CN1302649C - Method for realizing message transmission and transaction reliability processing of media gateway control protocol - Google Patents

Abstract

The present invention relates to a method for realizing the message transmission and the business reliability processing of a medium gateway control protocol (H. 248), which relates to the technical field of communication. In the method, an association is introduced in an H. 248 protocol layer; a local end message transmitter identifier (MID) and an opposite end message transmitter identifier (MID) are corresponding to an association; H. 248 protocol user application layer establishes a corresponding relation of the association and a connection according to practical situations; business reliability processing is carried out on the association, message receiving processing or message sending processing is carried out according to the corresponding relation of the association and the connection. The present invention provides a method which conveniently and reliably completes H. 248 message transmission and business reliability processing when identifier sets of sending ends and receiving ends of connections and messages.

Description

Method for Realizing Media Gateway Control Protocol Message Transmission and Transaction Reliability Processing

technical field

The invention relates to the technical field of communication, in particular to a method for realizing media gateway control protocol (H.248) message transmission and transaction reliability processing.

Background technique

The Media Gateway Control Protocol (H.248) is a protocol applied between the Media Gateway Controller and the Media Gateway. The Media Gateway Controller is responsible for controlling the call status related to the Media Gateway. Complete the conversion of media formats between different networks under control. As shown in Figure 1, it is a schematic diagram of the position of the H.248 protocol in the TCP/IP protocol layered model. The messages of the H.248 protocol are mainly transmitted on the IP. (TCP, Transmission Control Protocol) or User Datagram Protocol (UDP, User Datagram Protocol), etc. UDP provides a connectionless message service, while TCP provides a connection-oriented streaming service. The so-called connection-oriented refers to Guarantee the correctness of data transmission, the same order, and no loss. The so-called streaming service means that the user's data transmission and reception are all character streams, instead of encapsulating the entire data block sent by the user each time in a message. In a certain sense, the H.248 protocol is further divided into the H.248 protocol layer and the H.248 protocol user application layer.

Socket (Socket) is a programming interface provided by the transport layer for the application layer, and provides connection-oriented or connectionless communication services in the form of client-server (client-server) to the application program. From the perspective of the application program, the main component of the socket It is a five-tuple (protocol, local address, local port number, peer address, peer port number), for connection-oriented TCP:

On the media gateway controller side, the process of the application server (server) is as follows:

1. Call the socket() function to create the main server;

2. Call the bind() function to specify the local address and port number;

3. Call the listen() function to prepare to receive the connection request;

4. Call the accept() function to monitor the connection request. After receiving the connection request, accept will return a new socket number, the address and port number of the client (client), and the application will use the new socket to communicate with the client in the future;

5. ... (Other processes such as closing process etc. will not be described here).

On the media gateway side, the process of applying the client (client) is as follows:

1. Call the socket() function to create a Socket;

2. Call the bind() function to specify the local address and port number;

3. Call the connect() function to connect to the specified peer. At this point, a communication connection is established, and H.248 messages can be sent and received;

4. ... (Other processes, such as the closing process, etc. will not be described here).

When the H.248 protocol message is transmitted on TCP, although TCP provides a reliable transmission mechanism, because TCP is a stream-based protocol, for the transaction-oriented H.248 protocol, the transaction in the message may still be lost , if the transaction sent by the media gateway controller is lost and cannot get a timely response, it may lead to repeated sending, which will lead to unpredictable status of the media gateway after executing the command. Therefore, the H.248 protocol stipulates some requirements for protecting the reliable transmission of transactions. The H.248 protocol layer or the H.248 protocol user application layer shall realize and guarantee the reliable transmission of transactions according to the protocol requirements.

An H.248 message is composed of multiple transactions. The transactions contained in the message are independent. Each message has a message header, which contains an identifier identifying the sender of the message, called MID (Message Identifier), H The .248 protocol stipulates that a logical media gateway controller or media gateway should have a unique MID, and the requirements for transaction reliability transmission in the H.248 protocol are all based on the same MID.

