WO2009024054A1

WO2009024054A1 - A method, device and system for realizing the management protocol agent for members in a multicast group

Info

Publication number: WO2009024054A1
Application number: PCT/CN2008/071941
Authority: WO
Inventors: Ning Zhu
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-08-15
Filing date: 2008-08-11
Publication date: 2009-02-26
Also published as: CN101369994A

Abstract

A method for realizing the management protocol agent for members in a multicast group is provided. In the method an upstream interface and at least one downstream interface are set on the media gateway MG, the media gateway controller MGC maintains the multicast group member database which synthesizes the subscription status of each of the members in the multicast group of the downstream interface, MG receives the report message for joining the multicast group or the message for leaving the multicast group from the downstream network via the downstream interface, reports upwards to MGC; MGC updates the content in the multicast group member database according to the report message or the message for leaving the multicast group; MGC determines whether the multicast group member database is changed, if so, instructs MG to send the report message or the message for leaving the multicast group to the upstream network via the upstream interface. Another method for realizing the management protocol agent for members in a multicast group, and a system, device for realizing the management protocol agent for members in a multicast group are disclosed. The solution of the present invention could make MG have the function of the management protocol agent for members in a multicast group.

Description

Method, device and system for realizing multicast group member management protocol agent

Technical field

The present invention relates to the field of multicast technologies, and in particular, to a method, device and system for implementing a multicast group member management protocol proxy.

Background technique

IP multicast (multicast) refers to the transmission of data packets to a certain subset of nodes in the network in an IP network. This subset is called a multicast group (mul t icas t group ). ₀ The basic idea of IP multicast is that the source host sends only one data. The destination address in this data is the multicast group address. All destination hosts in the multicast group can receive the same data copy, and multicast. Hosts other than the group cannot receive it. The multicast group is identified by a class D IP address (224. 0. 0. 0 ~ 239. 255. 255. 255 ).

According to the scope of the protocol, the multicast protocol is divided into a host-router protocol, that is, a multicast member management protocol; and a router-router protocol, mainly various multicast routing protocols. The multicast group member management protocol includes Internet Group Management Protocol (IGMP) and multicast listener discovery (Mul t icas t Li s tener Di scovery, MLD); the multicast routing protocol is further divided into intra-domain multicast routing protocols and domains. There are two types of inter-multicast routing protocols.

The multicast group member management protocol is used to establish the multicast group membership information in the IP subnet (subnet) where the interface is located in the router. The information is specifically each multicast group, or further fine-grained. To filter the multicast source address, whether there is an active member in the IP subnet. Based on the membership information of these multicast groups, the intra-domain multicast routing protocol uses a certain multicast routing algorithm to construct a multicast distribution tree, establishes a multicast routing state in the router, and the router performs multicast packet forwarding according to these states. The inter-domain multicast routing protocol is based on the inter-domain multicast routing policy configured in the network.

(Autonomous System, AS) releases multicast routing information and multicast source information, so that multicast data can be forwarded between domains. The IGMP protocol is used for group member management of the IPV4 network, and the IPM6 network uses a protocol MLD similar in function and content to IGMP. The following takes IGMP as an example to multicast groups. The member management agreement is further introduced.

The IGMP protocol runs between the host and the multicast router directly connected to the host. The IGMP function is bidirectional: On the one hand, through the IGMP protocol, the host notifies the multicast router that it wants to join and receive information about a specific multicast group. On the other hand, the multicast router periodically queries whether a member of a known multicast group in the local area network is active through the IGMP protocol, that is, whether the network segment still belongs to a member of a multicast group and implements the connected network. Collection and maintenance of group membership. Through IGMP, the information recorded in the router is whether a multicast group has a group member locally, rather than a correspondence between the multicast group and the host.

So far, IGMP has three versions. The basic group member query and reporting process is defined in IGMPvl (RFC1112); IGMPv2 is defined by RFC2236, which adds a mechanism for group members to leave quickly on the basis of IGMPvl; the main function added in IGMPv3 (RFC3376) is that members can specify receiving or Specifies to not receive packets from certain multicast sources, that is, to filter the multicast source address. The following focuses on the principles of the IGMPv2 protocol.

When there are multiple multicast routers in the same network segment, IGMPv2 elects a unique querier through the querier election mechanism. The querier periodically sends a general group query message for membership relationship query; the host sends a report message to respond to the query. The time when the host sends a report message is random. When other members in the same network segment are detected to send the same message, the response message is suppressed. If a new host wants to join the multicast group, it does not have to wait for the querier to query the message, but actively sends a report message. When leaving the multicast group, the host sends a leave group message; after receiving the leave group message, the querier sends a specific group query message to determine if all group members have left. For a router that is a member of a group, it behaves like a normal host, responding to queries from other routers. Through the above mechanism, a table is established in the multicast router, which records which group members are on the subnet corresponding to each interface of the router. After receiving a data packet from a multicast group, the router forwards data packets only to the interface of the multicast group member. The host joins the multicast group and must periodically send a report message to maintain its status. The multicast router starts the group membership interval timer. If the host does not receive the report message that the host maintains the status before the timer expires, the member of the group in the subnet is deleted. Department. There are other multicast timers, for example: Query Interva l timer, which sends a general query message when the timer expires. The last member query interval (La st Member Query Interva l) timer, after receiving the message of the leaving group sent by the host, the querier sends a specific group query message to determine whether all group members have left, and starts the timer. Resend each timeout, the number of times sent is determined by the last member query count as t Member Query Count). If the timer of the last query has not received the report message of the group member of the left group, the child is deleted. The membership of the group of the network. In addition, as the host, an Unso Detected Interval Timer is also required to control the time when the host repeatedly sends the active message, and the Query Response Interva timer is used to control The time the host responded to the query message.

Multicast routes can be divided into two categories: source tree and shared tree. ₀ The source tree is the shortest path from the multicast source to each receiver. A forwarding tree that is combined to form. Since the source tree uses the shortest path from the multicast source to the receiver, it is also called the shortest path tree (SPT). For a multicast group, the network establishes a tree for any multicast source that sends packets to the group. The shared tree uses a router as the root of the routing tree. This router is called a Rendezvous Point (RP) and combines the shortest path of the RP to all receivers to form a forwarding tree. When using a shared tree, there is only one tree in the network for a certain group. All multicast sources and receivers use this tree to send and receive packets. The multicast source sends data packets to the root of the tree, and then the packets are forwarded down to all receivers. In multicast, a message is sent to a group of recipients, which are identified by a logical address. After receiving the packet, the router must determine the upstream (pointing to the multicast source) and the downstream direction according to the source and destination addresses, and forward the "3⁄4 text" away from the multicast source. This process is called reverse path forwarding. Reverse Pa th Forward ing , RPF ).

The multicast routing protocol is more complicated than the multicast group member management protocol, so the requirements on the device are relatively high. In the RFC4605, the multicast group member management protocol proxy technology is introduced, which is specifically the IGMP/MLD proxy technology. When the network topology is relatively simple, the multicast routing protocol does not need to be run, but the multicast-based multicast is introduced. The proxy device of the group member management protocol replicates and forwards the multicast data stream. That is, the proxy device learns the multicast group member information through the proxy multicast group member management protocol message, and implements the multicast data stream forwarding according to the multicast group member information. By using the multicast group member management protocol proxy technology, the cost of the device can be saved first, and the deployment speed can be accelerated. When the proxy device is deployed between the core network and the access network, the proxy device does not need to support the multicast routing of the core network. The protocol, and only need to send multicast group member management protocol messages to it, thus enhancing the versatility of the proxy device.

The principle of the implementation of the IGMP/MLD proxy is as follows: The host interface of the proxy device, also known as the upstream spoofing interface, points to the direction of the root node of the shared tree or the source tree. On this interface, run the IGMP host function. Maintain the multicast group member database (Membership Database) on the proxy device. The record in the database is the multicast group member information of each downstream flow interface.

The merge of (membershi informa t ion) (merge, or summary), can also be said to be the merge of the subscr ipt of the multicast group of each downstream stream interface. The merge rule is shown in RFC4605, and each record format is (multicast group address, filter condition, multicast source address list). The member database is equivalent to the record sum of the status of the multicast group members of the proxy device as a host on the IP subnet where the upstream flow interface resides. When the IGMP query packet is received on the upstream flow interface, the proxy device sends an IGMP member report to the host port after querying the member database. When the member database changes, the active device sends the multicast or the multicast packet to the connected router. The IGMP/MLD agent also records the multicast subscription status on each downstream flow interface. The host interface receives the multicast data flow that matches the member database record, and then forwards the multicast packet according to the multicast group member status on each downstream flow interface. . The router interface of the proxy device, also known as the downstream traam interface, deviates from the node and connects to the host. The proxy device runs the IGMP router function on this port to perform the group member login query deletion of the users in the connected IP subnet. Implementing the receiving member report message and leaving the multicast group request; sending the query packet; forwarding the received multicast data packet to the downstream flow interface of the multicast group member having the multicast data stream.

