WO2007053981A1

WO2007053981A1 - A method for implementing the media switch in the voice service of the h.323 protocol

Info

Publication number: WO2007053981A1
Application number: PCT/CN2005/001910
Authority: WO
Inventors: Qiaoxia Wu; Yongdong Pan; Gaofeng Fan
Original assignee: Zte Corporation
Priority date: 2005-11-14
Filing date: 2005-11-14
Publication date: 2007-05-18
Also published as: CN101194483B; CN101194483A

Abstract

A method for implementing the media switch in the voice service of the H.323 protocol of the present invention ,in which the process of the media switch is initiated by the softswitch control equipment, the type of the media switch is the voice media and the switched terminal is the H.323 terminal, performs the flow of the media switch corporately needed in a plurality of the value added service by the negotiation of the H.245 media control signaling, and in the media negotiation, it performs the media negotiation using the virtual media in the case that it does not know the partner media. It applies the media switch of fastly calling and slowly calling user without the influence of the type of the interconnected procotol, and applies the case of the media switch needed in a plurality of the implementation of value added service.

Description

Method for realizing media switching in voice service of H.323 protocol

The invention belongs to the field of data communication, and relates to a method for implementing media switching of the '1,323 protocol in a softswitch system, and particularly relates to a method for implementing media switching in a voice service of the H.323 protocol. Background technique

The Next Generation Network (NGN network) and the softswitch system provide a large number of rich and colorful value-added services based on the traditional telephone voice service. The H.323 protocol often needs to be temporarily implemented when implementing these value-added services. Turn off the media channel that the terminal originally opened, and transfer its media to a new point (such as a media server that provides voice services, etc.).

The H.450.X series protocol encapsulates a series of letters defined by the H450.1 Supplementary Service (Application Protocol Data Unit, APDU) and its defined H.225 call signaling message. The process completes the value-added service and the media switching process involved, but the application of the H.450.X series protocol defines a set of processes for each service, and the terminal and the control device need to support the H.450.X protocol, which is more complicated. .

Currently, the H.245 protocol in the H.323 protocol suite is a media control protocol, and media negotiation between endpoints can be completed through the H.245 process. The V.2 version of the H.323 protocol introduces the concept of a fast call, allowing media negotiation to be completed by a fast start unit while the call is being established. The H.323 protocol V2 version also introduces third-party rerouting and terminal capability settings. (Terminal Capability Set NULL) (hereinafter referred to as TCSNULL) message usage. Summary of the invention

In view of the above, the problem to be solved by the present invention is how to use the media negotiation defined by the H.245 media control signaling to complete the media switching process commonly required in various value-added services, and consider the fast, slow call to H.323 protocol media switching. Impact.

Therefore, the object of the present invention is to provide a method for implementing media handover in a voice service of the H.323 protocol, which completes the media of the communication terminal from the original endpoint to a new one through negotiation of H.245 media control signaling. The endpoints flexibly and conveniently implement the media switching process required in various value-added services, and also consider the impact of fast call and slow call processes and cross-protocol interworking on the media switching process.

To achieve the above object, a method for implementing media switching in a voice service of the H.323 protocol of the present invention is applicable to a caller of a fast call type, wherein the media handover process is initiated by a softswitch control device, and the type of media handover For voice media, and the switched terminal is an H.323 terminal, the method includes the following steps:

Step 1: The calling party sends a setup message with the calling media to the softswitch control device. Step 2: Since some services need to block the media stream called to the calling party before the called party picks up the phone, the softswitch The control device can construct the fake media and send a setup message with the fake media to the called party;

Step 3: The softswitch control device sends a ringing message with no media and a connect message of the media with the media server to the above-mentioned calling party, and passes the Real-time Transport Protocol. (hereinafter referred to as RTP) to call the above caller Sound.

Step 4: The called party picks up the phone and sends a connect message to the softswitch control device.

Step 5: The softswitch control device determines whether the connection message has the called media, and if yes, the call is a fast type, and step 7 is performed; otherwise, the called is a slow type, and the step is performed. 6;

Step 6: The softswitch control device and the called party perform media negotiation through the H.245 process, and the softswitch control device obtains the called media.

