CN1855930B - Method for transmitting conference control messages based on primary protocol of dialog - Google Patents

Abstract

The method for realizing the transmission of conference control messages based on the SIP protocol of the present invention mainly includes: Step S1: establishing a call between SIP user agents; The control message is transmitted between network entities; Step S3: After receiving the SIP message encapsulated with the conference control message, the peer SIP user agent performs inverse transformation to generate a corresponding conference control message. The conversion in the above step S2 refers to converting the conference control message supported by the H.323 protocol into a character string in an XML-like format. In this way, the SIP protocol can be used to realize the transmission of conference control messages through the above method, so that a video conference system based on the SIP protocol can be realized.

Description

A realization method of transmitting conference control messages based on session initiation protocol

technical field

The invention belongs to the technical field of network communication, and in particular relates to a method for realizing the transmission of video conference control messages based on the Session Initiation Protocol (SIP protocol for short). the

Background technique

At present, video conferencing systems based on broadband Internet Protocol (Internet Protocol) (hereinafter referred to as IP) networks are developing rapidly, but most video conferencing systems are basically based on the two major framework agreements of the ITU-T H.320 protocol. And H.323 agreement to establish. The H.320 protocol is an earlier video conferencing standard of the ITU-T, which is based on a circuit-switched network; the H.323 protocol is a multimedia communication standard based on a packet-switched network. Although the H.323 protocol is mature and well-defined, its protocol and networking are complex, costly, and poor in efficiency and scalability. At the same time, only H.323 terminals can participate in the conference in the video conferencing system based on the H.323 protocol, which is also its limitation. one of sex. the

The SIP protocol is relatively simple, all messages are coded in text, and has strong flexibility and scalability, which enables the SIP protocol to provide more and more flexible services than the H.323 protocol. There are more advantages in the interoperability of commands, and its networking is relatively simple. the

However, the current SIP protocol has no specific regulations on how to realize video conferencing control, and most of the drafts are still in the discussion stage and have not reached the stage of implementation. the

Contents of the invention

In view of this, the purpose of the present invention is to provide a method for realizing the transmission of conference control messages based on the SIP protocol. On the one hand, the user can utilize the SIP protocol to form a video conference system based on a broadband IP network; So that both the SIP terminal and the H.323 terminal can participate in the conference of the multipoint conference control unit (Multipoint Controller Unit) (hereinafter referred to as MCU) based on the SIP protocol or the MCU based on the H.323 protocol. the

This method is to use the relatively mature conference control mechanism of the H.323 protocol to convert its conference control message into a character string in XML format (not a real XML format), encapsulate it in the message body of the SIP message, and use the SIP message in the network Conference control messages are sent between entities to implement a video conference. the

The implementation method of the transmission conference control message based on the SIP protocol of the present invention is characterized in that it comprises the following steps:

Step S1: Establish a call between SIP user agents;

Step S2: The SIP user agent in the call uses the relevant message encapsulation of the SIP protocol to convert the conference control message supported by the H.323 protocol into a conference control message of a character string in XML format, so that it can be transmitted between network entities;

Step S3: After receiving the SIP message encapsulated with the conference control message, the peer SIP user agent performs inverse conversion to generate a corresponding conference control message. the

The SIP user agent in the above step S1 may be a SIP terminal, or an application server or a soft switch acting as a SIP user agent. the

The rule of converting the conference control message supported by the H.323 protocol into an XML-like format in the above step S2 includes the following steps:

Step S21: converting the specific message type of the H.323 protocol into the starting tag (the starting tag) and the ending tag (the ending tag) of the root element (root element) in XML format;

Step S22: If there are parameters in the message, convert the parameter names into element tags (tags) in XML format and nest them in the root element, which is equivalent to the child elements (childelements) of the above root element;

Step S23: If the parameter also includes sub-parameters, that is, the parameter is equivalent to a structure, then convert the sub-parameter name into an element tag in XML format, completely nested in the above-mentioned sub-element, and there can be no intersection between elements ; If there are parameters in the sub-parameters, the operation of step S23 is executed in a loop;

Step S24: fill in the corresponding parameter value between the start tag and the end tag as the content of each element. the

Wherein, the element tags in the above step S22 include a start tag and an end tag. And when the parameter name in the above step S22 is relatively long, take its abbreviation as the element tag (tag). the

In addition, the inverse transformation in the above-mentioned step S3 is carried out according to the above-mentioned transformation rules. the