The IGMP/MLD proxy must also be elected as a querier in the subnet where the downstream flow interface resides, so that it can become the only device in the subnet that forwards the multicast data stream.

The Media Gateway Controller (MGC) and the Media Gateway (MG) are two key components in the packet network. The network architecture consisting of MGC and MG is shown in Figure 1. MGC is responsible for call control functions, MG is responsible for business Load function, the MG interacts through the Real-Time Transport Protocol (RTP). The gateway control protocol is the main protocol for communication between the MG and the MGC. Currently, the H.248/MeGaCo and the Media Gateway Control Protocol (MGCP) are widely used.

In H. 248 protocol as an example, various resources on the MG are abstracted as a terminal (Termina t ion) ₀ terminal is divided into physical (Phys i ca l) and a temporary terminal (Ephemera l) terminal, the former represent some semi-permanent Existing physical entities, such as TDM channels, etc., which represent common resources released after temporary applications, such as RTP streams. Another Root terminal represents the MG as a whole. The combination between terminals is abstracted as a context. The context can contain multiple terminals, so the relationship between the terminals is described in terms of Topology. For a terminal that has not been associated with another terminal, it is included by a special context called a null (Nul l ) context. Based on this abstract model, the connection of the call is actually the operation of the terminal and the context.

The current MG does not have the ability to process IGMP/MLD protocol messages and multicast routing protocol messages. Therefore, if a media gateway exists on the bearer path, the IGMP/MLD protocol message will be blocked by the media gateway. Summary of the invention

In view of this, the embodiment of the present invention provides a method for implementing a multicast group member management protocol proxy, so that the MG can have the function of a multicast group member management protocol proxy. The method includes an upstream flow interface and at least one downstream flow interface on the MG, and the MG maintains a multicast group member database that summarizes the multicast group member information of all the downstream flow interfaces of the MG, and includes the following steps:

The MG receives the multicast group member management protocol message from the downstream network on the downstream flow interface, and updates the content in the multicast group member database according to the multicast group member management protocol message, and the MG determines the multicast group member database. Whether the change occurs, if yes, sending a multicast group member management protocol message to the upstream network on the upstream flow interface;

and / or,

The MG receives the query message on the upstream flow interface, searches the content of the multicast group member database according to the query message, and if the matched content is found, sends the upstream flow interface to the upstream network. Send a report message.

The embodiment of the present invention further discloses another method for implementing a multicast group member management protocol proxy. An upstream flow interface and at least one downstream flow interface are set on the MG, and the MG maintains and summarizes the multicast group member information of all the downstream flow interfaces. The first multicast group member database, and includes the following steps:

The MG receives the multicast group member management protocol message from the downstream network on the downstream flow interface, and reports the message to the MGC.

The MGC updates the content of the second multicast group member database maintained on the MGC according to the multicast group member management protocol message, and determines whether the second multicast group member database changes. If yes, the MG is in the upstream flow interface. Sending a multicast group member management protocol message to the upstream network; or, the MGC sends an indication to the MG to accept the multicast group member management protocol message, and the MG updates the first multicast group member database according to the indication, and determines the location Whether the first multicast group member database changes, and if so, sending a multicast group member management protocol message to the upstream network on the upstream flow interface;

Or,

After receiving the query message on the upstream flow interface, the MG reports to the MGC, and the MGC searches for the content of the second multicast group member database according to the query message. If the matched content is found, the MG indicates that the MG is upstream. The flow interface sends a message to the upstream network. The MG searches the content of the first multicast group member database after receiving the query message on the upstream flow interface. If the matching content is found, the upstream network is searched. Send a ^ message.

The embodiment of the invention further discloses a method for implementing a multicast group member management protocol proxy. The upstream flow interface of the multicast group member management protocol proxy is bound to a specific multicast group, or is associated with a specific multicast group and multicast. Source address binding.

Another method for implementing a multicast group member management protocol proxy disclosed in the embodiment of the present invention is to configure a multicast group address and/or a multicast data flow between an upstream network and a downstream network in a multicast group member management protocol proxy. The mapping relationship of the source address; and includes the following steps:

Receiving a multicast group member management protocol message on the downstream flow interface;

And multicasting the downlink network in the multicast group member management protocol message according to the mapping relationship The group address and/or the multicast data stream source address is modified to be the multicast group address of the mapped upstream network and/or the multicast data stream source address;

Sending the modified multicast group member management protocol message on the upstream flow interface;

Or, include the following steps:

Receiving a multicast data stream on the upstream flow interface;

Modifying, according to the mapping relationship, the multicast group address and/or the multicast data source source address of the upstream network in the multicast data stream to the multicast group address and/or the multicast data stream of the mapped downstream network. The source address is sent to the downstream stream interface.

The embodiment of the invention also discloses a system for implementing a multicast group member management protocol proxy, including an MG and an MGC.

An upstream flow interface and at least one downstream flow interface are configured on the MG, and a multicast group member database that summarizes multicast group member information of all downstream flow interfaces of the MG is maintained; according to the multicast group member database, The multicast group member management protocol message received by the upstream flow interface is forwarded to the corresponding downstream flow interface, or the report message is sent to the upstream flow interface.

The MGC is configured to send a setup or update command to the MG to set or update a configuration on the MG.

The embodiment of the invention discloses an MG, which comprises means for implementing a multicast group member management protocol proxy function, the device comprising:

An interface configuration module, configured to configure an interface of the MG to be connected to the subnet as an upstream flow interface or a downstream flow interface;

a multicast group database module, configured to maintain a total multicast subscription status of all the downstream flow interfaces of the MG; and a proxy forwarding module, configured to: according to the query message received on the upstream flow interface, in the multicast group database module The content is searched, and if the matched content is found, the upstream flow interface sends a report message to the upstream network; or, according to the multicast group member management protocol message received by the downstream flow interface, the content in the multicast group database module is updated, And determining whether the multicast group member database changes. If yes, sending a multicast group member management protocol message to the upstream network on the upstream flow interface. Another system for implementing a multicast group member management protocol proxy disclosed in the embodiment of the present invention includes an MG and an MGC, and the MG is configured with an upstream flow interface and at least one downstream flow interface, and the MG maintains a group that summarizes all downstream flow interfaces. The first multicast group member database of the member information is broadcasted; the MG is configured to receive the multicast group member management protocol message from the downstream network on the downstream flow interface, and report the multicast group member management protocol message to the MGC; The MG updates the first multicast group member database and/or sends a multicast group member management protocol message according to the indication sent by the MGC; or the MG is used to report the message to the MGC after receiving the query message on the upstream flow interface. And sending a report message to the upstream network on the upstream flow interface according to the indication of the MGC;

The MGC maintains a second multicast group member database that summarizes the multicast group member information of all the downstream flow interfaces; the multicast group member management protocol message reported by the MG and the content in the second multicast group member database Sending a corresponding indication to the MG.

An embodiment of the present invention discloses an MGC, including:

a receiving module, configured to receive a multicast group member management protocol message reported by the MG;

a second multicast group database module, configured to maintain a total multicast subscription status of all the downstream flow interfaces of the MG; and performing, according to the multicast group member management protocol message received by the receiving module, the maintained multicast subscription status Update or search, and notify the multicast command delivery module of the result of the update or search;

The sending module is configured to send a corresponding indication to the MG according to the result of the update or the search.

As shown in the foregoing technical solution, the solution of the present invention maintains an upstream flow interface and a downstream flow interface on the MG, and maintains a multicast group member database for recording multicast group member information, according to the multicast group member database, The multicast group member management protocol message from the upstream flow interface or the downstream flow interface is processed or forwarded, so that the MG implements the function of the multicast group member management protocol proxy.

DRAWINGS

1 is a schematic diagram of networking of a prior art MG and an MGC;

2 is a schematic diagram of an application scenario of the solution of the present invention;

3 is a schematic diagram of another application scenario of the solution of the present invention;

FIG. 4 is a flowchart of processing proxy functions in a direction from a downstream network to an upstream network according to an embodiment of the present invention; Flow chart

FIG. 5 is a flowchart of processing an agent function in a direction from an upstream network to a downstream network according to an embodiment of the present invention;

6 is a schematic diagram of establishing a topology relationship according to an embodiment of the present invention;

FIG. 7 is a block diagram of an internal structure of an MG according to an embodiment of the present invention.

detailed description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings.

