WO2008061417A1

WO2008061417A1 - Multicast control processing method, system and broadband access device

Info

Publication number: WO2008061417A1
Application number: PCT/CN2007/002227
Authority: WO
Inventors: Wumao Chen
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-11-21
Filing date: 2007-07-23
Publication date: 2008-05-29
Also published as: CN101193017A; CN101193017B

Abstract

A multicast control processing method, system and broadband access device, when the broadband access device does not have the load or its load is below a first threshold, the broadband access device establishes a member list for a multicast group that has no member list preliminarily, and requests a multicast router for the multicast stream of the multicast group and obtains it; when a user terminal requests the broadband access device to join in the multicast group, the broadband access device adds the user information corresponding to the user terminal into the pre-established member list of the multicast group, and sends the pre-requestedand obtained multicast stream of the multicast group to the user terminal.

Description

Multicast control processing method, system and broadband access device

Technical field

The present invention relates to the field of network communication technologies, and in particular, to a multicast control processing method, system, and broadband access device. Background technique

With the development of video multicast services, video multicast services are becoming more and more important for operators. Whether you want to become a true full-service operator, seize the high-yield cable TV market, or just want to develop Attractive broadband value-added services to attract more users to use the broadband network, to solve the problem of broadband bearer video services is a top priority. The operator will use broadband access equipment, such as Digital Subscriber Line Access Mulitiplexer (DSLAM), as a broadband bearer network for video data, and provide hundreds of groups by signing with multiple TV program providers. The broadcast channel requires the broadband access device as the device of the last access user, and implements corresponding features such as controllable multicast, large-capacity multicast forwarding entries, and fast channel switching.

Taking the broadband access device DSLAM as an example, in the video multicast service implemented by the broadband access device, the process in which the user terminal joins the multicast group corresponding to the specified channel is as shown in FIG. 1 , and the following steps are included:

In step S101, the user specifies the channel that needs to be viewed, and the user terminal sends an IGMP (Internet Group Management Protocol) Join message to the DSLAM, where the message carries the information of the multicast group corresponding to the designated channel. ;

To prevent packet loss, the user terminal usually sends two IGMP Join messages to the DSLAM. Step S102, the DSLAM, as an IGMP Proxy, determines whether the user who sends the IGMP Jom message can join the multicast group corresponding to the designated channel after receiving the IGMP Join message. If yes, go to step S103; otherwise, directly End.

When the user who sends the IGMP Jom message can join the multicast group corresponding to the specified channel, the content of the judgment may be whether the user has the right to join the multicast group and/or whether the user port has sufficient bandwidth support. Step S103, the DSLAM determines whether the multicast group already has a member table, and if so, proceeds to step S107, otherwise proceeds to step S104;

Step S104, the DSLAM sends an IGMP Join message to the multicast router of the upper layer to request the multicast stream of the multicast group, and creates a member table for the multicast group, and adds the information of the user to the member table. Step S105: After receiving the IGMP Join message from the DSLAM, the multicast router sends the multicast stream of the multicast group requested by the DSLAM to the DSLAM;

Depending on the network and the user access, the multicast router may exchange multicast routing information with its upper-layer device through Protocol Independent Multicast (PIM)/IGMP.

Step S106: The DSLAM receives the multicast stream, and sends the multicast stream to the user port according to the information of the user in the multicast group member table, and ends.

Step S107, the DSLAM determines whether the user's information exists in the member table of the multicast group, and if yes, does not process, and ends, otherwise, proceeds to step S108;

Step S108: The DSLAM adds the information of the user to the member table of the multicast group.

The DSLAM sends the multicast stream of the multicast group to the user port according to the information of the user in the multicast group member table. Therefore, after the DSLAM adds the user information to the member table of the multicast group in this step, the DSLAM The multicast stream of the multicast group will be sent to the port of the user.

Since there may be multiple user terminals under one user port, there may be one of the user terminals that has sent a request to the DSLAM for the same channel, and the DSLAM has added the user information to the member table of the multicast group. If the user port sends the multicast stream of the multicast group corresponding to the channel, another user terminal under the port also needs to watch the channel and send a request to the DSLAM again. At this time, the DSLAM does not need to be in the multicast. The user's information is added again in the member table of the group, so it can be processed without any reason. If it is the first user terminal under the user port to request the multicast stream of the multicast group from the DSLAM, the DSLAM needs to be in the Add the user's information to the member table of the multicast group.

