured to obtain a message between the user station and the router;

 The multicast address forwarding table maintenance module is configured to maintain a multicast address forwarding table according to the type of the obtained packet;

 The multicast service establishing module is configured to allocate a same connection identifier to all user stations in the multicast group, and the connection identifier and the maintained multicast address forwarding table manage the user stations in the multicast group.

 The packet obtaining module includes a listening module and/or a proxy module;

 The interception module is configured to listen to the message between the user station and the router;

 A proxy module that intercepts packets between the subscriber station and the router.

 The listening module is an IGMP snooping module for IPv4 or a multicast Listener Discovery (MLD) listening module for an IPv6 network;

 The proxy module is an IGMP proxy module for IPv4 or an MLD proxy module for IPv6.

 The packets intercepted or intercepted by the IGMP snooping module and the IGMP proxy module include: an IGMP query message from the router, an IGMP report message from the user station, and an IGMP leave message.

 The IGMP snooping module and the IGMP proxy module are used to:

 When listening to or intercepting the IGMP query message, determining a port of the base station device connected to the router;

 When the IGMP report message is intercepted or intercepted, it is determined whether the port is added to the multicast group or the multicast group forwarding table is created according to the port that receives the IGMP report message and the group in the IGMP report message.

When listening to or intercepting the IGMP Leave message, leaving by receiving the IGMP ^= The port of the text sends a group query message.

 The MLD snooping module and the MLD proxy module listen to or intercept the packet, including: a group membership query message, a group membership report message, and a group membership reduction message message.

 The group user station management performed by the multicast service establishing module is implemented by a multicast forwarding execution module connected to the multicast service establishing module.

 The invention also discloses a method for implementing a multicast service in a broadband wireless access system, the method comprising:

 Obtain the packet transmitted between the user station and the router, and maintain the multicast address forwarding table according to the type of the obtained packet; assign the same connection identifier to all user stations in the multicast group, according to the connection identifier and the maintenance The multicast address forwarding table manages user stations in a multicast group.

 The method for obtaining the packet is as follows: Listening or intercepting the packet between the user station and the router. The interception operation is performed by: an IGMP snooping module for IPv4 or an MLD snooping module for an IPv6 network;

 The interception operation is performed: an IGMP proxy module for IPv4 or an MLD proxy module for IPv6.

 For an IPv4 network, the packet is an IGMP Query message, an IGMP report message, or an IGMP Leave message.

 For an IPv6 network, the message is a group membership query message, a group membership report message, or a group membership reduction message message.

The operation of the user station in the management multicast group is a multicast establishment. The multicast establishment method includes: acquiring an IGMP report message transmitted between the user station and the router, and querying according to the multicast number in the obtained IGMP report message. Whether the multicast group exists in the multicast address forwarding table. If it does not exist, create a multicast group forwarding table and add the source user station device to the multicast group forwarding table. The information is also assigned a new connection identifier and the egress in the newly created multicast group forwarding table is set as the connection identifier; the source subscriber station device is also notified to receive the packet containing the connection identifier.

 The operation of the user station in the management multicast group is a multicast join. The multicast join method includes: acquiring an IGMP report message transmitted between the user station and the router, and querying according to the multicast number in the obtained IGMP report message. Whether the multicast group exists in the multicast address forwarding table. If yes, the source user station device information is added to the multicast address forwarding table to obtain the egress connection identifier. The source user station device is also notified to receive the report including the connection identifier. Text.

 The operation of the user station in the management multicast group is a multicast leaving. The multicast leaving method includes: acquiring an IGMP Leave message sent between the user station and the router, and obtaining the multicast group number in the received IGMP Leave message. Querying the multicast address forwarding table, deleting the source user station setting information in the multicast address forwarding table, and obtaining the egress connection identifier information; and notifying the source user station device not to receive the 4 艮 text including the connection identifier;

 Determining whether there is a subscriber station device in the multicast address forwarding table, if not, not processing; and receiving the packet from the multicast group when receiving the packet of the multicast group from the network side, The text is sent out.

 The operation of the user station in the management multicast group is a multicast deletion. The multicast deletion method includes: acquiring an IGMP Leave message sent between the user station and the router, and obtaining the multicast group number in the IGMP Leave message according to the obtained Querying the multicast address forwarding table, deleting the source user station device information in the multicast address forwarding table, and obtaining the egress connection identifier information; and notifying the source user station device that the packet containing the connection identifier is not received;

 Determining whether there is a user station device in the multicast address forwarding table, if not, deleting the multicast address forwarding table, and retrieving the connection identifier; and discarding the received packet when receiving the packet of the multicast group from the network side The message arrived.