The media gateway between the IP networks can serve as the IGMP/MLD proxy entity. A simple application scenario is shown in Figure 2. A border gateway between the IP network 1 and the IP network 2 The MG 202 functions as an IGMP/MLD proxy, and maintains a multicast group member database that aggregates all downstream flow interface multicast group member information of the MG 202 in the MG 202. The IP network 2 is the proxy network of the MG 202, and the MG 202 becomes an querier by electing in the IP network 1, and can send an inquiry message to the IP network 2 and process the IGMP/MLD report message received from the IP network 2 or leave the multicast group. The MG 202 acts as a host in the IP network 1, receives the report message or the leave message from the IP network 1, and updates the multicast group member database according to the report message or the leave message, when the record of the multicast group member database changes. The IGMP/MLD report message and the leave message can be sent to the IP network 1; and the query message sent by the querier in the IP network 1 is responded according to the content of the multicast group member database.

In the G1 IP network 2, a new multicast group member subscribes to the multicast, and the host sends a report to join the multicast group G1. As the multicast querier in the IP network 2, the MG 202 receives the report. If the change of the member database record is caused according to the report message, the report is sent as a host in the IP network 1, and the multicast is required to join. Group Gl. The report is received by the multicast router in the IP network 1, and continues to transmit the join multicast group information to the multicast source tree or the root node of the shared tree according to the existing multicast routing protocol. In Figure 2, if the multicast data source of the multicast group that the host requires to join in IP network 1 is in IP network 2, MG202 may directly receive the multicast data stream sent by the multicast data source without upstream The multicast router 203 obtains the multicast data stream. MG202 forwards multicast data stream to IP network 1. According to the member database record and the multicast group member status on each downstream flow interface.

In addition, the multicast router 203 reported by the receiving MG 202 in the IP network 1 may itself be an IGMP/MLD proxy, which acts as a multicast querier (also a multicast router) in the IP network 1. The host in IP network 2 may also be an IGMP/MLD proxy itself, which acts as a host supporting multicast in IP network 2. In the above two cases, it is actually the case where the IGMP/MLD agents are connected in series, and one or more of the serialized IGMP/MLD agents may be the MGs having the functions of the present invention.

The IGMP/MLD agent (see RFC4605) allows for an upstream stream interface and one or more downstream stream interfaces. The upstream stream interface here can be for all multicasts, as is most scenarios. However, if used in a slightly more complex network structure, an upstream interface may also be used for only one or some multicast groups. For other one or some multicast groups, the upstream stream interface may be different. In a more complicated case, the upstream flow interface of the shared tree and the upstream flow interface of the source tree of different multicast sources may be different for the same multicast group. If the IGMP/MLD proxy can obtain multicast groups and groups. Binding the source address to the upstream stream interface, and binding the upstream stream interface to the multicast group and/or the multicast source address, you can send the IGMP advertisement to the upstream stream corresponding to the multicast to which the report belongs. interface. This is also an enhancement to the I GMP/MLD proxy feature. As shown in Figure 3.

In addition, the IGMP/MLD proxy can also perform proxy between the IPv4 and IPv6 networks. To implement this function, the mapping between the IPv4 address and the IPv6 address of the multicast group address and the multicast source address of the respective network is required. Even if the IGMP/MLD proxy between the same version of the IP network is different, the multicast group address and/or the multicast source address between the upstream and downstream flow interfaces are different. The IGMP/MLD agent maintains the same. Mapping relationship between multicast group address mappings and/or multicast source addresses. And the mapping is implemented on the proxy's IGMP/MLD protocol message and the multicast data stream. This is actually an enhancement to the I GMP/MLD proxy feature.

Multiple downstream flow interfaces share the multicast data stream obtained by the upstream flow interface. The MG needs to maintain the multicast member database and maintain the multicast group member status on each downstream flow interface, that is, maintain the multicast group member information on each downstream flow interface. The status of a multicast group member is also called a multicast group subscription status in this document.

In fact, the implementation of the IGMP/MLD proxy function by the MG described above requires the participation of the MGC. The present invention In the embodiment, the MG and the MGC are used as a multicast group member management protocol proxy system, and the proxy system needs to implement the following three functions:

Attribute configuration function of the upstream stream interface and the downstream stream interface.

The upstream flow interface must be configured on the MG. An upstream upstream interface can be applied to all multicast groups and multicast source addresses, but may be bound to a specific one or more multicast groups (which may further include a multicast source address). As shown in Figure 4. In addition, one or more or all of the downstream stream interfaces that are allowed to be used may be configured for each upstream stream interface. The MG does not process the join multicast group request of the non-downstream stream interface. If the MG has multiple interfaces on the same subnet to which it is connected, only one of them is selected as the upstream or downstream stream interface.

This configuration can be updated in real time by the MGC.

Admission control and resource reservation.

The proxy system maintains, for each downstream flow interface, information about the multicast group address and/or the source address of the multicast data stream that is allowed to be proxyed; the information includes the authority of the host that sends the IGMP/MLD message to the downstream flow interface, and the permissions include permission. Which multicast groups are added, etc.; the information also includes the total bandwidth of each downstream flow interface service, the joined multicast group, and/or the priority level of each multicast data stream source address. Priority is given to high priority traffic when the total bandwidth is insufficient. This feature is not available in all IGMP versions. Earlier versions of IGMP stipulated that hosts could listen to report messages from other hosts and avoid sending duplicate report messages.

Multicast group address and multicast data stream source address mapping.

In some cases, the planning of the source address of the multicast data stream between the IP networks connected to the MG is not uniform. For example, as shown in FIG. 2, the multicast data stream with the source address S2 in the IP network 2 is in the IP network 1. The source address is mapped to S1, that is, after the IP network 2 receives the IGMP report requesting to join the multicast group G1 and the source address of the multicast data stream is S2, the IP gateway 2 forwards the IGMP report to the IP network 1, The report message is translated into an IGMP report that is required to join the multicast group G1 and the source address of the multicast data stream is S1. Or the multicast group address needs to be mapped. For example, the multicast group G2 in the IP network 1 is mapped to the multicast group G1 in the IP network 1. Different IP networks connected by the MG may also run different protocols, such as IPv4 networks. The group member management protocol is IGMP, and the group member management protocol of the IPv6 network is MLD. Its multicast group address and multicast source address obviously need to be mapped.

Therefore, the proxy system maintains multicast group address translation rules and/or multicast data source address translation rules between upstream and downstream flow interfaces. Establish a multicast group address mapping relationship and/or a multicast data source source address mapping relationship between the IP network where the upstream flow interface resides and the IP network where the downstream flow interface resides.

The proxy system (including the MG and the MGC) learns the status of group members in each downstream network and updates the member database through IGMP/MLD messages from the IP network of the downstream flow interface (hereinafter referred to as the downstream network). When the database record changes, the report is sent to the upstream flow interface or the multicast member management protocol message leaving the multicast group. When the query message on the upstream interface is received, the report message is sent according to the content of the member database. Perform the above work while performing admission control and mapping of multicast group addresses and/or multicast source addresses.

According to the functions of the MG and the MGC, the proxy system is divided into the following two modes: Mode 1: Maintain the processing mechanism for IGMP/MLD on the MG, and maintain the member database records according to the IGMP/MLD messages being proxied. The configuration on the MG can also be set or updated by the MGC to the MG. The disadvantage of a purely statically configured solution is that the update of the rules may not be real-time. If the user rights are modified, the multicast group address and multicast data source address mapping rules need to be updated, or the static configuration needs to be updated if the multicast group priority level changes, it is difficult to guarantee the real-time performance of the update, and many rules need to be updated. The MGC uses the information of the control layer or the service layer to generate, so that the MGC needs to have the function of setting or updating the configuration on the MG to the MG.

Manner 2: The IGMP/MLD message is processed by the MGC under the control of the MGC, and the MG reports the received IGMP/MLD message and/or the MGC instructs the MG to send the IGMP/MLD message. In the scenario where the MG is acting as the IGMP/MLD proxy, the MGC instructs the MG to detect the >3⁄4 query message on the upstream flow interface, instructing the MG to send the report message and leave the multicast group message. The MGC instructs the MG to detect the report report message and leave the multicast group message on the downstream flow interface, and send the query message.

The above two methods can also be used in combination. For example, some functions can be automatically configured on the MG through mode 1, for example, periodic query on the downstream interface, query message on the upstream flow interface. Some of the configurations can be updated by the MGC, for example, the MGC synchronizes the status of the multicast group member on the downstream flow interface with the MG, and some functions can be used by the MGC to control the MG to report and send IGMP/MLD messages.

The first embodiment of the proxy system uses the solution of the foregoing mode 1 to implement a plurality of feasible specific solutions. Only one of them is described here, and the principles of other solutions are similar.

Extensions to the H.248 protocol, including:

First, define a H. 248 package impp for MGC settings or update rules.

The MG acting as an IGMP/MLD proxy is located at the junction of two or more IP networks.