In the video multicast service implemented by the broadband access device, the process in which the user terminal leaves the multicast group corresponding to the specified channel is as shown in FIG. 2, and includes the following steps:

Step S201: When the user switches channels or stops watching, the user terminal sends IGMP to the DSLAM. The Leave message carries the information of the multicast group corresponding to the channel that the user specifies to leave. Step S202: After receiving the IGMP Leave message, the DSLAM sends a specific group query message to determine whether there is another port under the port where the user terminal is located. The terminal is watching the channel, and if so, directly ends; otherwise, proceeding to step S203;

Since there may be multiple user terminals under one user port, there may be a case where one terminal wants to leave the multicast group corresponding to the specified channel, and the other terminal continues to watch the channel. Therefore, in this step, The DSLAM sends a specific group query message to determine if there are other terminals under the port where the user terminal is located.

After receiving the specific group query message, the user terminal sends a response to the DSLAM if it is watching the channel, otherwise it does not respond to the specific group query message. After receiving the specific group query message, if the DSLAM receives the response from the user terminal within the set time, it considers that other terminals are watching the channel under the port, otherwise, it is considered that no other terminal is watching the channel under the port. .

Step S203, the DSLAM stops sending the multicast stream of the multicast group to the port where the user terminal is located; Step S204, the DSLAM determines whether the user is the last member of the multicast group, and if yes, proceeds to step S205, otherwise, proceeds to step S207. ;

In a specific implementation, the DSLAM may determine whether the user is the last member of the multicast group according to whether the information of the user is the last user information recorded in the member table of the multicast group.

In specific implementation, step S203 and step S204 do not have a certain order.

Step S205: The DSLAM sends an IGMP carrying the multicast group information to the upper multicast router.

Leave the message, and delete the member table of the multicast group;

Step S206: After receiving the IGMP Leave message, the multicast router stops sending the multicast stream of the multicast group to the DSLAM, and ends.

Step S207: The DSLAM deletes the information of the user in the member table of the multicast group.

If the user terminal sends an IGMP Quick Leave to the DSLAM, the DSLAM does not send the specific group query, but directly stops sending the multicast stream of the multicast group to the port where the user terminal is located, and determines whether the user has the multicast group. The last member, for subsequent processing.

The user terminal sends an IGMP Leave message to the DSLAM to leave the multicast group. The DSLAM also sends an inquiry message to the port of the user terminal in the locally stored multicast group member table. If the DSLAM does not receive the response to the query message after waiting for the set query interval, the DSLAM considers the multicast group. If there is no member, the upper-layer multicast router sends an IGMP Leave message carrying the multicast group information and deletes the member table of the multicast group. The DSLAM can send query messages to the ports of the user terminals in the multiple member tables that it saves at the same time, or send them separately.

The inventor has found that in the prior art, the member table of the multicast group is created when the first user joins the multicast group, and when there is no member in the multicast group, the member table Will be deleted.

When the video multicast service is used, such a scenario often occurs:

During a great program, such as a sports game or a popular movie, a large number of users or even all users focus on a certain channel; accordingly, only a few multicast groups have members in the DSLAM for a certain period of time, and IGMP is received. The number of messages is also small, and the load of IGMP processing is very light. When the program ends, all or part of the user immediately switches to any other channel. Accordingly, the DSLAM will receive a large number of IGMP messages, and the IGMP processing load will be very heavy. It can be seen that the load of the DSLAM is uneven, and there may be an instantaneous processing performance bottleneck. Summary of the invention

The present invention provides a multicast control processing method, system, and broadband access device, which are used to reduce the possibility of a transient processing performance bottleneck of a broadband access device.

The present invention provides a multicast control processing method, which includes the following steps:

When the broadband access device is not loaded or its load is lower than the first threshold, the broadband access device creates a member table for the multicast group without the member table in advance, and requests and obtains the multicast of the multicast group from the multicast router. Flow

When the user terminal is required to join the multicast group to the broadband access device, the broadband access device adds the user information corresponding to the user terminal to the member table of the multicast group that is created in advance, and provides the user information to the user. The terminal sends the multicast stream of the multicast group obtained in advance.