In this way, the SIP protocol can be used to realize the transmission of conference control messages through the above method, so that a video conference system based on the SIP protocol can be realized. the

The specific implementation of the method of the present invention will be further described in detail with preferred embodiments below in conjunction with the accompanying drawings. The above and other objects, features and advantages of the present invention will be apparent to those skilled in the art from the detailed description of the method of the present invention. the

Description of drawings

Fig. 1 is a system flow diagram of the realization of the conference control message of the SIP user agent. the

Fig. 2 is a flow chart of a SIP terminal participating in a video conference of an MCU based on the H.323 protocol through a soft switch. the

Fig. 3 is a flow chart of a video conference in which a SIP terminal and an H.323 terminal participate in an MCU based on the SIP protocol through a soft switch. the

Detailed ways

The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. the

The system flow diagram of the SIP user agent conference control message system shown in Figure 1 is applicable to all SIP terminals based on this implementation method, as well as application servers or soft switches that act as SIP user agents. Please see Figure 1:

Step 101, first establish a call between SIP user agents, because the conference control function is established on the basis of the call;

Step 102, according to the operation action of the user, the SIP user agent converts the corresponding conference control message into an XML-like format;

Step 103, encapsulating the conference control message in XML-like format into the message body of the SIP message, and sending it to the opposite end. After the opposite end receives it, it performs an inverse transformation to generate a corresponding conference control message. the

Fig. 2 is a flow chart describing the video conference process where a SIP terminal joins an MCU based on the H.323 protocol through a soft switch. Here, the INFO message of the SIP protocol is used as the message body of the conference control message. This is just an example to illustrate the conversion and transmission of conference control messages based on the SIP protocol. The networking mode is not limited to this mode, and the flow is not limited to the message flow in the figure. the

Step 201, the SIP terminal initiates a call (INVITE) message to the softswitch;

Step 202, the softswitch carries out the number routing analysis according to the called number, finds that this is a call to the MCU based on the H.323 protocol, then performs protocol adaptation conversion, and sends the call (Setup) message of the H.323 protocol to the MCU;

Step 203, MCU sends a ringing (Alerting) message to the softswitch;

Step 204, the softswitch performs protocol conversion and sends a ringing (180Ringing) message to the SIP terminal;

Step 205, MCU answers the call, and sends a connection (Connect) message to the softswitch;

Step 206, the softswitch sends a 200OK response message to the SIP terminal through protocol conversion;

Step 207, the SIP terminal sends an ACK confirmation message to the softswitch;

Step 208, after the conference call is established, the MCU informs the terminal that it is in a multipoint conference, and sends an H.245 conference control message to the softswitch;

Step 209, the softswitch converts the H.245 conference control message into a character string in XML-like format and encapsulates it in the INFO message and sends it to the SIP terminal;

Step 210, the SIP terminal sends a 200OK response message without a message body;

Step 211, the SIP terminal sends a request for chairman control message to the softswitch, encapsulated with an INFO message;

Step 212, the softswitch converts the SIP message body into an H.245 conference control message and sends it to the MCU;

Step 213, the soft switch sends a 200 OK response message to the SIP terminal. the

Figure 3 describes the video conferencing process in which a SIP terminal and an H.323 terminal join an MCU based on the SIP protocol through a softswitch. At this time, the MCU is equivalent to the role of a SIP user agent. the

Step 301, the SIP terminal initiates a call (INVITE) message to the softswitch;

Step 302, the softswitch carries out the number routing analysis according to the called number, and finds that this is a call to the MCU based on the SIP protocol, so the call message is forwarded to the MCU, and the softswitch is equivalent to the role of a proxy server at this moment;

Step 303, MCU sends ringing (180Ringing) message to softswitch;

Step 304, the soft switch forwards the ringing (180Ringing) message to the SIP terminal;

Step 305, the MCU answers the call, and sends a 200OK response message to the softswitch;

Step 306, the softswitch forwards the 200OK response message to the SIP terminal;

Step 307, after receiving the 200OK response message, the SIP terminal sends an ACK confirmation message to the softswitch;

Step 308, the soft switch forwards the ACK confirmation message to the MCU;

Step 309, after the conference call is established, the MCU informs the terminal that it is in a multipoint conference, and the conference control message is converted into an XML-like format, encapsulated in an INFO message, and sent to the softswitch;

Step 310, the softswitch forwards the INFO message to the SIP terminal;

Steps 311-312 are the 200OK response message of the INFO message sent by the SIP terminal and forwarded by the softswitch;