Define the properties in the immp package:

(1) The upstream stream interface name (ups t ream interface name, us in), the data type is oct s tr ing , the default value is null, and its value is the interface name of the upstream stream interface;

(2) The downstream stream interface name (downs tream interface name, ds in), the data type is oct s tr ing list , the default value is null, which is the list of available interface names of the downstream stream interface, because the downstream stream interface may More than one, so use a list to indicate.

The upstream flow interface name represents the IP network where the upstream flow interface is connected. The downstream flow interface name represents the IP network where the available downstream flow interface is connected.

The above attribute definition mode is applicable to all multicast groups by default, that is, all multicast groups proxyed by the proxy system use the same upstream stream interface and downstream stream interface. If different multicast groups or different multicast data source addresses can use different upstream and downstream flow interfaces, for example, one interface is the upstream flow interface of multicast group G1, and the other interface is multicast group G2. The upstream upstream interface, or one interface is the multicast upstream interface of the multicast group G1, the multicast source address is S1, and the other interface is the multicast upstream interface of the multicast group G1 and the multicast source address is S2. The above two attribute definition methods need to be further enhanced, including a multicast group identifier and/or a multicast data stream source address, and an upstream stream interface and available corresponding to the multicast group identifier and/or the multicast stream source address. List of downstream stream interfaces.

It is also possible not to limit the downstream flow interface, that is, to allow all interfaces except the upstream flow interface to function as the downstream flow interface. The above upstream flow interface name and the downstream flow interface name parameter may be replaced by the identification attribute of the IP network to which the interface is connected, and the parameter may refer to the expression indicated by the IP domain in H.248.41. Its role is the same as the interface name used. The place where the interface name is mentioned later can be replaced by the IP domain identifier.

2. Define an admission and reserve (aar) signal, which is used by the MGC to update the admission control and resource reservation related configuration to the MG.

This signal defines the following parameters:

(1) The interface name (interface name, in), the data type is octstring, and the default value is null, and its value is the interface name.

(2) Allowed multicast group (allowed group, ag), the data type is string, the default value is null, its value is the allowed multicast group address, which may be IPV4 address or IPV6 address.

(3). Refused group (agg), the data type is string, the default value is null, and its value is the rejected multicast group address, which can be IPV4 address or IPV6 address.

(4) The user agreed group (uag), the data type is string, the default value is null, the value is the source address of the request message and the group allowed to join, the two contents Separated by commas.

(5). User refused group (urg), the data type is string, the default value is null, the value is the source address of the request message and the group that is refused to join, between the two contents Separated by commas.

(6). The multicast group priority (group class, gc), the data type is octstring, the default value is null, and its value is the group address and the corresponding priority.

When the MGC sends the signal to the MG, it indicates the multicast group allowed and denied on an interface, the permission setting of the interface for a certain user, and the priority level of each multicast group on the interface.

Third, the definition signal gasamap, used by the MGC to update the multicast group address and the multicast data stream source address mapping relationship to the MG.

This signal defines the following parameters:

(1). Interface name (interface name, in), data type is octstring, and the default value is empty. Its value is the interface name of the downstream stream interface.

(2) The downstream address to upstream address (datoua), the data type is string list, and the default value is null. The value is the multicast group address and its mapping on the downstream flow interface. The multicast group address on the upstream stream interface. The two contents are separated by commas. Each line in the list represents a mapping relationship.

(3) The downstream source to upstream source (dtou), the data type is string list, the default value is null, and the value is the multicast data stream on the downstream flow interface. The source address and the multicast stream source address on the upstream stream interface to which it is mapped. The two contents are separated by commas. Each line in the list represents a mapping relationship.

When the MGC sends the signal to the MG, it indicates the multicast group address and/or the multicast data source address of the IP network where the downstream flow interface is located and the multicast group address in the IP network where the upstream flow interface resides. Or the correspondence between the source addresses of multicast data streams.

Through the above various signals and attributes, the MGC instructs the MG to set or update the processing rules of the IGMP/MLD message. These signals and attributes can be set to the MG's ROOT terminal or to a non-ROOT terminal. If it is created on a non-ROOT terminal, the interface can be specified through the parameter in and described above. After the interface is specified, the terminal is used to process (including sending and receiving, etc.) the interface specified when the terminal is created. IGMP/MLD messages in the connected IP network.

In addition, the query mechanism on the downstream stream interface needs to be explained. If the message exiting the multicast group is received on the downstream flow interface, you need to send a query message to determine whether there are other users of the multicast group on the downstream network. The downstream flow interface has a periodic query mechanism to prevent the multicast group member management protocol messages from being lost in the IP network, or the host in the downstream network leaves the network before sending out the multicast group message, causing multicast on the downstream flow interface. The group user subscription status does not match the situation in the actual network. In addition, if the upstream flow interface receives the query message, in addition to the mechanism for finding the member database, the query message can be sent to the downstream flow interface, and the multicast group subscription status on the member database and the downstream flow interface can be updated.

The member database and the maintenance of the multicast group member status on each downstream interface are based on the downstream flow connection. The received report message and the leave message are also received according to the status of each multicast timer. I have already received it before, so I won't go into details here.

In IGMP v2, there are ^ message to join the multicast group, and leave message to leave the multicast group. In IGMP v3, the ability to report messages and leave messages is accomplished through report messages. For example, in the report message, the source address filtering condition is MODE_IS_INCLUDE, but the source address list is empty, which actually means leaving the multicast group. Thus, a report message of IGMP v3 can implement multiple reports of IGMP v2. The ability to leave messages and leave messages.

The second embodiment of the proxy system uses the scheme of the foregoing mode 2, that is, the IGMP/MLD message is processed under the control of the MGC through the interaction between the MG and the MGC.

In the second embodiment, the configuration or designation of the upstream stream interface and the downstream stream interface can still use the method of the first embodiment.

On the downstream flow interface, the MGC sets the H.248 event detection IGMP/MLD report message to the MG and/or the message leaving the multicast group. The MGC signals the MG to send an IGMP/MLD query message. The following takes the IGMP protocol as an example. The implementation of the MLD protocol is similar.

The H.248 event includes:

I. Event handling I GMP protocol message i gmpr 1.

The event igmpr l is used to detect IGMP Member Report messages and Leave Group messages.

The event has the following parameters:

(1) The interface name (interface name), the data type is octs tr ing l i s t , and the default value is null, which is the list of interface names of the downstream stream interfaces to detect the event.

If the event is set on the root terminal, the parameter can be used to indicate on which or which downstream flow interface the IGMP report message and the leave group message are detected. If the attribute value is empty, it means that detection is performed on all downstream flow interfaces.

If the event is set on a temporary terminal and the terminal is assigned an interface, then this parameter does not need to be set. The event is reported with the following parameters:

(1) The parameter (interface name, in) and the data type are octstring list, which is the interface name of the downstream stream interface that detected the event.

If the event occurs on a temporary terminal and the terminal is assigned an interface, then the parameter does not need to be reported.

(2) Protocol version (ver), the data type is integer, the default value is 3, and its value is the protocol version. 1, 2, 3 represent versions 1, 2, and 3 of IGMP, respectively.

(3) The message type (type), the data type is integer, the default value is 1, and its value represents the message type. 1 represents the IGMP report message, and 2 represents the IGMP leave group message.

(4) Report content (rl), the data type is string list, the default value is null, and the value represents the content of the report message. Each row in the list represents the content of the report for a group. For IGMP VI and IGMPV2, the content of each line is the group address of a multicast group. For IGMP V3, it is more complicated. The format of each line in the list is as follows:

Multicast group address, type, source address 1, source address 2, ...

Types include the following:

MODE. IS. INCLUDE 1

MODE-IS-EXCLUDE 2

CHANGE-TO. INCLUDE-MODE 3

CHANGE-TO-EXCLUDE-MODE 4

ALLOW-NEW-SOURCES 5

BLOCK-OLD-SOURCES 6

If the line in the parameter rl string list is "224.100.200.3, 1, 192.168.1.2, 192.168.1.3"

It means that the multicast group is added to the multicast group 224.100.200.3, the source address filtering type is M0DE_IS_INCLUDE, and the source address list is 192.168.1.2 and 192.168.1.3, that is, the multicast group 224.100.200.3 is required to be added, but the source address of the qualified multicast data stream must be 192.168. .1.2 or 192.168.1.3. (5) Leave group message ( lg), the data type is string list, the default value is null, and its value represents the list of outgoing multicast groups. Each item in the list is a multicast group address.