Compared with the prior art, the base station provided in the broadband wireless access system and the method for implementing the multicast service can effectively reduce the SS power consumption and ensure the communication security, and The complexity of the BS device is reduced, and the air interface bandwidth resource is saved. BRIEF DESCRIPTION OF THE DRAWINGS

 Figure 1 is a schematic diagram of a packet transmission in an IPv4/IPv6 network. Figure 2 is a schematic diagram of another packet in a unicast mode in an IPv4/IPv6 network. Figure 3 is IPv4/IPv6. A schematic diagram of another type of packet in the network for multicast mode delivery; FIG. 4 is a schematic diagram of a layered system of multicast protocols;

 FIG. 5 is a flow chart of IGMP snooping according to a preferred embodiment of the present invention; FIG.

 Figure 6 is a flow diagram of an IGMP proxy in accordance with a preferred embodiment of the present invention. Mode for carrying out the invention

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

 The base station in the broadband wireless access system provided by the present invention is connected to a router and a user station, and the base station includes: a packet acquisition module, configured to acquire a packet between the user station and the router; and a multicast address forwarding table maintenance module And the multicast service forwarding module is configured to allocate a same connection identifier to all user stations in the multicast group according to the connection identifier and the maintenance, according to the type of the obtained packet. The multicast address forwarding table manages the user stations in the multicast group.

 The method for implementing a multicast service in a broadband wireless access system provided by the present invention includes: acquiring a packet transmitted between a user station and a router, and maintaining a multicast address forwarding table according to the type of the obtained packet; All subscriber stations in the network are assigned the same connection identifier, and the subscriber stations in the multicast group are managed according to the connection identifier and the maintained multicast address forwarding table.

The term "host" as used in the present invention refers to a node (non-router) that cannot forward a BP packet that is not explicitly addressed to itself. Typically, the host is the source and destination node for IP traffic; and, the host can discard the traffic it receives that is not explicitly addressed to itself. Figure 1 to The user host in Figure 3 can be considered a form of host.

 Referring to the multicast protocol layering system shown in Figure 4, it can be seen that the Internet Group Management Protocol (IGMP) is at the lowest level of the multicast i" protocol, and is the entire multicast protocol. IGMP is used to dynamically manage the situation where a router joins or leaves a multicast group, and establishes a Layer 3 multicast address forwarding table. In the multicast protocol, only the IGMP protocol directly contacts the on-demand host, and the router running IGMP is responsible for management. A host that is a member of a group joins and leaves a multicast group. It can also perform group member state maintenance and send multicast data to the host.

 The base station device provided by the present invention at least includes: a packet obtaining module, a multicast address forwarding table maintenance module, a multicast service establishing module, and a multicast forwarding executing module.

 The packet obtaining module includes a listening module and/or a proxy module. Specifically, the listening module may be an IGMP Snooping module used in an IPv4 network or an MLD listening module for an IPv6 network; the proxy module may be an IGMP proxy (IGMP Proxy) module or an MLD proxy. Module.

 The IGMP snooping module listens for IGMP messages transmitted between the SS and the router, and the base station device maintains the Layer 2 multicast address forwarding table.

 The IGMP proxy module can intercept IGMP messages between the SS and the router, and the base station device maintains the Layer 2 multicast address forwarding table. Moreover, the uplink port of the IGMP proxy module performs the role of the host, and the downlink port performs the role of the router. Specifically, the uplink port of the IGMP proxy module performs the role of the host, and responds to the query from the router. When the newly added user group or the last user of a multicast group exits, the IGMP proxy module actively sends a member report packet to the router or leaves the router. package. The downlink port of the IGMP proxy module performs the role of the router, which is completely implemented according to the mechanism specified in IGMP V2, such as: querier election, regular general query information, and specific query when receiving leave messages.

The main difference between the IGMP snooping module and the IGMP proxy module is that the IGMP proxy module Different functions are implemented on the two ports, and the workload is relatively large. The advantages are: The IGMP proxy module can function as a querier when there is no router in the network, and the IGMP proxy module can be more convenient than the IGMP snooping module. Extended multicast routing.

 The multicast service establishment module can implement functions such as multicast establishment, multicast join, multicast leave, and multicast deletion. Of course, the multicast service setup module needs to obtain related information from the multicast address forwarding table maintenance module when implementing the above functions. .

 The multicast forwarding execution module is used to implement a specific multicast forwarding process.