The present invention also provides a multicast control processing system, including a broadband access device and a multicast router, where: The broadband access device is configured to create a member table for a multicast group without a member table in advance, and request the multicast group from the multicast router when the load is not loaded or the load is lower than the first threshold. a multicast stream, and when receiving a request for joining the multicast group sent by the user terminal, adding information of the user corresponding to the user terminal to the member table of the multicast group that is created in advance, to the user terminal Sending a multicast stream of the multicast group obtained in advance;

The multicast router is configured to send the multicast stream to the broadband access device according to the request of the broadband access device.

The present invention also provides a broadband access device, including a storage module, a first processing module, a multicast module, and a second processing module, where:

The storage module is configured to save a member table of the multicast group;

The second processing module is configured to create a member table in the storage module and send a request in advance for the multicast group without the member table when the broadband access device is not loaded or the load is lower than the first threshold. The multicast stream message of the multicast group outputs the multicast stream to the multicast module after obtaining the multicast stream;

The first processing module is configured to: after receiving the message that the user terminal requests to join the multicast group, add the user corresponding to the user terminal to the member table of the multicast group that is pre-created in the storage module. Information

The multicast module is configured to send, to the user equipment, the multicast stream of the multicast group that is requested in advance according to the information of the user in the member table of the multicast group.

In the present invention, when the broadband access device is not loaded or its load is lower than the first threshold, the broadband access device creates a member table for the multicast group without the member table in advance, and requests and obtains the multicast from the multicast router. a multicast stream of the group; when the user terminal requests the broadband access device to join the multicast group, the broadband access device adds the information of the user corresponding to the user terminal to the user terminal in the member table of the multicast group that is created in advance. Sending the pre-requested multicast stream of the multicast group, and the broadband access device does not need to obtain the request to join the multicast group sent by the user terminal, and then creates a member table of the multicast group and requests the multicast router. And obtaining the multicast stream of the multicast group, which reduces the processing load of the broadband access device when processing the request of the user terminal to join the multicast group without the member table, and reduces the request for joining a large number of users. Broadband access devices in the multicast table of the member table have the possibility of instantaneously handling performance bottlenecks. Since the technical solution of the present invention increases the processing load of the broadband access device only when the broadband access device is in a no-load or low-load state, the load of the broadband access device is balanced, and the transient processing performance bottleneck of the broadband access device is reduced. The possibility. DRAWINGS

1 is a flow chart of a user group joining a multicast group corresponding to a specified channel in the prior art; FIG. 2 is a flow chart of a user group leaving a multicast group corresponding to a designated channel in the prior art; A flowchart of processing performed when the DSLAM is in a no-load or low-load state in the first embodiment of the invention;

4 is a flowchart of processing after a DSLAM receives an IGMP Join message sent by a user terminal according to Embodiment 1 of the present invention;

5 is a flowchart of processing performed when the DSLAM is in a no-load or low-load state according to the second embodiment of the present invention;

6 is a block diagram of a multicast control processing system in an embodiment of the present invention;

Figure Ί is a block diagram of a broadband access device in one embodiment of the present invention. detailed description

In the present invention, when the broadband access device is not loaded or its load is lower than the first threshold, the broadband access device creates a member table for the multicast group without the member table in advance, and requests and obtains the multicast group from the multicast router. When the user terminal requests the broadband access device to join the multicast group, the broadband access device adds the user information corresponding to the user terminal to the member table of the multicast group that is created in advance, and sends the user information to the user. The terminal sends the multicast stream of the multicast group obtained in advance. Thereby, the load of the broadband access device is balanced, and the possibility of instantaneous processing performance bottleneck of the broadband access device is reduced.

The invention will now be further described with reference to the drawings and embodiments.

Embodiment 1

In order to alleviate the processing load of the broadband access device (taking the DSLAM as an example) when processing the request of the user terminal to join the multicast group without the member table, and balancing the load of the DSLAM, the P is low and the DSLAM appears. The possibility of processing the performance bottleneck in an instant, in this embodiment, when the DSLAM is in a no-load or low-load state, the process shown in FIG. 3 is performed, including the following steps:

Step S301, the DSLAM determines whether all the multicast groups have a member table, and if so, directly ends, otherwise, proceed to step S302;

Step S302: The DSLAM selects a multicast group that does not have a member table, creates a member table for the multicast group, and sends an IGMP Join message to the upper-layer multicast router to request the multicast stream of the multicast group.

In a specific implementation, the DSLAM can select a multicast group without a member table according to the setting rule. For example, the priority of the member table is determined according to the rating of each channel, or the administrator sets the priority through the command line or the network management interface. Level, set some of the most popular channels (such as live sports events, etc.) to high priority.