Since the H.248 protocol message is transmitted on the TCP connection, the reliable transaction processing of the transmitted message needs to be based on the same MID. Therefore, when the MID and the connection can correspond one-to-one, the H.248 protocol layer or the H. 248 protocol, the user application layer can directly process the transaction reliability of the connection that has completed sending and receiving, but the connection and MID are not fixed one-to-one correspondence, and there may be complex situations such as many-to-one or one-to-many. Therefore, the prior art cannot implement H.248 message transmission and transaction reliability processing under these circumstances.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the disadvantages of the existing technology that when the identifier groups at the two ends of the connection and message sending and receiving are not in one-to-one correspondence, the connection cannot be directly used for transaction reliability processing, and to provide a connection and message When the identifier groups at the sending and receiving ends have different corresponding relationships, the method for H.248 message transmission and transaction reliability processing can be realized conveniently and reliably.

The technical scheme that the present invention adopts for solving the problems of the technologies described above is:

The method for realizing media gateway control protocol message transmission and transaction reliability processing includes the following steps:

A. Introduce association (association) at media gateway control protocol (H.248) protocol layer, a local message sender identifier (MID) corresponds to an association with a peer message sender identifier (MID);

B, the H.248 protocol user application layer establishes the corresponding relationship of association and connection (Connection) according to the actual situation;

C. Perform transaction reliability processing on the association, and perform message receiving or sending processing according to the correspondence between the association and the connection.

In the step B, when a media gateway is divided into multiple virtual gateways or multiple media gateways have only one network interface and only one connection is established, the MIDs of the media gateway controllers correspond to multiple MIDs of different media gateways. Different associations, and different associations correspond to the same connection.

When the media gateway controller performs sending processing, it determines the association of the message to be sent according to the peer media gateway MID to which the message is to be sent. send on

When the media gateway controller performs receiving processing, it receives an H.248 message from the connection, determines the association of the received message according to the peer media gateway MID in the message header, and completes the transaction reliability processing on the association.

When the media gateway is sending the message, it determines the association of the message to be sent according to the peer media gateway controller MID to which the message is to be sent, and when it is ready to send after completing the transaction reliability processing on the association, it finds the corresponding connection through the association, and completes the send on connection;

When the media gateway receives the H.248 message from the connection, it distributes the message to the relevant associations according to the implementation strategy of the media gateway to complete the reliability processing of the transaction.

If the media gateway is a plurality of virtual gateways divided according to physical terminals, then the implementation strategy can be that the functional module responsible for distribution by the media gateway first solves the physical terminal corresponding to the command contained in the message, and determines the corresponding physical terminal according to the physical terminal. Which virtual gateway to distribute the received message to the association corresponding to the virtual gateway.

In the step B, when a plurality of connections are established between a media gateway controller and a media gateway, there is an association between the MID of the media gateway controller and the MID of the media gateway, and the association is different from multiple corresponding to the connection.

When the media gateway controller performs sending processing, it determines the association of the message to be sent according to the peer media gateway MID to which the message is to be sent. which connection to send on;

During receiving processing, no matter from which connection the H.248 message is received, it corresponds to the same association, and the transaction reliability processing on the association is completed.

The sending strategy of the media gateway controller may be to decide on which connection to send according to flow control.

When the media gateway is sending the message, it determines the association of the message to be sent according to the MID of the peer media gateway controller to which the message is to be sent. When it is ready to send the message after completing the transaction reliability processing on the association, it determines which send on the connection;

During receiving processing, no matter from which connection the H.248 message is received, it corresponds to the same association, and the transaction reliability processing on the association is completed.

When the message sent by the media gateway is a response to the request message sent by the media gateway controller, the sending policy of the media gateway is to send a response message on the received connection.

The beneficial effects of the present invention are: the present invention introduces association (association), and makes MID and connection respectively establish corresponding relationship with association, a local MID and a opposite end MID uniquely correspond to an association, like this, association can be regarded as For a logical connection, the H.248 protocol layer does not need to care about the actual physical connection, it only needs to complete the transaction reliability processing according to the association, and the H.248 protocol user application layer establishes the correspondence between the association and the connection according to the actual situation relationship.

The invention provides a method for conveniently and reliably completing H.248 message transmission and transaction reliability processing when connections and MIDs are in various correspondences.

Description of drawings

Fig. 1 is a schematic diagram of the position of the H.248 protocol in the TCP/IP protocol layered model diagram;

FIG. 2 is a schematic diagram of the corresponding relationship between association and connection when there is only one connection between a media gateway controller and multiple media gateways in the present invention;

FIG. 3 is a schematic diagram of the corresponding relationship between association and connection when multiple connections are established between a media gateway controller and a media gateway according to the present invention.