On the downstream flow interface, the MG also sends an IGMP/MLD query message. The Query message may be automatically sent by the MG period, or the MG may indicate that the MG periodically sends or is triggered by the upstream stream interface or other events of the downstream stream interface. If the MGC instructs the MG to send an IGMP/MLD query message, the H.248 protocol needs to be extended. Still take IGMP as an example:

2. The event igmpre used by the MGC to instruct the MG to send an IGMP query message.

This event includes the following parameters:

(1) The interface name (interface name, in), the data type is octstring, and the default value is null, which is the interface name of the downstream stream interface. If the event is set on the root terminal, the parameter can be used to indicate on which downstream flow interface the IGMP query message is sent. If the signal is sent on a non-ROOT terminal and the terminal is assigned an interface, then this parameter does not need to be set.

(2) .Version (ver), the data type is integer, the default value is 3, the value is the protocol version, 1, 2, 3 represent IGMP versions 1, 2 and 3.

(3). Waiting time (mrc), the data type is integer, the default value is null, and the value represents the Max Resp Code field in the query message. Indicates the maximum length of time to wait for a response report.

(4) The multicast group address (ga), the data type is string, the default value is null, and the value represents the multicast group address in the query message.

(5). The multicast source address list (sal), the data type is string list, and the default value is null. The value represents the list of multicast source addresses in the query message.

After receiving the igmpre signal of the MGC, the MG constructs and sends an IGMP query message according to the parameters in the signal.

On the upstream flow interface, the H.248 protocol is also required to be extended. The MGC instructs the MG to send the IGMP/MLD report message and the message leaving the multicast group, and the MG reports the event to the upstream router. MGC. This requires the MGC to maintain the multicast group member database in order to generate a report message when it receives the query message. Events that are extended on the upstream stream interface include:

1. The signal mrl is used by the MGC to instruct the NGW to send an IGMP message and leave group message on the upstream flow interface.

The signal includes the following parameters:

(1) The parameter interface name (interface name, in), the data type is oct string, which is the interface name of the upstream stream interface.

If the signal is sent to the root terminal, the parameter can be used to indicate on which upstream flow interface the IGMP message is sent. If the signal is sent to a specially created temporary terminal and the terminal is created on the specified interface, then this parameter does not need to be set. If the MG has only one upstream flow interface for all multicast groups, this parameter does not need to be set.

(2) . Version (ver), the data type is integer, the default value is 3, the value is the protocol version, 1, 2, 3 represent IGMP versions 1, 2 and 3.

(3) . Message type (type), data type: integer, default value 1, its value represents the message type. 1 represents the IGMP report message, and 2 represents the IGMP leave group message.

(4) . Report content (rl), the data type is string list, the default value is null, and the value represents the content of the report message. Each row in the list represents the content of the report for a group. For IGMPvl and IGMPv2, the content of each line is the group address of a multicast group. For IGMP v3, it is more complicated. The format of each line in the list is as follows:

Multicast group address, type, source address 1, source address 2, ...

Types include the following:

MODE. IS. INCLUDE 1

MODE-IS-EXCLUDE 2

CHANGE-TO. INCLUDE-MODE 3

CHANGE-TO-EXCLUDE-MODE 4

ALLOW-NEW-SOURCES 5

BLOCK-OLD-SOURCES 6 If a line in the parameter rl string list is "224.100.200.3, 1, 192.168.1.2, 192.168.1.3", it means that the multicast group 224.100.200.3 is added, and the source address filtering type is

MODE. IS. INCLUDE, the source address list is 192.168.1.2 and 192.168.1.3, which is required to join the multicast group 224.100.200.3, but the source address of the qualified multicast stream must be 192.168.1.2 or

192.168.1.3.

(5). Leave group message (lg), the data type is string list, the default value is null, and its value represents the list of outgoing multicast groups. Each item in the list is a multicast group address.

The report message and the leave group message can also be sent by two different signals. The previous method uses the same signal to deliver, and uses parameters to distinguish the message type.

2. The H.248 event rq is extended by the MG to report the IGMP query message received on the upstream flow interface.

The event has the following parameters:

(1). The interface name (interface name, in), the data type is octstring, and its value is the interface name of the upstream stream interface.

If the event is set to the root terminal, the parameter can be used to indicate on which upstream flow interface the IGMP query message is detected. If the signal is sent to the temporary terminal and the terminal is assigned an interface, then this parameter does not need to be set. If the MG has only one upstream flow interface for all multicast groups, this parameter is not required to be set.

The event is reported with the following parameters:

(1) The interface name (interface name, in), the data type is octstring list, which is the interface name of the upstream stream interface that detected the event. If the event is set on a non-ROOT terminal and the terminal is assigned an interface, or there is only one upstream flow interface on the MG, this parameter does not need to be reported.

(2) .Version (ver), data type: integer, default value is 3, its value is the protocol version, 1, 2, 3 represent IGMP version 1, 2 and 3 respectively.

(3). Waiting time (mrc), data type is integer, default value is null, the value represents the Max Resp Code field in the query message. Indicates the maximum length of time to wait for a response report. (4) The multicast group address (ga), the data type is str ing , the default value is null, and the value represents the multicast group address in the query message.

(5) The multicast source address ( sa l ), the data type is s t r ing l i s t , the default value is null, and the value represents the multicast source address list in the query message.

In addition, some parameters need to be extended to carry other fields in the query message.

The MGC learns the IGMP query message received by the MG through the event, and performs subsequent operations, such as sending a report message.

Through the above extended H.248 packet, the MGC can control the MG to implement the function of the multicast group member management protocol proxy. On this basis, the access control function and the multicast resource reservation function of the multicast group member can be further implemented; and the multicast group address mapping function between the IP network where the upstream flow interface is located and the IP network where the downstream flow interface is located And multicast data stream source address mapping.

The proxy system consisting of the MGC and the MG processed in the second mode is taken as an example. The processing flow for implementing the proxy function in the downstream network is as shown in FIG. 4, and includes the following steps:

Step 401: The MG receives the IGMP/MLD report message or the message leaving the multicast group on the downstream flow interface, and sends the received message to the J MGC.

Step 402: The MGC determines whether the member database needs to be updated by using a locally configured policy, user subscription information, resource status, and records recorded in the multicast group member database maintained on the MGC. If yes, proceed to step 403; otherwise, the MGC A rejection instruction is sent to the MG, and the process ends.

To determine whether you need to update the multicast group member database, there may be multiple cases. The following is a specific example. For the report message requesting to join the multicast group, if the multicast group that the report message is required to join has already been recorded in the multicast group member database, the database does not need to be updated. Otherwise, the multicast group needs to be updated. The record is added to the database; for the message requesting to leave the multicast group, the specific group query message needs to be sent on the downstream interface that receives the message leaving the multicast group to determine the multicast group to leave the MG in the message. Whether the downstream stream interface has other users in the subscription, if there is, there is no need to update the database, otherwise it needs to be updated, that is, the record of the multicast group is deleted from the database. The local policy on the MGC may include configuring a downstream flow interface configuration on the MGC to allow a multicast group address and/or a multicast data source source address list, and/or configuring a multicast group address and/or multicast data on the downstream flow interface. A list of stream source addresses. The judgment in the step may include the following sub-determination steps:

Step 402A: The MGC determines whether the multicast group address and/or the multicast data stream source address carried in the message or the message leaving the multicast group are in the allowed multicast group address and/or multicast data. In the flow source address list, or not in the multicast group address and/or the multicast data source address list, if yes, continue to perform other sub-judgment; otherwise, the MGC sends a rejection indication to the MG.

The local policy on the MGC may further include configuring, on the MGC, the total bandwidth allowed on the downstream flow interface, and the priority of each multicast group and/or the multicast data source address; the determining may include the following :

Step 402B: Determine whether the sum of the multicast bandwidth corresponding to the advertisement message and the existing multicast bandwidth of the downstream flow interface is greater than the total bandwidth of the allowed access, and if not, continue to perform other sub-determinations; Determining whether the multicast corresponding to the report message is allowed according to the priority of the multicast group and/or the source address of the multicast data stream carried by the report message, and if yes, performing other sub-judgment; otherwise, sending a rejection to the MG Instructions.

Step 403: Update the multicast group member database on the MGC.

Step 404: The MGC sends an indication to the MG to send a report message to the upstream network or leave the multicast group message on the upstream flow interface.

In the above process, when forwarding a message to the upstream flow interface, the MGC may instruct the MG to complete the upstream network and the downstream network, because the content of the report message or the outgoing multicast group message sent to the upstream flow interface may be indicated by the MGC in the signal parameter. The multicast group address mapping function and the multicast data source address mapping function are mapped to the multicast group address and/or multicast data source address planned by the downstream network in the message. Address and / or multicast data source address.