The DSLAM can also create a member table for multiple multicast groups without member tables, and send IGMP Join messages to the multicast routers to request multicast streams of each multicast group.

Step S303: The multicast router sends the multicast stream of the multicast group to the DSLAM.

In this embodiment, the DSLAM can determine whether it is in a no-load state by judging whether there is currently a task to be processed; when there is no task currently to be processed, the DSLAM considers that it is in a no-load state, otherwise the DSLAM considers that it is under load. status.

The DSLAM can also set the period and count the processing load in the period. If the processing load in the period is lower than the first threshold, it is considered to be in a low load state, otherwise it is considered to be in a non-low load state. The first threshold can be set according to specific needs.

The processing flow of the DSLAM after receiving the IGMP Join message sent by the user terminal is as shown in FIG. 4, and includes the following steps:

Step S401: Determine whether the user who sends the IGMP Join message can join the multicast group corresponding to the designated channel, and if yes, go to step S402, otherwise, directly end.

Step S402, determining whether the multicast group already has a member table, and if yes, proceeding to step S405, otherwise proceeding to step S403;

Step S403, the uplink multicast router sends an IGMP Join message to request the multicast stream of the multicast group. Step S404, creating a member table for the multicast group, proceeding to step S406;

Step S405, determining whether there is information about the user corresponding to the user terminal in the member table of the multicast group, and if yes, processing is not completed, otherwise, proceeding to step S406;

Step S406, adding information of the user to the multicast group member table.

In the above process, the step S403 and the step S404 do not have a certain sequence relationship. After the DSLAM receives the multicast stream of the multicast group, the multicast stream is sent to each user in the multicast group member table.

It can be seen that when the user terminal sends an IGMP Join message to the DSLAM to request to join a multicast group without a member table, the DSLAM needs to perform steps of steps S401, S402, S403, S404, and S406, and if the DSLAM has passed the figure. The process shown in Figure 3 creates a member table for a multicast group without a member table, and requests and obtains the multicast stream of the multicast group from the upper multicast router. Therefore, when the user terminal sends an IGMP Join message request to the DSLAM. When joining the multicast group, the steps that the DSLAM needs to perform are steps S401, S402, S405, and S406, and there are only four steps. Moreover, S401, S402, and S406 are steps that need to be performed in both cases, and the processing load brought to the DSLAM in step S405 is small. Since the DSLAM has no members in the member table created for the multicast group, in this case, the steps that the DSLAM needs to perform must include step S406.

The technical solution of the embodiment is used to increase the processing load of the DSLAM when the DSLAM is in a no-load or low-load state, and to reduce the DSLAM's relatively heavy load when processing the request of the user terminal to join the multicast group without the member table. The processing load of the smooth DSLAM processing load from the DSLAM can effectively alleviate the DSLAM load when a large number of users send IGMP Join messages to the DSLAM, and reduce the bandwidth access device when a large number of users request to join a multicast group without a member table. There is a possibility of dealing with performance bottlenecks in an instant.

For example, a DSLAM provides video services to 255 users, providing a total of 256 channels. It is assumed that each step in the processing flow of the DSLAM after receiving the IGMP Join message sent by the user terminal requires lms (milliseconds) respectively. When there is a wonderful program, all users select the same channel; when the program ends, the 255 users switch to the other 255 channels in 1.1s (seconds) respectively. If you use the existing technology method and do not create a member table for a multicast group without a member table in advance, each user needs 5 steps for 5ms. The DSLAM needs to process the IGMP Join message of all users. 255*5=1275ms > 1.1s, the system has an instantaneous processing performance bottleneck; if the technical solution of this embodiment is adopted, it is assumed that the DSLAM has created a member table for the 255 channels during the highlight program, so each user only needs In the 4 steps, each user only needs 4 steps for 4ms. After processing the IGMP Join messages of these users, 255 *4=1020ms < 1.1s is required, and the system does not have an instantaneous performance bottleneck.