Detailed ways

Below according to accompanying drawing and embodiment the present invention will be described in further detail:

H.248 protocol messages are transmitted on TCP connections. In order to ensure the reliable transmission of transactions in H.248 messages, transaction reliability processing needs to be implemented. If transaction reliability processing is directly implemented for connections, in some cases in actual situations Difficult to deal with.

The present invention introduces association (association) at the H.248 protocol layer, and makes MID not directly correspond to connection (connection), but makes MID and connection respectively establish correspondence with association, like this, makes MID and connection indirectly establish correspondence through association Relationship, a local MID and a peer MID uniquely correspond to an association, so transaction reliability can be realized on an association. The association can be regarded as a logical connection. For the H.248 protocol layer, it does not need to care about the actual physical connection. It only needs to complete the transaction reliability processing according to the association, which is established by the H.248 protocol user application layer according to the actual situation. Just start the corresponding relationship between association and connection.

When the relationship between connection and MID is not one-to-one, there may be one-to-many or many-to-one situations between connection and MID. The specific description is as follows:

1. As shown in Figure 2, when a media gateway is divided into multiple virtual gateways or multiple media gateways have only one network interface and only one connection is established, since each logical gateway has a MID, the correspondence between the connection and the MID A relationship is a one-to-many situation.

The following is a detailed introduction from the side of the media gateway controller and the side of the media gateway:

1. Media gateway controller side:

(1) Establishment of corresponding relationship:

The local MID (the MID of the media gateway controller) and the peer MID1 (the MID of the media gateway 1) correspond to association1, and the local MID (the MID of the media gateway controller) and the peer MID2 (the MID of the media gateway 2) correspond to association2. The connection corresponding to association1 is connection; the connection corresponding to association2 is also connection.

(2) Send processing:

For the media gateway controller, the media gateway identified by the MID to which the H.248 message is to be sent is determined, so the association for sending the message is determined, and the H.248 messages on different associations are processed separately for transaction reliability. That is, the transaction reliability processing is carried out for the MID. When it is ready to send, the corresponding connection is found through the association, and the sending on the connection is completed.

(3) Receiving and processing:

The H.248 message received from the connection can determine the association receiving the message according to the peer media gateway MID identifier in the message header, and complete the transaction reliability processing on the association.

2. Media gateway side:

(1) Establishment of corresponding relationship:

For example, for the media gateway 1, the local MID1 (the MID of the media gateway 1) and the peer MID (the MID of the media gateway controller) correspond to association1, and the connection corresponding to the association1 is connection.

(2) Send processing:

For the media gateway, the MID-identified media gateway controller to which the H.248 message is to be sent is unique, so the association for sending the message is determined. Find the corresponding connection and complete the sending on the connection.

(3) Receiving and processing:

How to distribute the H.248 messages received from the connection to the relevant associations to complete transaction reliability processing is the specific implementation strategy of the media gateway. If media gateway 1 and media gateway 2 are two virtual gateways respectively, and the two virtual gateways The gateway is divided according to the physical terminal, and the function module responsible for the distribution of the media gateway can first solve the physical terminal corresponding to the command contained in the message. It can be known which virtual gateway the physical terminal belongs to, so that the received The message is distributed to the association corresponding to the virtual gateway.

2. As shown in FIG. 3 , when multiple connections are established between one media gateway controller and one media gateway, the corresponding relationship between connections and MIDs is many-to-one.

The following describes in detail from the media gateway controller and the media gateway side respectively:

1. Media gateway controller side:

(1) Correspondence establishment:

The local MID (media gateway controller MID) and the peer MID (media gateway MID) correspond to the association, connection1 corresponds to the association, and connection2 also corresponds to the association.

(2) Send processing:

For the media gateway controller, the media gateway identified by the MID to which the H.248 message is to be sent is determined, so the association for sending the message is also determined. For multiple connections, which connection to send on specifically belongs to the sending strategy of the media gateway controller, such as determining which connection to send on according to flow control.

(3) Receiving and processing:

No matter from which connection the H.248 message is received, it corresponds to the same association, and the transaction reliability processing on the association is completed.

2. Media gateway side:

(1) Correspondence establishment:

The local MID (media gateway MID) and the peer MID (media gateway controller MID) correspond to the association, connection1 corresponds to the association, and connection2 also corresponds to the association.