The processing flow of the proxy system implementing the proxy function in the upstream network is as shown in FIG. 5, and includes the following steps:

Step 501: After receiving the query message on the upstream flow interface, the MG will query the message on the ^^^ MGC; Step 502: The MGC searches for the content of the multicast group member database according to the query message. If the multicast group address and/or the multicast source address between the upstream network and the downstream network are mapped, the search may also be performed. For example, the two addresses that need to be matched can be unified into the same network; if the matching content is found, step 503 is performed;

Step 503: The MGC instructs the MG to send a report message to the upstream network on the upstream flow interface. The process flow according to the mode 1 may refer to the foregoing process in FIG. 4 and FIG. 5, except that the interaction between the MG and the MGC is omitted, and the MGC is omitted. The processing on the whole is transferred to the MG to complete.

The MG can maintain the status of the multicast group member on the downstream flow interface. The MGC may refuse to join the multicast group request of the downstream network user due to user rights and other reasons. If the multicast group user subscription status on each downstream flow interface is maintained on the MG, and the user joins the multicast group request is rejected, the MGC needs to indicate to the MG to prevent the MG from incorrectly updating the multicast group on the downstream interface. Subscription status. The way to indicate can be as follows:

1. When the MG reports an event and reports to the MGC that the user joins the multicast group, the MGC returns an error code in the response message, indicating that the user is not allowed to join.

2. The MGC rejects the previously reported request to join the multicast group by means of a signal or the like carried in another message.

There is also a way to ensure that the MG maintains the correct multicast group user subscription status on each downstream flow interface. The MGC can also obtain the multicast group subscription status on each downstream flow interface according to the received multicast group message and the leaving multicast group message reported by the received MG. After the MGC policy is controlled, some multicast subscriptions may be rejected. The request, these rejected multicast subscription requests are not used to update the multicast group subscription status on the downstream stream interface, nor to update the member database. The MGC can also obtain the multicast group subscription status of the host in the downstream network through the information obtained in the signaling flow of the service layer or the application layer. When the status of the multicast group on the downstream interface is changed, the MGC can update the MG through the extended H.248 message. The updated information includes the multicast group, the source address filtering condition, and the source address list. The method of expansion is relatively simple and will not be described in detail here.

The MG maintains the multicast group user subscription status on each downstream flow interface. The MG can further The information is derived from the record of the multicast group member database. Then, when the query message on the upstream flow interface is received, the automatic response can be performed without being reported to the MGC, and the MGC instructs to respond. If the multicast group member database on the MG changes, the upstream flow interface sends a report message or leaves the multicast group message.

If the MGC maintains the multicast group address mapping relationship and/or the multicast data source source address mapping relationship between the upstream network and the downstream network, the MGC may extend the H.248 protocol to multicast between the related upstream network and the downstream network. The group address mapping relationship and/or the multicast data source source address mapping relationship are also sent to the MG. The MG also needs to combine the mapping information to forward the multicast data stream according to the multicast group subscription status on each downstream interface. When forwarding a multicast data stream, if the multicast group address and/or the multicast data source source address are mapped, the MG needs to modify the mapped address on the data stream according to the mapping relationship.

If the mapping relationship is fixed, it can also be configured on the MG. The MGC can update the configuration through H.248 messages.

The MG reports the received multicast group member management protocol message to the MGC, which may generate a large number of message interactions. In fact, the MG may perform optimization. For redundant messages, the MG may not report, for example, does not affect the downstream flow interface. The message of the member information of the multicast group can be considered not to be reported, because the result of the admission control of the MGC does not affect the forwarding of the multicast data stream by the MG.

In addition, there may be several situations in which the MG sends a query message on the downstream stream interface. If the message exiting the multicast group is received on the downstream interface, you need to send a query message to determine whether there are other users of the multicast group on the downstream network. The downstream flow interface can also have a periodic query mechanism to avoid the loss of the multicast group member management protocol message in the IP network, or the host in the downstream network leaves the network before sending out the multicast group message, causing the downstream flow interface. The multicast group user subscription status does not match the situation in the actual network. In addition, if the upstream flow interface receives the query message, in addition to the mechanism for finding the member database, the mechanism for querying the downstream flow can be increased, and the multicast group subscription status on the member database and the downstream flow interface can be updated in time.

The two methods of MG configuration and MGC control described above are not mutually exclusive, but can be combined. Use. For example, some functions can be configured to be automatically completed on the MG, some configurations can also be updated by the MGC, and some functions can be controlled by the MGC to control >3⁄4 and send IGMP/MLD messages.

If the event defined in the present invention is not a permanent event, it needs to be set by the MGC to the MG. If it is a permanent event, the MG can automatically detect and report the event.

The method described above solves the related processing problems of the IGMP/MLD protocol on the upstream stream interface and the downstream stream interface. The MG also needs to process and forward related multicast data streams.

If the MGC sends the previously defined signals and events to the root terminal of the MG, the MG receives the multicast data stream on the upstream flow interface, and then according to the multicast group member status of the downstream flow interface, that is, the group on the downstream interface. The status of the subs cr pt ion forwards the multicast data stream to the downstream stream interface that needs to be forwarded. In addition, whether the MG is used as a querier of the downstream network is also a reference condition. If it is not a querier, it does not need to forward the multicast data stream. If you need to map the multicast group address and/or the multicast data source address between the IP network where the upstream flow interface resides and the IP network where the downstream flow interface resides, you need to modify the data flow when forwarding the data flow. Address (multicast group address) and/or multicast stream source address to match the mapping relationship.

As shown in Figure 6, if the MGC sends the previously defined signals and events to the temporary terminal of the designated interface on the MG, the terminal that is designated by the upstream flow interface is called the upstream flow interface terminal, and the downstream flow interface is designated. The terminal is called a downstream stream interface terminal. These terminals can be placed in the same context, and the topology relationship is one-way from the upstream stream interface terminal to the downstream stream interface terminal.

According to the above scheme 1, the internal structure block diagram of the MG is as shown in FIG. 7, and includes:

The interface configuration module 701 is configured to configure an interface that connects the MG to the packet subnet as an upstream flow interface or a downstream flow interface. The interface configuration module 701 can configure an interface connected to a packet subnet as an upstream stream interface bound to a specific multicast group address and/or a multicast source address.

The multicast group database module 702 is configured to store a total multicast subscription status of all the downstream flow interfaces of the MG.

The proxy forwarding module 703 is configured to: according to the query message received on the upstream flow interface, the multicast group The content in the database module 702 is searched, and if the matched content is searched, the upstream flow interface sends a report message to the upstream network; or, the multicast message is updated according to the report message received by the downstream flow interface or the message leaving the multicast group. The content of the group database module 702 is determined, and whether the multicast group member database is changed. If yes, the report message is sent to the upstream network or the multicast group message is sent on the upstream flow interface.

The proxy forwarding module 703 can also include:

a subscription status recording unit, configured to record a multicast subscription status of each downstream flow interface of the MG; a multicast data flow forwarding unit, configured to record the multicast data stream received by the upstream flow interface of the MG according to the subscription status The content in the unit finds the corresponding downstream flow interface and forwards the multicast data stream to the downstream flow interface.

The access control module 704 is configured to configure a multicast group address and/or a multicast data source address list on the downstream flow interface, or configure a multicast group address and/or a multicast data source address list on the downstream flow interface. Determining whether to process the multicast group member management protocol message from the downstream flow interface according to the multicast group address and/or the source address of the multicast data stream carried in the report message received by the downstream flow interface, and if yes, notify the The proxy forwarding module 703 performs corresponding processing.

The access control module 704 further includes:

The bandwidth control unit is configured to configure, on the downstream flow interface, the total bandwidth allowed to access, and determine whether the sum of the multicast bandwidth corresponding to the report message received by the downstream flow interface and the existing multicast bandwidth of the downstream flow interface is greater than Describe the total bandwidth allowed for access, and if not, notify the proxy forwarding module 703 to perform corresponding processing;

and / or,

a priority control unit, configured to configure a priority of each multicast group and/or a multicast source address, and a priority of the multicast group and/or the multicast source address carried by the report message received by the downstream flow interface. And determining whether to notify the proxy forwarding module 703 to perform corresponding processing.

The address mapping module 705 is configured to configure a mapping relationship between a multicast group address and/or a multicast data source source address between the upstream network and the downstream network, and connect the downstream flow interface according to the configured mapping relationship. The multicast group address and/or the source address of the multicast data stream in the received multicast group member management protocol message are modified to the multicast group address of the upstream network and/or the source address of the multicast data stream; and the modified message is And forwarded to the proxy forwarding module 703 for forwarding;

And/or, according to the mapping relationship, modify the multicast group address and/or the multicast data source source address in the multicast data stream received by the upstream flow interface to the multicast group address and/or multicast of the downstream network. The data stream source address, and the modified multicast data stream is forwarded to the proxy forwarding module 703 for forwarding.