In this embodiment, when the DSLAM creates a member table for a multicast group without a member table, the result may be that the member table exists in all channels. Therefore, when the last member of the member table of a multicast group leaves the multicast group, The member table can be reserved, and the IGMP Leave message carrying the multicast group information is not sent to the multicast router at the upper layer, thereby further reducing the processing load of the DSLAM. Or, according to the setting rule, whether to delete the member table without members, for example, when the last member of the member table of a multicast group leaves the multicast group, determine whether the rating of the multicast group is higher than necessary. The third threshold is set. If yes, the member table is reserved, and the multicast router that does not send the multicast group information is sent to the multicast router in the upper layer. Otherwise, the member table is deleted, and the multicast router is sent to the upper layer. IGMP Leave message of multicast group information.

Embodiment 2

It is easy to imagine that if a member table is created for all channels, and an IGMP Join message is sent to the upper layer multicast router for all channels to request its multicast stream, the DSLAM can reduce the processing load regardless of which channel the multicast stream is requested by the user. It can minimize the possibility that the DSLAM will encounter transient processing performance bottlenecks. However, if some channels do not need to be viewed by users for a long time, the upper-layer multicast routers always send multicast streams of these channels to the DSLAM, which may cause waste of resources. And, in consideration of the specific implementation, the bandwidth between the DSLAM and the upper-layer multicast router is limited. Therefore, in a specific implementation, the DSLAM can create a member table for the multicast group without the member table according to the setting rule, and The layer multicast router requests the multicast stream corresponding to the multicast group.

In this embodiment, the broadband access device (for example, the DSLAM) determines whether to process the multicast group without the member table according to the rating when the user is in the no-load or low-load state. The specific process is shown in FIG. 5. As shown, the following steps are included:

Step S501, the DSLAM determines whether each multicast group whose audience rating is higher than the second threshold has a member table, and if so, directly ends, otherwise, proceed to step S502; The second threshold can be set according to requirements, and the bandwidth between the DSLAM and the multicast router and the load that the DSLAM can bear can be considered in the specific setting.

Step S502, the DSLAM selects a multicast group whose audience rating is higher than the second threshold and has no member table, creates a member table for the multicast group, and sends an IGMP Join message to the upper multicast router to request the multicast stream of the multicast group. ;

The DSLAM can also create a member table for multiple multicast groups with a higher audience rating than the second threshold and no member table, and send an IGMP Join message to the upper multicast router to request the multicast stream of each multicast group.

Step S503: The multicast router sends the multicast stream of the multicast group to the DSLAM.

In the specific implementation, the DSLAM can also process multicast groups without member tables according to the administrator's designation.

In this embodiment, the result that the DSLAM creates a member table for a multicast group whose audience rating is higher than the second threshold and has no member table may be that the members whose all ratings are higher than the second threshold have a member table, therefore, when If the last member of the member group of the multicast group leaves the multicast group, the system can determine whether the audience rating of the multicast group is higher than the second threshold. If yes, the member table is retained. The IGMP Leave message carrying the multicast group information is sent to further reduce the processing load of the DSLAM. Otherwise, the member table is deleted, and the IGMP Leave message carrying the multicast group information is sent to the upper multicast router. In a specific implementation, the rule for deciding whether to retain the member table may be whether the rating of the multicast group is higher than a third threshold set as needed.

Similarly, according to the rating, in the specific implementation, the DSLAM can also create a member table only for the multicast group whose rating is within the set number of bits and has no member table, and request and obtain the set number of bits from the multicast router. Multicast group multicast stream. For example, if the number of digits in the rating ranking is 40th, the DSLAM will judge whether the multicast group with the audience rating of 40 has members in the no-load or low-load state. Table, if yes, no processing; otherwise, create a member table for a multicast group with a rating of 40 and no member table, and request and obtain a group of multicast groups within the set number of bits from the multicast router. Broadcast.

The multicast control processing system in one embodiment of the present invention, as shown in FIG. 6, includes a user terminal 100, a broadband access device 200, and a multicast router 300, where:

When the broadband access device 200 is under no load or its load is lower than the first threshold, a member table is created in advance for the multicast group without the member table, and the multicast router 300 is requested to obtain the multicast stream of the multicast group; When the terminal 100 requests the broadband access device 200 to join the multicast group, the broadband access device 200 adds the information of the user corresponding to the user terminal 100 to the member table of the pre-created multicast group, and sends the pre-requested information to the user terminal 100. The multicast stream of the multicast group.