Step Ί: The softswitch control device switches the calling media to the called party by using H.245 media control signaling.

Step 8: The softswitch control device switches the called media to the calling party by using H.245 media control signaling.

Step 9: The above caller and the above called party call.

In the foregoing step 6, the media negotiation performed by the softswitch control device and the called party through the H.245 process is to perform media negotiation using the fake media and the called party.

In addition, the following steps must be performed before performing step 7 above:

The above-mentioned calling party and the above-mentioned softswitch control device sequentially perform two-way master-slave determination and capability exchange, and both the calling party and the softswitch control device can receive the acknowledgement message of the other party.

Moreover, when the called type is fast, the following steps are performed before the step 8 is performed: the called party and the softswitch control device perform the two-way master-slave determination and capability exchange in sequence, and the called party and the softswitch Both parties to the control device can receive the confirmation message from the other party.

Further, the above step 7 mainly includes the following steps: Step 701: The softswitch control device sends a request type (RequestMode) message with a switched media type to the calling party.

Step 702: After receiving the request type (RequestMode) message, the calling party sends a request type acknowledgement (RequestModeAck) message to the softswitch control device.

Step 703: The foregoing calling party and the above softswitch control device close the logical channel through two directions

The (CloseLogicalChannel) message and the CloseLogicalChannelAck message close the respective open media channels;

Step 704: The foregoing calling party and the softswitch control device open the required media channel by bidirectional OpenLogical Channel (OpenLogicalChannel) message and Open logical channel acknowledgement (OpenLogicalChannelAck) message.

Further, the foregoing step 8 mainly includes the following steps:

Step 801: The softswitch control device sets a terminal (TerminalCapabilitySetNULL) message to the called terminal.

Step 802: After the called party receives the terminal capacity set (TerminalCapabilitySetNULL) message, the terminal responds to the softswitch control device with a terminal capability setting confirmation (TerminalCapabilitySetAck) message;

Step 803: The foregoing called party and the softswitch control device close the respective open media channels by using a bidirectional CloseLogicalChannel message and a CloseLogicalChannelAck message;

Step 804: The softswitch control device receives the foregoing terminal capability setting confirmation.

(TerminalCapabilitySetAck) message, and confirming that the media channel is completely closed, and sending the non-empty terminal capability setting with the switched media type to the called party (TerminalCapabilitySet) message;

Step 805: After receiving the foregoing non-empty terminal capability setting (Terminal CapabilitySet) message, the called party completes the two-way capability exchange process with the softswitch control device, and returns a non-empty terminal capability setting confirmation to the softswitch control device. a terminal CapabilitySetAck) message; Step 806: After receiving the non-empty terminal capability setting confirmation (TerminalCapabilitySetAck) message of the called response, the softswitch control device initiates a bidirectional master-slave determination and capability exchange operation with the called party;

Step 807: The above called party and the above softswitch control device open the required media channel by bidirectional OpenLogical Channel message and OpenLogicalChannelAck message.

To achieve the above object, a method for implementing media switching in a voice service of the H.323 protocol of the present invention is applicable to a calling party of a slow call type, wherein the media switching process is initiated by a softswitch control device, and the media switching is performed. The type is voice media, and the switched terminal is an H.323 terminal. The method includes the following steps:

Step 1: The calling party sends a setup message without the calling media to the softswitch control device. Step 2: The softswitch control device sends a setup message without the media to the called party; Step 3: The softswitch control device transmits a ringing message with no media and a connect message of the media without the media server by forwarding to the above-mentioned calling party;

Step 4: The calling party and the softswitch control device perform media negotiation through the H.245 process, and the calling party obtains the media of the media server and listens to the calling tone through the RTP. Step 5: The called party picks up the phone, The softswitch control device sends a connect message without the called media; Step 6: The softswitch control device constructs a fake medium;

Step 7: The softswitch control device and the called party perform media negotiation through the H.245 process, and the softswitch control device obtains the called media.