 The IPv6 network differs from the Ipv4 network in that the multicast protocol packets between the host and the router support the Multicast Listener Discovery (MLD) protocol. Compared with the IPv4 IGMP protocol, the MLD protocol is only in a different format. The negotiation process provided in the IGMP protocol and the MLD protocol is the same.

 The WiMAX system itself is a point-to-multipoint (PMP) system. The multicast function is also defined in the protocol. However, the multicast function is only implemented internally between the BS and the SS. The external multicast protocol cannot Use this feature directly.

 The implementation process of the IGMP snooping and the implementation process of the multicast service of the present invention will be described below with reference to FIG. The following description is made in conjunction with the IGMP V2 version of the IPv4 network.

 IGMP snooping implementation: First, the BS device needs to identify IGMP messages and then maintain the Layer 2 multicast address forwarding table based on the type of IGMP messages. The IGMP V2 version has three types of packets: IGMP query, IGMP report, and IGMP leave.

 a IGMP query: The IGMP query message is sent from the router and is used to confirm the multicast group member. The multicast group member should respond to the IGMP query message, that is, respond to the IGMP report message. The IGMP snooping module can determine the port of the Layer 2 device (BS device) connected to the router according to the IGMP query message, that is, the defined router port.

b. IGMP report: IGMP report messages are generated in two cases. One is the response to the router query; the other is the initiative to initiate to the router. Due to the two conditions The IGMP report packets are identical. Therefore, the IGMP snooping module cannot distinguish between the two cases by using IGMP report messages. The IGMP snooping module only needs to be based on the port that receives the IGMP report message and the group in the IGMP report message. Determine whether to add the port to the multicast group or create a multicast group forwarding table.

 c. IGMP leaving: When a group member wants to leave the multicast group, it can send an IGMP Leave message to the router. When the IGMP Snooping Module receives the IGMP Leave message, it passes the port that receives the IGMP Leave message. Send a specific group query message to confirm if the port still has other members of this multicast group.

 Corresponding to the Ipv4 network, there are also three types of messages in the IPv6 network: group membership query message, group membership report message, group membership reduction message; format of these three messages and reports in the IPv4 network The format of the text is different, but the message negotiation process is the same as the message negotiation process in the IPv4 network.

 The following describes the functions of multicast establishment, multicast addition, multicast leaving, and multicast deletion that can be implemented by the multicast service establishment module in conjunction with FIG. 5.

Multicast establishment: The BS device listens to the packet transmitted between the host and the router (step 500), and determines whether it is an IGMP report message (step 510). If yes, determines the multicast according to the multicast number in the packet. Group (step 520), and determining, according to the multicast address forwarding table in the device, whether the multicast group is a new multicast group (step 530); if yes, creating a multicast group forwarding table and in the multicast group The source SS device information is added to the forwarding table, a new CID is also assigned, and the egress in the newly created multicast group forwarding table is set to the CID (step 540). Then, the BS device further informs the source SS device by the protocol to receive the packet including the CID (step 550). „Multicast join: the BS device listens for the packet transmitted between the host and the router (step 500), and determines whether it is An IGMP report message (step 510), if yes, determining a multicast group according to the multicast number in the packet (step 520), and determining whether the multicast group is a new group according to the multicast address forwarding table in the device. Broadcast group (step 530), if not, only in the multicast address forwarding table The source SS device information is added to obtain an exit CID (step 545); thereafter, the BS device further notifies the source SS device by the protocol to receive the message including the CID (step 550).

 Multicast leaving: The BS device listens for the message transmitted between the host and the router (step 500). If it is not an IGMP report message (step 510), it determines whether it is an IGMP Leave message (step 515), if the BS If the packet received by the device is an IGMP Leave message, the device searches the multicast address forwarding table in the BS device according to the multicast group number in the IGMP Leave message, and deletes the source SS device information in the multicast address forwarding table. The exit CID information is obtained, and the source SS device is notified not to receive the message including the CID (step 525). Next, it is determined whether there is an SS device in the multicast address forwarding table (step 535), and if so, no processing is performed. If the packet of this multicast group is received from the network side, it is still sent through the CID.

 Multicast deletion: The BS device listens to the packet transmitted between the host and the router (step 500). If it is not an IGMP report message (step 510), it determines whether it is an IGMP Leave message (step 515), if the BS If the packet received by the device is an IGMP Leave message, the device searches the multicast address forwarding table in the BS device according to the multicast group number in the IGMP Leave message, and deletes the source SS device information in the multicast address forwarding table. The CID information is exported, and the source SS device is notified not to receive the CID message (step 525). Next, the BS device determines whether there is an SS device in the multicast address forwarding table (step 535), and if not, deletes the multicast address forwarding table and recovers the CID (step 560). If the subsequent BS device receives the packet of the multicast group from the network side, it discards it.