The broadband access device 200 in one embodiment of the present invention, as shown in FIG. 7, includes a storage module 201, a first processing module 202, a second processing module 203, and a multicast module 204, where:

The storage module 201 stores a member table of the multicast group;

When the broadband access device 200 has no load or its load is lower than the first threshold, the second processing module 203 creates a member table in the storage module 201 for the multicast group without the member table in advance, and sends a group requesting the multicast group. The broadcasted message is output to the multicast module 204 after the multicast stream is obtained;

The second processing module 203 includes a determining unit and a processing unit, where:

The determining unit determines whether the broadband access device 200 has no load or determines whether the load of the broadband access device 200 is lower than a first threshold. If yes, the processing unit performs processing, otherwise the processing is not performed; the processing unit is a group without a member table in advance. The multicast group creates a member table in the storage module 201, and requests the multicast stream of the multicast group from the multicast router 300, and outputs the multicast stream to the multicast module 204 after obtaining the multicast stream.

After receiving the message that the user terminal 100 requests to join the multicast group, the first processing module 202 adds the information of the user to the member table of the multicast group that is pre-created in the storage module 201;

The multicast module 204 transmits the multicast stream of the multicast group obtained in advance to the user terminal 100 according to the information of the user in the member table of the multicast group.

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention are claimed in the present invention The invention is also intended to cover such modifications and variations within the scope and equivalents thereof.

Claims

Rights request

A multicast control processing method, comprising the steps of:

When the user terminal requests the broadband access device to join the multicast group, the broadband access device adds the user information corresponding to the user terminal to the member table of the multicast group that is created in advance, and sends the user information to the user terminal. Sending the multicast stream of the multicast group obtained in advance.

2. The method according to claim 1, wherein when the broadband access device is unloaded or its load is lower than the first threshold, the broadband access device is pre-emptively higher than the second threshold and has no member table. The multicast group creates a member table, and requests and obtains a multicast stream from the multicast router that has a multicast group whose audience rating is higher than the second threshold and has no member table.

3. The method according to claim 1, wherein when the broadband access device is unloaded or its load is lower than the first threshold, the broadband access device is pre-positioned for the audience rating within the set number of bits and has no members. The multicast group of the table creates a member table, and requests the multicast router to obtain the multicast stream of the multicast group whose rating is within the set number of bits and has no member table.

The method according to claim 1, wherein when the last member leaves the multicast group whose audience rating is higher than the third threshold, the broadband access device reserves the multicast with the audience rating higher than the third threshold. The member table of the group.

The method according to claim 1, wherein the broadband access device determines the priority of the multicast group without the member table according to the rating, and according to the priority, the multicast has no member table. The group creates a member table, requests and obtains a multicast stream of each multicast group without the member table from the multicast router.

The method of claim 1, wherein the administrator sets the priority of the multicast group without the member table through a command line or a network management interface, and the broadband access device has no members according to the priority. The multicast group of the table creates a member table, requests and obtains the multicast stream of each multicast group without the member table from the multicast router.

A multicast control processing system, comprising a broadband access device and a multicast router, wherein the broadband access device is configured to have no member in advance when no load or its load is lower than a first threshold The multicast group of the table creates a member table, and requests and obtains the multicast stream of the multicast group from the multicast router, and is pre-created when receiving the request for joining the multicast group sent by the user terminal. Adding information of the user corresponding to the user terminal to the member table of the multicast group, and transmitting, to the user terminal, the multicast stream of the multicast group that is requested in advance;

The system of claim 7, wherein the broadband access device comprises a storage module, a first processing module, a multicast module, and a second processing module, where:

The storage module is configured to save a member table of the multicast group;

9. The system of claim 8, wherein the second processing module comprises a determination unit and a processing unit, wherein:

The determining unit is configured to determine whether the broadband access device has no load or determine whether the load of the broadband access device is lower than a first threshold, and if yes, notify the processing unit to perform processing, otherwise, no processing is performed;

The processing unit is configured to create a member table in the storage module for a multicast group without a member table, and request a multicast stream of the multicast group from the multicast router, where the multicast is obtained. After the flow The multicast stream is output to the multicast module.

A broadband access device, comprising: a storage module, a first processing module, a multicast module, and a second processing module, wherein:

The storage module is configured to save a member table of the multicast group;

The broadband access device according to claim 10, wherein the second processing module comprises a determining unit and a processing unit, wherein:

The processing unit is configured to create a member table in the storage module for a multicast group without a member table, and request a multicast stream of the multicast group from the multicast router, where the multicast is obtained. The multicast stream is output to the multicast module after the stream.