Step 8: The softswitch control device switches the calling media to the called party by using H.245 media control signaling.

Step 9: The softswitch control device switches the called media to the calling party by using H.245 media control signaling.

Step 10: The above caller and the above called party call.

In the foregoing step 7, the media negotiation performed by the softswitch control device and the called party through the H.245 process is to perform media negotiation using the fake media and the called party.

Further, the foregoing step 8 mainly includes the following steps:

Step 801: The softswitch control device sends a request type (RequestMode) message with the switched media type to the calling party.

Step 802: After receiving the request type (RequestMode) message, the calling party sends a request type acknowledgement (RequestModeAck) message to the softswitch control device.

Step 803: The foregoing calling party and the softswitch control device close the respective opened media channels by using a bidirectional CloseLogicalChannel message and a CloseLogicalChannelAck message;

Step 804: The foregoing calling party and the softswitch control device open the required media channel by bidirectional OpenLogical Channel (OpenLogicalChannel) message and OpenLogical Channel Ack message.

Further, the above step 9 mainly includes the following steps: Step 901: The softswitch control device sets a terminal (Terminal Capability Set NULL) message to the called terminal.

Step 902: After receiving the terminal capacity setting (NerminalCapabilitySetNULL) message, the called terminal returns a terminal capacity setting confirmation (TerminalCapabiHtySetAck) message to the softswitch control device;

Step 903: The foregoing called party and the softswitch control device close the respective open media channels by using a bidirectional CloseLogicalChannel message and a CloseLogicalChannelAck message;

Step 904: The softswitch control device receives the terminal capability setting confirmation (TerminalCapabilitySetAck) message, and confirms that the media channel is completely closed, and sends a non-empty terminal capability setting (TerminalCapabilitySet) with the switched media type to the called party. ) message

Step 905: After receiving the foregoing non-empty terminal capability setting (Terminal CapabilitySet) message, the called party completes the two-way capability exchange process with the softswitch control device, and returns a non-empty terminal capability setting confirmation to the softswitch control device ( a terminal CapabilitySetAck) message; Step 906: After receiving the non-empty terminal capability setting confirmation (TerminalCapabilitySetAck) message of the called response, the softswitch control device initiates a two-way master-slave determination and capability exchange operation with the called party;

Step 907: The above called party and the softswitch control device open the required media channel by using a bidirectional OpenLogicalChannel message and an OpenLogicalChannelAck message.

The foregoing calling media includes at least a media type supported by the calling party, and the calling media internet protocol Media information such as the Internet Protocol (IP) address and the calling media port number; for the caller of the fast call type, the media type of the fake media is the same as the media type supported by the calling party, and the fake media IP address is Unreachable IP address (for example, 127.0.0.1), the fake media port number is optional. For the slow call type, the media type of the fake media includes various commonly used media types, and the fake media IP address is unreachable. The IP address (for example, 127.0.0.1), the fake media port number is optional; the media of the media server includes at least a ring back tone media and a prompt tone medium; and the foregoing media negotiation by the H.245 process includes at least a master-slave determination operation, The capability exchange operation and the snoring media channel operation; the call tone includes at least a color ring tone and a prompt tone; and the called media includes at least media information supported by the called party, the called media IP address, and the called media port number.

Further, in order to be compatible with media switching using different H.245 media control signaling, the softswitch control device may be configured to match different switched terminal types or different switched terminal nodes, etc. One of two media switching processes.

In addition, the method of the present invention can also initiate the above media switching process by using other intelligent service control devices instead of the above soft handover control device.

The invention adopts the H.245 media control signaling to complete the media switching process in the voice service of the H.323 protocol. In the media negotiation, the media negotiation is implemented by using the fake media in the case of unknown media, which is suitable for fast calling and slow. The media switching of the fast calling user is not affected by the type of cross-protocol, and can be used for media switching in various value-added service implementations.