 Referring to FIG. 6, FIG. 6 is a flow chart of an IGMP proxy according to a preferred embodiment of the present invention. Figure 6 has many similarities to the IGMP snooping process disclosed in Figure 5. It also includes operations such as multicast setup, multicast join, multicast leave, and multicast delete.

The multicast establishment: the BS device intercepts the packet transmitted between the host and the router (step 600), and determines whether it is an IGMP report message (step 610); if yes, determines the group according to the multicast number in the packet. Broadcast group (step 620); and then forwarded according to the multicast address in the device Determining whether the multicast group is a new multicast group (step 630); if yes, creating a multicast group forwarding table and adding source SS device information in the multicast group forwarding table, and also assigning a new CID And setting the egress in the newly created multicast group forwarding table to the CID (step 640); then, the BS device sends the intercepted IGMP report message to the router (step 660), and further informs the source SS device to receive by the protocol. A message containing the CID (step 670).

 Multicast join: The BS device intercepts the packet transmitted between the host and the router (step 600), and determines whether it is an IGMP report message (step 610); if yes, determines the multicast group according to the multicast number in the packet. (Step 620); determining whether the multicast group is a new multicast group according to the multicast address forwarding table in the device (step 630); if not, only adding the source SS device information in the multicast address forwarding table, The exit CID is obtained (step 650); thereafter, the BS device further notifies the source SS device by the protocol to receive the message including the CID; (step 670).

 Multicast leaving: The BS device intercepts the packet transmitted between the host and the router (step 600). If it is not an IGMP report message (step 610), it determines whether it is an IGMP Leave message (step 615), if the BS device If the received packet is an IGMP Leave message, the multicast address forwarding table in the BS device is queried according to the multicast group number in the IGMP Leave message, and the source SS device information in the multicast address forwarding table is deleted. The CID information is sent, and the source SS device is notified that the message containing the CID is not received (step 625). Next, it is determined whether there is an SS device in the multicast address forwarding table (step 635), and if so, no processing is performed.

Multicast deletion: The BS device intercepts the packet transmitted between the host and the router (step 600). If it is not an IGMP report message (step 610), it determines whether it is an IGMP Leave message (step 615), if the BS device If the received packet is an IGMP Leave message, the multicast address forwarding table in the BS device is queried according to the multicast group number in the IGMP Leave message, and the source SS device information in the multicast address forwarding table is deleted. The CID information is sent, and the source SS device is notified not to receive the CID message (step 625). Afterwards, the BS device determines whether there is an SS device in the multicast address forwarding table (step 635), and if not, deletes the multicast address forwarding. The table is recycled and the CID is recovered (step 645). Then, the BS device sends an IGMP Leave message to the router (step 655); if the subsequent BS device receives the packet of the multicast group from the network side, the BS device discards.

 In addition, if the intercepted IGMP query message from the router (step 665), the BS device sends an IGMP response message to the router (step 675).

As can be seen from the above description, the BS device of the present invention uses the IGMP snooping module or the IGMP proxy module (for IPv4) to listen or intercept IGMP messages transmitted between the host and the router, and can be based on IGMP. The type of the packet maintains the multicast group forwarding table. Moreover, the BS device can perform the downlink multicast service according to the multicast group forwarding table.

 In fact, the key to implementing the multicast service is: The BS device allocates the same CID to all SSs in the multicast group (there is no special requirement for the CID), and the SS in the multicast group may not know the CID for the multicast chain. Road, only need to know: the data transmitted through the link corresponding to the CID needs MAC layer identification and processing. In this way, the multicast service for all the SSs in the multicast group can be implemented. Moreover, hosts that are not in the multicast group cannot receive multicast packets.

 It is apparent that the base station and method of the present invention effectively reduce SS power consumption and ensure communication security. In addition, the BS device is not required to perform complex replication and other multicast work, and the air interface bandwidth resource is also saved.