The configuration management module 706 is configured to set or update the configuration of the interface configuration module 701, the access control module 704, or the address mapping module 705 according to a configuration or update command from the MGC.

The multicast group timer module 707 is configured to maintain a multicast group timer, and according to the maintained multicast group timer, or the maintained multicast group timer and the multicast group member received by the proxy forwarding module 703 The management protocol message updates the content of the multicast group member database module 702. The multicast group timer module 707 may maintain more than one timer, such as the group membership interval timer, the query interval timer, the active 4 interval timer, and the query response interval timer mentioned above.

The query message sending module 708 is configured to send a query message on the downstream flow interface if the preset trigger condition is met; the triggering condition includes:

The multicast group timer maintained in the multicast group timer 707 is timed out. Specifically, the multicast timer may be a query interval timer or a query response interval timer.

And / or, receiving the leaving multicast group message on the downstream flow interface;

And/or, the proxy forwarding module 703 searches the content of the multicast member database according to the query message received by the upstream flow interface, and cannot find the matched content.

According to the foregoing solution 2, the MGC of the embodiment of the present invention includes:

The sending module is configured to send a corresponding indication to the MG according to the result of the update or the search. The second multicast group database module may further include a policy determining unit, configured to update the group in the second multicast group member database module according to the locally configured policy, the user subscription information, the resource status, or any combination of the foregoing information. Broadcast subscription status.

The MGC may further include an address mapping module, configured to configure a mapping relationship between a multicast group address and/or a multicast data source source address between the upstream network and the downstream network, and configure the MG according to the configured mapping relationship. The multicast group address and/or the multicast source address in the multicast group member management protocol message received by the reported downstream flow interface is changed to the multicast group address of the upstream network and/or the source address of the multicast data stream, and Sending the multicast group address and/or the multicast data stream source address of the upstream network to the MG through the sending module.

The MLD protocol is similar to the IGMP protocol. The IGMP message, the leaving group message and the query message, and the MLD's multicast listener report (Mul t icas t Li s tener Report) message, the multicast listener is completed (Mul t icas t Li s tener Done) message and multicast listener query (Mul t icas t Li s tener Query) message, the content of the message is basically the same, the main difference is that the multicast group address and source address are IPV6 addresses, The implementation details are not described here.

By extending the H.248 protocol, the MG and the MGC form a multicast group member management protocol proxy system, and configure an upstream flow interface and a downstream flow interface, and a multicast group member database, so that the MG can forward multicast messages and groups. Broadcast data stream.

If the IGMP/MLD proxy is between the IPv4 and IPv6 networks, while running IGMP and running MLD on the other side, it will not work properly. If the configurations of multicast group addresses and/or multicast source addresses on both sides of the IGMP/MLD proxy are inconsistent, mapping is required. For example, the request for the multicast group G1 on the downstream flow interface, where the multicast group address is the SI, and S1 is the address identifier in the downstream network address plan. On the upstream flow interface, the multicast group address must be in accordance with the upstream network. Address planning, the multicast group address is represented as S2 in the address plan of the upstream network, so S1 needs to be mapped to S2. The inventive scheme introduces an address mapping to enable the IGMP/MLD proxy to process correctly.

In addition, the solution of the present invention also introduces an admission control function, which filters the request of the user to join the multicast group according to the user authority, and the IGMP/MLD proxy maintains the received multicast group member management protocol message. Member database, and for this purpose as a basis for sending multicast group member management protocol messages. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

Claim

A method for implementing a multicast group member management protocol proxy, characterized in that: an upstream flow interface and at least one downstream flow interface are set on the media gateway MG, and the MG maintains multicast of all downstream flow interfaces of the MG. Group member information for the multicast group member database, and includes the following steps:

and / or,

The MG receives the query message on the upstream flow interface, and searches for the content of the multicast group member database according to the query message. If the matched content is found, the upstream flow interface sends a report message to the upstream network.

The method for implementing a multicast group member management protocol proxy according to claim 1, wherein the MG maintains multicast group member information on each downstream flow interface, and the method further includes:

The MG receives the multicast data stream on the upstream flow interface, and forwards the multicast data stream to the corresponding downstream flow interface according to the multicast group member information on each downstream flow interface.

The method for implementing the multicast group member management protocol proxy according to claim 1, wherein the setting an upstream flow interface and the at least one downstream flow interface on the MG includes: setting the upstream flow interface and The downstream flow interface is applicable to all multicast groups or to specific multicast groups and/or multicast source addresses.

The method for implementing a multicast group member management protocol proxy according to claim 1, wherein the multicast group member management protocol message includes an Internet Group Management Protocol (IGMP) report message, and the IGMP leaving the multicast group message, the group The broadcast listener finds the multicast listener report of MLD or the multicast listener completion message of MLD.

The method for implementing a multicast group member management protocol proxy according to claim 1, wherein the method comprises: The MG periodically sends an inquiry message on the downstream flow interface.

Or, after receiving the leaving multicast group message on the downstream flow interface, the MG sends a query message on the downstream flow interface.

Or the searching for the content of the multicast group member database according to the query message, if the matching content is not found, the method further includes: sending the query message on the downstream flow interface.

The method for implementing a multicast group member management protocol proxy according to claim 1, wherein configuring a downstream flow interface to allow a multicast group address and/or a multicast data source source address list or a downstream flow on the MG The interface prohibits the multicast group address and/or the multicast data stream source address list.

Before the content of the multicast group member database is updated according to the multicast group member management protocol message, the method further includes: determining, by the MG, the multicast group carried in the message or the message leaving the multicast group Whether the address and/or the multicast data stream source address is in the allowed multicast group address and/or the multicast data stream source address list, or is not in the prohibited multicast group address and/or the multicast data stream source. In the address list, if yes, the subsequent steps are performed.

The method for implementing a multicast group member management protocol proxy according to claim 1, wherein the MG is configured to allow total bandwidth allowed on the downstream flow interface, and/or each multicast group and/or group. The priority of the broadcast stream source address;

Then, before updating the content in the multicast group member database according to the report message, the method further includes:

The MG determines whether the sum of the multicast bandwidth corresponding to the report message and the existing multicast bandwidth of the downstream flow interface is greater than the total bandwidth of the allowed access, and if not, performing the subsequent step;

Or,

Determining whether the multicast corresponding to the report message is allowed according to the priority of the multicast group and/or the source address of the multicast data stream carried in the report message, and if yes, performing the subsequent step.

The method for implementing a multicast group member management protocol proxy according to claim 1, wherein the multicast group address and/or the multicast data stream source address between the upstream network and the downstream network are maintained on the MG. Mapping relations; Before sending the multicast group member management protocol message to the upstream network on the upstream flow interface, the method further includes:

Modifying, according to the mapping relationship, the multicast group address and/or the multicast data source address of the downstream network in the multicast group member management protocol message to the multicast group address and/or the multicast data stream of the upstream network. source address.

The method for implementing a multicast group member management protocol proxy according to claim 2, wherein the multicast group address and/or the multicast data stream source address between the upstream network and the downstream network are maintained on the MG. Mapping relations;

And the forwarding the multicast data stream to the corresponding downstream flow interface includes:

Modifying, according to the mapping relationship, the multicast group address and/or the multicast data source source address of the upstream network in the multicast data stream to the multicast group address and/or the multicast data stream of the mapped downstream network. The source address, and then the multicast data stream is sent.

The method for implementing a multicast group member management protocol proxy according to claim 8 or 9, wherein the address mapping relationship is a mapping between addresses of the same IP version address or addresses of different IP versions. .

The method for implementing a multicast group member management protocol proxy according to any one of claims 1 to 9, wherein, when the multicast group timer is maintained on the MG, the multicast group member database is updated. The content includes: updating the content of the multicast group member database according to the state of the multicast group timer, or the status of the multicast group timer and the multicast group member management protocol message.

The method for implementing a multicast group member management protocol proxy according to any one of claims 1 to 9, wherein the method further comprises: the media gateway controller MGC issuing a setting or updating command to the MG, The configuration on the MG is set or updated.

A method for implementing a multicast group member management protocol proxy is characterized in that: an upstream flow interface and at least one downstream flow interface are set on the MG, and the MG maintains the summary of the multicast group member information of all the downstream flow interfaces. A multicast group member database, and includes the following steps:

The MG receives the multicast group member management protocol message from the downstream network on the downstream flow interface, and sends the message to the MGC. Newspaper

Or,

The method for implementing a multicast group member management protocol proxy according to claim 13, wherein the MG maintains multicast group member information on each downstream flow interface, and the method further includes:

The MG receives the multicast data stream on the upstream flow interface, and forwards the multicast data stream to the downstream flow interface according to the multicast group member information on each downstream flow interface.