The above and other objects, features and advantages of the present invention will become more <RTIgt; DRAWINGS

FIG. 1 is a schematic diagram of a main process of calling a fast call type according to the method of the present invention; FIG. 2 is a schematic diagram of a main flow of a caller being a slow call type according to the method of the present invention; FIG. 3 is a preferred embodiment of the present invention; In the example, the fast H.323 user calls the number one number of the ring tones service process, and the fast H.323 user bound by the number one number picks up the phone;

4 is a flow chart of a CRBT No. 1 service for a fast H.323 subscriber to call a one-number number in a preferred embodiment of the present invention, wherein a slow H.323 subscriber bound by a one-number number is off-hook;

FIG. 5 is a flow chart of a CRBT number one service for a slow H.323 user to call a one-number number in a preferred embodiment of the present invention, wherein an H.323 user bound by the first number is off-hook. detailed description

The one-number service allows multiple terminal users to be bound to the same one-number number. When a user calls the one-number number, multiple bound users ring at the same time. After one of the ringing users picks up the phone, The call between the off-hook user and the calling party is connected, and the call of other terminal users is released.

The specific implementation steps of the H.323 protocol media switching method of the present invention are described below in conjunction with the implementation process of the No. 1 service on the H.323 protocol side. The main called user may not be the user under the same softswitch, and the call path may also span other protocol types and other control devices. The present invention mainly focuses on the signaling process of the H.323 protocol side. For convenience of description, the IP address of the calling party and the type of media used in the embodiment are embodied, but the invention is not limited by these contents. In order to cover the process of the method of the present invention with fewer embodiments, a more typical example is selected, and the main called party adopts different 11245 signaling switching procedures, and the media switching used in other value-added services can also use the present invention. Media switching method. 1 is a schematic diagram of a main flow of a caller being a fast call type according to the method of the present invention, and FIG. 3 is a first-pass service flow of a fast H.323 subscriber calling a one-number number in a preferred embodiment of the present invention, where The fast H.323 user bound to the number is off-hook, and the ringer is placed on the media server through the media server. Referring to FIG. 1 and FIG. 3 simultaneously, the method mainly includes the following steps: Step 101: The calling party sends a setup message to the softswitch control device, where the message carries the calling media;

Step 102 and step 103, the softswitch control device sends a setup message to the plurality of called users bound by the one-number communication, wherein the message carries the fake media, but the media type is the media type supported by the calling party;

Step 104 and step 105, the plurality of called parties ring simultaneously;

Step 106: The softswitch control device sends an alerting message to the calling party. Step 107: The softswitch control device sends a connect message to the calling party, where the message is sent to the ringback media, that is, the media server. Media

Step 108: The caller listens to the CRBT through the RTP, and selects the voice media type as G711A; Step 109, the called party picks up the phone, and the selected voice media type is G711U;

Step 110: The softswitch control device releases other called user calls.

Step 111: Before using the H.245 media control signaling to switch the calling media, the calling party and the softswitch control device perform the two-way master-slave determination, and both parties need to receive the master slave confirmation (MasterSlaveDeterminationAck) message;

Step 112: Before using the H.245 media control signaling to switch the calling media, the calling party and the softswitch control device perform a two-way capability exchange, and both parties need to receive a terminal capability setting confirmation (Terminal Capability Set Ack) message of the other party; Step 113, the softswitch control device sends a request type (RequestMode) message to the calling party to switch the calling media, wherein the switched media type is the called media G711U;

Step 114: After receiving the request type (RequestMode) message, the calling party returns a request type acknowledgement (RequestModeAck) message to the softswitch control device.

Step 115: The calling party and the softswitch control device respectively close the voice media channel opened by the party;

Step 116: The caller and the softswitch control device open a new voice media channel, where the media type is G711U. At this time, the caller has obtained the called media, and may send an RTP voice packet to the called party.

Step 117: Before the called media is switched by using the H.245 media control signaling, the called party and the softswitch control device perform a two-way master-slave determination, and both parties need to receive a master-slave determination (Ack) message of the master;

Step 118: Before using the H.245 media control signaling to switch the called media, the called party and the softswitch control device perform bidirectional capability exchange, and both parties need to receive a terminal capability setting confirmation (TerminalCapabilitySetAck) message of the other party;

Step 119: The softswitch control device sets a terminal (Terminal Capability Set ULL) message to the called terminal to pause the called media.