Claims

Claim  A base station in a broadband wireless access system, which is connected to a router and a subscriber station, wherein the base station comprises:  a packet obtaining module, configured to obtain a message between the user station and the router;  The multicast address forwarding table maintenance module is configured to maintain a multicast address forwarding table according to the type of the obtained packet;  The multicast service establishing module is configured to allocate a same connection identifier to all user stations in the multicast group, and manage the user stations in the multicast group according to the connection identifier and the maintained multicast address forwarding table.  The base station according to claim 1, wherein the packet obtaining module comprises a listening module and/or a proxy module;  The interception module is configured to listen to the message between the user station and the router;  A proxy module that intercepts packets between the subscriber station and the router.  3. The base station according to claim 2, wherein:  The listening module is an IGMP snooping module for IPv4 or an MLD snooping module for an IPv6 network;  The proxy module is an IGMP proxy module for IPv4 or an MLD proxy module for IPv6.  The base station according to claim 3, wherein the packets intercepted or intercepted by the IGMP snooping module and the IGMP proxy module include:  IGMP query messages from the router, IGMP report messages from the user station, and IGMP leave messages. The base station according to claim 4, wherein the IGMP snooping module and the IGMP proxy module are used to: Determining, when intercepting or intercepting the IGMP query message, a port of a base station device connected to the router;  When the IGMP report message is intercepted or intercepted, it is determined whether the port is added to the multicast group or the multicast group forwarding table is created according to the port that receives the IGMP report message and the group in the IGMP report message.  When the IGMP Leave message is intercepted or intercepted, the group query message is sent by the port that receives the IGMP Leave message.  The base station according to claim 3, wherein the MLD listening module and the MLD proxy module listen to or intercept the packet:  Group membership query message, group membership report message, and group membership reduction message message.  The base station according to any one of claims 1 to 6, characterized in that:  The group user station management performed by the multicast service establishing module is implemented by a multicast forwarding execution module connected to the multicast service establishing module.  8. A method for implementing a multicast service in a broadband wireless access system, the method comprising: Obtaining the packet transmitted between the user station and the router, and maintaining the multicast address forwarding table according to the type of the obtained packet; allocating the same connection identifier to all user stations in the multicast group, _s according to the connection identifier and the maintenance The multicast address forwarding table manages user stations in the multicast group.  The method according to claim 8, wherein the method for obtaining the message is: listening or intercepting a message between the user station and the router.  10. The method of claim 9 wherein: Performing the listening operation is: an IGMP snooping module for IPv4 or an MLD snooping module for an IPv6 network; The interception operation is performed: an IGMP proxy module for IPv4 or an MLD proxy module for IPv6.  11. The method of claim 9 wherein:  For an IPv4 network, the packet is an IGMP Query message, an IGMP report message, or an IGMP Leave message.  For an IPv6 network, the message is a group membership query message, a group membership report message, or a group membership reduction message message.  The method according to any one of claims 8 to 11, wherein the operation of managing the user station in the multicast group is multicast establishment, and the multicast establishment method includes: Obtain an IGMP report message transmitted between the user station and the router, and query the multicast address forwarding table according to the multicast number in the obtained IGMP report message. If the multicast group does not exist, create a new multicast group. Publish and add the source subscriber station equipment information in the multicast group forwarding table, also allocate a new connection identifier and set the exit in the newly created multicast group forwarding table as the connection identifier; and notify the source user station device to receive the The connection identifier is ^ ¹艮.  The method according to any one of claims 8 to 11, wherein the operation of the user station in the management multicast group is a multicast join, and the multicast join method includes:  Obtain an IGMP report message transmitted between the user station and the router, and query whether the multicast group exists in the multicast address forwarding table according to the multicast number in the obtained IGMP report message. If yes, the multicast address is forwarded. The source user station device information is added in the publication to obtain the egress connection identifier; the source user station device is also notified to receive the message including the connection identifier.  The method according to any one of claims 8 to 11, wherein the operation of the user station in the management multicast group is multicast leaving, and the multicast leaving method includes: Obtain the IGMP Leave message sent between the user station and the router, query the multicast address forwarding table according to the multicast group number in the IGMP Leave message, and delete the source user station device information in the multicast address forwarding table. Export connection identification information; also notify the source subscriber station equipment not Receiving a message including the connection identifier;  Determining whether there is a subscriber station device in the multicast address forwarding table, if not, not processing; and receiving the packet from the multicast group when receiving the packet of the multicast group from the network side, The text is sent out.  The method according to any one of claims 8 to 11, wherein the operation of managing the user station in the multicast group is multicast deletion, and the method for deleting the multicast includes:  Obtain the IGMP Leave message sent between the user station and the router, query the multicast address forwarding table according to the multicast group number in the IGMP Leave message, delete the source user station device information in the multicast address forwarding table, and obtain the exit. Connecting the identification information; and notifying the source user station device that the packet containing the connection identifier is not received;  Determining whether there is a user station device in the multicast address forwarding table, if not, deleting the multicast address forwarding table, and retrieving the connection identifier; and when receiving the packet of the multicast group from the network side, discarding the Received message.