The method for implementing a multicast group member management protocol proxy according to claim 13, wherein the multicast group timer is maintained on the MG, and the MGC updates the MGC according to the multicast group member management protocol message. The content of the second multicast group member database maintained on the network further includes:

The MG reports the multicast timer to the MGC, and the MGC updates the content in the second multicast group member database according to the report information. Alternatively, the MGC maintains a multicast timer, and the MGC further performs the multicast timer according to the multicast timer. The status updates the content in the second multicast group member database.

The method for implementing a multicast group member management protocol proxy according to claim 13, wherein the MG receives the multicast group member management protocol message from the downstream network on the downstream flow interface, and only affects the first The multicast group member management protocol message of the multicast group member database content is reported to the MGC.

The method for implementing a multicast group member management protocol proxy according to claim 13, wherein the MG receives the multicast group member management protocol message from the downstream network on the downstream flow interface, and further includes: MGC basis to the MGC. The locally configured policy, the user subscription information, the resource status, or any combination of the above information updates the content in the second multicast group member database, or indicates to the MG whether to accept the multicast group member management protocol message.

The method for implementing the multicast group member management protocol proxy according to claim 13, wherein the method further comprises: the MG periodically sending the query message on the downstream flow interface, or the MG is in the downstream flow according to the indication of the MGC. The query message is sent on the interface, or the MG sends a query message on the downstream flow interface after receiving the message from the downstream flow interface.

The method for implementing a multicast group member management protocol proxy according to claim 13, wherein the multicast group address and/or the multicast data stream source between the upstream network and the downstream network are maintained on the MGC or the MG. Mapping relationship of addresses;

Before the MG sends the multicast group member management protocol message to the upstream network on the upstream flow interface, the MG further includes:

The MGC or the MG modifies the multicast group address and/or the multicast data source source address in the multicast group member management protocol message to the multicast group address and/or the multicast data stream of the upstream network according to the mapping relationship. source address.

The method for implementing a multicast group member management protocol proxy according to claim 14, wherein the multicast group address and/or the multicast data stream source address between the upstream network and the downstream network are maintained on the MG. Mapping relations;

The MG modifies the multicast group address and/or the multicast data stream source address in the multicast data stream to the multicast group address and/or the multicast data stream source address of the downstream network according to the mapping relationship, and then The MG sends the multicast data stream.

A method for implementing a multicast group member management protocol proxy, characterized in that: an upstream flow interface of a multicast group member management protocol proxy is bound to a specific multicast group, or is associated with a specific multicast group and multicast. Source address binding.

22. A method for implementing a multicast group member management protocol proxy, characterized in that: in a multicast group member management protocol proxy, configuring a multicast group address and/or a multicast data stream source between the upstream network and the downstream network The mapping relationship of the address; and includes the following steps:

Modifying, according to the mapping relationship, the multicast group address and the I or multicast data source address of the downstream network in the multicast group member management protocol message to the multicast group address and the I or group of the mapped upstream network. Broadcast data stream source address;

Or, include the following steps:

Receiving a multicast data stream on the upstream flow interface;

A system for implementing a multicast group member management protocol agent, comprising: an MG and an MGC, wherein the MG maintains a multicast group member database that summarizes multicast group member information of all downstream flow interfaces of the MG, Configuring an upstream flow interface and at least one downstream flow interface; and forwarding the multicast group member management protocol message received by the upstream flow interface to the corresponding downstream flow interface according to the multicast group member database, or sending a report to the upstream flow interface Message

The system for implementing a multicast group member management protocol proxy according to claim 23, wherein the MG is further configured to maintain a multicast group timer, according to the state of the multicast group timer, or a group. The state of the multicast group timer and the multicast group member management protocol message received by the downstream stream interface update the content of the multicast group member database.

25. An MG, comprising: a function for implementing a multicast group member management protocol proxy function Device, the device includes:

An interface configuration module (701), configured to configure an interface of the MG to be connected to the subnet as an upstream flow interface or a downstream flow interface;

a multicast group database module (702), configured to maintain a total multicast subscription status of all downstream flow interfaces of the MG;

The proxy forwarding module (703) is configured to search for content in the multicast group database module (702) according to the query message received on the upstream flow interface, and if the matched content is found, the upstream flow interface is upstream. The network sends a report message; or, according to the multicast group member management protocol message received by the downstream flow interface, updating the content in the multicast group database module (702), and determining whether the multicast group member database changes, and if so, Then, the multicast group member management protocol message is sent to the upstream network on the upstream flow interface.

The MG according to claim 25, wherein the interface configuration module (701) configures an interface connected to the packet subnet as an upstream stream bound to a specific multicast group address and/or a multicast source address. interface.

The MG according to claim 25, wherein the MG further comprises: an access control module (704) configured to configure a multicast group address and/or a multicast data source address on the downstream flow interface. The multicast group address and/or multicast data carried in the multicast group member management protocol message received by the downstream flow interface is configured on the downstream flow interface. The source address determines whether the multicast group member management protocol message from the downstream flow interface is processed. If yes, the proxy forwarding module is notified (703) to perform corresponding processing.

The MG according to claim 27, wherein the access control module (704) further comprises:

The bandwidth control unit is configured to configure, on the downstream flow interface, the total bandwidth allowed to access, and determine whether the sum of the multicast bandwidth corresponding to the report message received by the downstream flow interface and the existing multicast bandwidth of the downstream flow interface is greater than Describe the total bandwidth allowed for access, and if not, notify the proxy forwarding module (703) to perform corresponding processing; and / or,

a priority control unit, configured to configure a priority of each multicast group and/or a multicast source address, and a priority of the multicast group and/or the multicast source address carried by the report message received by the downstream flow interface. And determining whether to notify the proxy forwarding module (703) to perform corresponding processing.

The MG according to claim 25, wherein the MG further comprises: a multicast group timer module (707), configured to maintain a multicast group timer, and according to the maintained multicast group timer Or the maintained multicast group timer and the multicast group member management protocol message received by the proxy forwarding module (703) update the content of the multicast group member database module.

The MG according to claim 29, wherein the MG further comprises: a query message sending module (708), configured to send a query message on the downstream stream interface if a preset trigger condition is met; The triggering conditions include:

The timer maintained in the multicast group timer expires;

Receiving a message leaving the multicast group on the downstream flow interface;

Or, the content of the multicast group member database is searched according to the query message received by the upstream flow interface, and the matched content cannot be found.

The MG according to any one of claims 25 to 30, wherein the proxy forwarding module (703) further comprises:

The MG according to any one of claims 25 to 30, wherein the MG further comprises:

The address mapping module (705) is configured to configure a mapping relationship between the multicast group address and/or the multicast data source source address between the upstream network and the downstream network, and receive the downstream flow interface according to the configured mapping relationship. The multicast group address and/or the multicast stream source address in the multicast group member management protocol message are modified to a multicast group address and/or a multicast data source address of the upstream network, and sending the modified multicast group member management protocol message to the proxy forwarding module (703);

Or, configured to modify the multicast group address and/or the multicast source address in the multicast data stream received by the upstream flow interface to the multicast group address and/or multicast of the downstream network according to the mapping relationship. The data stream source address, and the modified multicast data stream is sent to the proxy forwarding module (703).

The MG according to any one of claims 25 to 30, wherein the MG further comprises: a configuration management module (706), configured to configure a module according to a configuration or update command from the MGC (701), the configuration of the access control module (704) or the address mapping module (705) is set or updated.

A system for implementing a multicast group member management protocol proxy, comprising: an MG and an MGC, wherein the MG is configured with an upstream flow interface and at least one downstream flow interface, and the MG maintains and summarizes multicast of all downstream flow interfaces. The first multicast group member database of the group member information; the MG is configured to receive the multicast group member management protocol message from the downstream network on the downstream flow interface, and report the multicast group member management protocol message to the MGC; Updating the first multicast group member database and/or sending a multicast group member management protocol message according to the indication sent by the MGC; or the MG is configured to report the query message to the MGC after receiving the query message on the upstream flow interface, and Sending a report message to the upstream network on the upstream flow interface according to the indication of the MGC;

35. An MGC, characterized in that:

The MGC according to claim 35, wherein the second multicast group database module further comprises:

And a policy determining unit, configured to update, according to the locally configured policy, the user subscription information, the resource status, or any combination of the above information, the multicast subscription status in the second multicast group member database module.

The MGC according to claim 35 or 36, wherein the MGC further comprises an address mapping module, configured to configure a multicast group address and/or a multicast data stream source between the upstream network and the downstream network. Modify the mapping of the address to the upstream network. The mapping between the multicast group address and/or the multicast data source address in the multicast group member management protocol message received by the downstream traffic interface reported by the MG is modified according to the configured mapping relationship. The multicast group address and/or the multicast data stream source address, and the multicast group address and/or the multicast data stream source address of the upstream network are sent to the MG through the sending module.