Step 120: The called party returns a terminal capability setting confirmation (TerminalCapabilitySetAck) message to the softswitch control device.

Step 121: The above called party and the softswitch control device respectively close all media channels opened by the party; Step 122: The softswitch control device receives the terminal capability setting confirmation (TerminalCapabilitySetAck) message of the called party, and confirms that all the media channels are closed, and sends a non-empty terminal capability setting (TerminalCapabilitySet) message to the called party. , wherein the message includes the current media type of the calling party, that is, G711U;

Step 123: The called party returns a terminal capability setting confirmation (TerminalCapabilitySetAck) message to the softswitch control device.

Step 124: The called party and the softswitch control device re-determine the two-way master-slave determination. Step 125: The called party sends a terminal capability setting (Terminal Capability Set) message to the softswitch control device, where the message includes the called party support. Step 126, the softswitch control device sends a confirmation (TerminalCapabilitySetAck) message to the called terminal.

Step 127: The called party and the softswitch control device open a new voice media channel, where the media type is G711U, and the called party obtains the calling media at this time;

Step 128: The above-mentioned calling party is called.

4 is a first-pass service flow for a fast H.323 user to call a one-number number in a preferred embodiment of the present invention, in which a slow H.323 user bound to the first number picks up the phone and sends a call through the media server. Put the ring tones. Please refer to FIG. 1 and FIG. 4 at the same time, which mainly includes the following steps: Step 201 to Step 208 are the same as Step 101 to Step 108, and the calling party hears the ring back tone;

Step 209, the called party picks up the phone, and sends a connect message to the softswitch control device, where the message does not have the called media;

Step 210: The called party and the softswitch control device perform bidirectional master-slave determination; Step 211, the called party and the softswitch control device perform bidirectional capability exchange; Step 212, the above called party and the softswitch control device open the voice media channel, wherein the media type is G711U;

Step 213: The softswitch control device releases other called user calls.

Step 214 to step 219 are the same as step 111 to step 116, and the calling media is switched from the media server to the called party;

Step 220 to step 228 are the same as steps 119 to 127, and the called media is switched from the fake media to the calling party;

Step 229, the above-mentioned calling party is called.

2 is a schematic diagram of a main flow of a caller being a slow call type according to the method of the present invention, and FIG. 5 is a first-pass service flow of a slow H.323 user calling a one-number number in a preferred embodiment of the present invention; The H323 user bound to the first one picks up the phone and puts the ring back tone to the calling party through the media server. Please refer to FIG. 2 and FIG. 5 at the same time, which mainly includes the following steps:

Step 301: The calling party sends a setup message to the softswitch control device, where the message does not carry the calling media.

Step 302 and step 303, the softswitch control device sends a setup message to a plurality of called users bound to the one-number communication, wherein the message does not carry media;

Step 304 and step 305, the plurality of called parties ring simultaneously;

Step 306, the softswitch control device sends an alerting message to the calling party; Step 307, the softswitch control device sends a connect message to the calling party; Step 308, the calling party and the softswitch control The device performs bidirectional master-slave determination. In step 309, the calling party and the softswitch control device perform bidirectional capability exchange, where the softswitch control device sends a terminal capability setting (TerminalCapabilitySet) message packet. The media type of the media server used to put the ring tones;

Step 310, the caller and the softswitch control device open the voice media channel, wherein the selected media type is G711A;

Step 311, the foregoing caller listens to the ring back tone;

Step 312, the called party picks up the phone, and sends a connect message to the softswitch control device, where the message does not carry media;

Step 313, the called party and the softswitch control device perform bidirectional master-slave determination; Step 314, the called party and the softswitch control device perform bidirectional capability exchange, where the softswitch control device sends the terminal capability setting ( TerminalCapabilitySet) messages include various media types commonly used;

Step 315, the above called party and the softswitch control device open the voice media channel, wherein the selected media type is G711U;