(2) Send processing:

For the media gateway, the MID-identified media gateway controller to which the H.248 message is to be sent is unique, so the association for sending the message is determined. Multiple connections, which connection to send on belongs to the sending strategy of the media gateway. Usually, for the media gateway, the sent message is mostly a response to the request message sent by the media gateway controller, so the response should be sent on the received connection information.

(3) Receiving and processing:

No matter from which connection the H.248 message is received, it corresponds to the same association, and the transaction reliability processing on the association is completed.

The invention provides a method for conveniently and reliably completing H.248 message transmission and transaction reliability processing when connections and MIDs are in various correspondences.

Claims (9)

1. A method for realizing media gateway control protocol message transmission and transaction reliability processing, comprising the following steps: A. The association is introduced at the protocol layer of the media gateway control protocol, and a local message sender identifier corresponds to an association with a peer message sender identifier; B. The user application layer of the media gateway control protocol establishes the corresponding relationship between association and connection according to the actual situation; C. Perform transaction reliability processing on the association, and perform message receiving or sending processing according to the correspondence between the association and the connection. 2. The method for realizing media gateway control protocol message transmission and transaction reliability processing according to claim 1, characterized in that: in the step B, when a media gateway is divided into a plurality of virtual gateways or a plurality of media gateways When there is only one network interface and only one connection is established, the sender identifiers of the media gateway controller and the sender identifiers of different media gateways correspond to multiple different associations, and different associations correspond to the same connection. 3. the method for realizing media gateway control protocol message transmission and transaction reliability processing according to claim 2, is characterized in that: when the media gateway controller carries out sending processing, prepare to send to the opposite end media gateway sender identification according to message The symbol determines the association of sending messages, and when the transaction reliability processing on the association is completed and the message is ready to be sent, the corresponding connection is found through the association, and the sending on the connection is completed; When the media gateway controller performs receiving processing, it receives the media gateway control protocol message from the connection, determines the association of the received message according to the peer media gateway sender identifier in the message header, and completes the transaction reliability processing on the association. 4. The method for realizing media gateway control protocol message transmission and transaction reliability processing according to claim 2 or 3, characterized in that: the media gateway is prepared to send to the opposite end media gateway controller according to the message when sending processing The sender identifier determines the association of the sent message. When the transaction reliability processing on the association is completed and the message is ready to be sent, the corresponding connection is found through the association, and the sending on the connection is completed; When the media gateway is receiving and processing, it receives the media gateway control protocol message from the connection, distributes the message to the relevant associations according to the implementation strategy of the media gateway, and completes the reliability processing of the transaction. 5. The method for realizing media gateway control protocol message transmission and transaction reliability processing according to claim 4, characterized in that: if the media gateway is a plurality of virtual gateways divided according to physical terminals, then the implementation strategy can be The function module responsible for the distribution by the media gateway first solves the physical terminal corresponding to the command contained in the message, and determines which virtual gateway it belongs to according to the physical terminal, so as to distribute the received message to the association corresponding to the virtual gateway. 6. the method for realizing media gateway control protocol message transmission and transaction reliability processing according to claim 1 is characterized in that: in the described step B, when a media gateway controller and a media gateway have established multiple For each connection, there is an association between the sender identifier of the media gateway controller and the sender identifier of the media gateway, and the association corresponds to multiple different connections. 7. The method for realizing media gateway control protocol message transmission and transaction reliability processing according to claim 6, characterized in that: when the media gateway controller sends and processes, it prepares to send to the opposite end media gateway sender identification according to the message The character determines the association of the sent message, and when the transaction reliability processing on the association is completed and the message is ready to be sent, it is determined on which connection to send it according to the flow control; During receiving processing, no matter from which connection the MGCP message is received, it corresponds to the same association, and the transaction reliability processing on the association is completed. 8. The method for realizing media gateway control protocol message transmission and transaction reliability processing according to claim 6 or 7, characterized in that: the media gateway is prepared to send to the opposite end media gateway controller according to the message when sending processing The sender identifier determines the association of the sent message, and when it is ready to send after completing the transaction reliability processing on the association, determine which connection to send according to the sending strategy of the media gateway; During receiving processing, no matter from which connection the MGCP message is received, it corresponds to the same association, and the transaction reliability processing on the association is completed. 9. The method for realizing media gateway control protocol message transmission and transaction reliability processing according to claim 8, characterized in that: when the message sent by the media gateway is a response to the request message sent by the media gateway controller, the The sending strategy of the media gateway is to send a response message on the received connection.

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