Step 313, the SIP terminal sends a message requesting the chairman control right to the softswitch, and the conference control message is converted and encapsulated in the INFO message;

Step 314, the softswitch forwards the INFO message to the MCU;

Steps 315-316 are the 200OK response message of the INFO message sent by the MCU and forwarded by the softswitch;

Step 317, the H.323 terminal initiates a call (Setup) message to the softswitch;

Step 318, the softswitch carries out the number routing analysis according to the called number, and finds that this is a call to the MCU based on the SIP protocol, so the protocol adaptation conversion is carried out, and the call (Setup) message of the H.323 protocol is converted into that of the SIP protocol Call (INVITE) message, sent to MCU;

Step 319, the MCU returns a ringing (180Ringing) message to the softswitch;

Step 320, the soft switch converts the ringing message of the SIP protocol into a ringing (Alterting) message of the H.323 protocol, and sends it to the H.323 terminal;

Step 321, the MCU answers the call, and sends a 200OK response message to the softswitch;

Step 322, after the softswitch receives the 200OK response message, it is converted into a connection (Connect) message of the H.323 protocol and sent to the H.323 terminal;

Step 323, the soft switch sends an ACK confirmation message to the MCU;

Step 324, after the conference call of the H.323 terminal is established, the MCU informs the terminal that it is in a multipoint conference, and encapsulates the conference control message in the SIP message body and sends it to the softswitch;

Step 325, the softswitch converts the SIP message body into an H.245 conference control message, and sends it to the H.323 terminal;

Step 326, the softswitch sends the 200OK response message of INFO to the MCU;

Step 327, the H.323 terminal sends an H.245 conference control message requesting the chairman control message to the softswitch;

Step 328, the softswitch converts the received H.245 conference control message into the message body of the SIP message, and sends the INFO message to the MCU;

In step 329, the MCU sends a 200 OK response message of the INFO message to the softswitch. the

The working principle of the present invention is described in detail above, and several typical network structure message flows are given, but this is only a vivid example for easy understanding, and should not be regarded as limiting the scope of the present invention. Similarly, any ordinary professional in the technical field can make various possible equivalent changes or replacements according to the technical solution of the present invention and the description of its preferred embodiments, but all these changes or replacements should belong to the scope of the present invention. The scope of the claims.

Claims (6)

1. the implementation method of the transmission meeting control messages of dialogue-based initiation protocol, this implementation method is utilized the H.323 meeting controlling mechanism of agreement, it is characterized in that comprising the steps:

Step S1: between the session initiation protocol user agent, set up and call out;

Step S2: be in related news encapsulation that session initiation protocol user agent in the conversation uses session initiation protocol H.323 the meeting control messages of agreement support be converted into the meeting control messages of the character string of class XML form, it is transmitted between network entity;

Step S3: after opposite end session initiation protocol user agent receives the conversation initiating protocol message that is packaged with the meeting control messages, carry out inverse transformation, generate corresponding meeting control messages.

2. implementation method according to claim 1 is characterized in that the session initiation protocol user agent among the above-mentioned steps S1 comprises conversation beginning protocol terminal and the application server and the soft switch of serving as session initiation protocol user agent role at least.

3. implementation method according to claim 1, the rule that the meeting control messages that it is characterized in that the support of above-mentioned H.323 agreement is converted into the character string of class XML form comprises the steps:

Step S21: H.323 the concrete type of message of agreement is converted into the start-tag and the end-tag of the root element of XML form;

Step S22: if parameter is arranged in the message, then parameter name is converted into the element tags of XML form, is nested among the root element, promptly be equivalent to the daughter element of above-mentioned root element;

Step S23: if also comprise subparameter in the parameter, promptly parameter is equivalent to structure, then the subparameter title similarly is converted into the element tags of XML form, fully is nested among the above-mentioned daughter element, and between the element intersection can not be arranged; If also have parameter, the operation of the execution in step that then circulates S23 in the subparameter;

Step S24: the corresponding parameters value is filled between start-tag and the end-tag, as the content of each element.

4. implementation method according to claim 3 is characterized in that the element tags among the above-mentioned steps S22 comprises start-tag and end-tag.

5. implementation method according to claim 4 is characterized in that when the parameter name among the above-mentioned steps S22 is long, gets its abbreviation as element tags.

6. implementation method according to claim 3 is characterized in that inverse transformation among the above-mentioned steps S3 is according to above-mentioned transformation rule reverse.

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