Step 316, the softswitch control device releases other called user calls;

Step 317: After all the media information, such as the media type, the IP address, and the media port number supported by the called party, are sent to the calling side of the softswitch control device, the softswitch control device sends a request type (RequestMode) message to switch the calling party. The medium, wherein the media type in the request type message is a media type G711A supported by the main callee selected by the softswitch control device;

Step 318, the foregoing caller replies to the softswitch control device with a request type acknowledgement (RequestModeAck) message;

Step 319: The calling party and the softswitch control device respectively close the voice media channel opened by the party; Step 320: The caller and the softswitch control device play a new voice media channel, wherein the media type is G711A. At this time, the caller has obtained the called media, and may send an RTP voice packet to the called party.

Step 321 to step 329 are the same as step 119 to step 127, and the called media is switched from the fake media to the calling party;

Step 330: The above-mentioned calling party is called.

The above is a detailed description of the working principle of the present invention, but this is only a visual example for the purpose of understanding and should not be construed as limiting the scope of the invention. Also, various possible equivalents and substitutions may be made in accordance with the description of the technical solutions of the present invention and the preferred embodiments thereof, and all such changes or substitutions are intended to fall within the scope of the appended claims.

Claims

Rights request

A method for implementing media switching in a voice service of the H.323 protocol, which is applicable to a caller of a fast call type, wherein the media switching process is initiated by a softswitch control device, and the type of media switch is voice media. And the switched terminal is an H.323 terminal, and the method includes the following steps:

Step 1: The calling party sends a setup message with the calling media to the softswitch control device. Step 2: The softswitch control device constructs the fake media, and sends a setup message with the fake media to the called party.

Step 3: The softswitch control device sends a ringing (alerting) message without media and a connection message of the media with the media server to the calling party by using the real-time transmission protocol, and placing the calling tone to the calling party through the real-time transmission protocol. ;

Step 7: The softswitch control device switches the calling media to the called party by using H.245 media control signaling.

Step 8: The softswitch control device sends the above called media through H.245 media control signaling. The body switches to the above caller.

2. The method of claim 1 wherein

The foregoing calling media includes at least a media type supported by the calling party, a calling media internet protocol address, and a calling media port number information;

The media type of the fake media is the same as the media type supported by the calling party, and the fake media internet protocol address is an unreachable internet protocol address, and the fake media port number is optional;

The media of the media server includes at least a ring back tone media and a prompt tone medium;

The foregoing media negotiation operation through the H.245 process includes at least a master-slave determination operation, a capability exchange operation, and an open media channel operation;

The above call tone includes at least a color ring tone and a prompt tone;

The above called media includes at least the media type supported by the called party, the called media internet protocol address, and the called media port number information.

The method according to claim 2, wherein in the step 6, the media exchange between the softswitch control device and the called party through the H.245 process is performed by using the fake media and the called media. Negotiation.

4. The method according to claim 3, characterized in that the following steps are performed before performing the above step 7:

The method according to claim 3, wherein when the called type is fast type, the following steps are further performed before the step 8 is performed - the called party and the softswitch control device sequentially perform the two-way master-slave Determine and ability to pay In addition, both the called party and the softswitch control device can receive the confirmation message of the other party.

The method according to claim 1 or 4, characterized in that the above step 7 mainly comprises the following steps:

Step 701: The softswitch control device sends a request type (RequestMode) message with the switched media type to the calling party.

Step 703: The foregoing calling party and the softswitch control device close the respective open media channels by using a two-way CloseLogicaiChannei message and a CloseLogicalChannelAck message;

Step 704: The foregoing calling party and the softswitch control device open the required media channel by using a bidirectional OpenLogicalChannd message and an OpenLogicalChamelAck message.

7. The method according to claim 1 or 5, wherein the step 8 comprises the following steps:

Step 802: After receiving the terminal capacity setting (NerminalCapabilitySetNULL) message, the called terminal returns a terminal capability setting confirmation (TerminalCapabilitySetAck) message to the softswitch control device;

Step 803: The above called party and the softswitch control device are confirmed by a bidirectional closed logical channel (CloseLogicalOiannel) message and a closed logical channel (CloseLogicalChannelAck) The message closes the respective open media channel;

Step 804: The softswitch control device receives the terminal capability setting confirmation (TerminalCapabilitySetAck) message, and confirms that the media channel is completely closed, and sends a non-empty terminal capability setting (TerminalCapabilitySet) with the switched media type to the called party. ) message

Step 807: The above called party and the above softswitch control device open the logical channel through two directions

The (OpenLogicalChannel) message and the Open Logical Channel Confirmation (OpenLogicalChannelAck) message open the desired media channel. '

8. The method according to claim 6, wherein the softswitch control device is capable of adopting a matching media switching procedure for different switched terminal types or different switched terminal nodes.

9. The method according to claim 7, wherein the softswitch control device is capable of adopting a matching media switching procedure for different switched terminal types or different switched terminal nodes.

10. The method according to claim 1, wherein the other media switching process can be initiated by using another intelligent service control device instead of the softswitch control device.

A method for implementing media switching in a voice service of the H.323 protocol, which is applicable to a calling party of a slow call type, wherein the media switching process is initiated by a softswitch control device, and the type of media switching is voice. The media, and the switched terminal is an H.323 terminal, the method includes the following steps:

Step 1: The calling party sends a setup message without the calling media to the softswitch control device. Step 2: The softswitch control device sends a setup message without the media to the called party; Step 3: The above soft The switching control device transmits a ringing message with no media and a connect message of the media without the media server by forwarding to the above-mentioned calling party;

Step 4: The foregoing calling party and the softswitch control device perform media negotiation through the H.245 process, and the calling party obtains the media of the media server and listens to the calling tone through the real-time transmission protocol.

Step 5: The called party picks up the phone, and sends a connect message without the called media to the softswitch control device.

Step 6: The softswitch control device constructs a fake medium;

12. The method of claim 11 wherein

The above-mentioned calling media includes at least a media type supported by the calling party and a calling media internet protocol address. And the calling media port number information;

The media types of the above-mentioned fake media include various commonly used media types, and the fake media internet protocol address is an unreachable internet protocol address, and the fake media port number is optional;

The foregoing operations of media negotiation through the H.245 process include at least a master-slave determination operation, a capability exchange operation, and an open media channel operation;

The above call tone includes at least a color ring tone and a prompt tone;

The method according to claim 12, wherein in the step 7, the media exchange between the softswitch control device and the called party through the H.245 process is performed by using the fake media and the called media. Negotiation.

14. The method of claim 11 wherein said step 8 comprises the steps of:

Step 803: The foregoing calling party and the softswitch control device close the respective media channels by using a two-way CloseLogicalChannel message and a CloseLogicalChannelAck message;

Step 804: The foregoing calling party and the softswitch control device open the logical channel through two directions The (OpenLogicalChannel) message and the Open Logical Channel Confirmation (OpenLogicalOiannelAck) message open the desired media channel.

15. The method of claim 11 wherein said step 9 comprises the steps of:

Step 901: The softswitch control device sets an empty capability to the called terminal.

(TerminalCapabilitySetNULL) message;

Step 902: After the called party receives the above-mentioned terminal capability setting (TeraiinalCapabilitySetNULL) message, it returns a terminal capability setting confirmation (TeraiinalCapabilitySetAck) message to the softswitch control device;

Step 903: The above called party and the above softswitch control device close the logical channel through two directions

Step 904: The softswitch control device receives the terminal capability setting confirmation (TeraiinalCapabilitySetAck) message, and confirms that the media channel is completely closed, and sends the non-empty terminal capability setting with the switched media type to the called party (Tei 'minalCapabilitySet) message;

Step 905: After receiving the foregoing non-empty terminal capability setting (Terminal CapabilitySet) message, the called party completes the two-way capability exchange process with the softswitch control device, and returns a non-empty terminal capability setting confirmation to the softswitch control device ( TeraiinalCapabilitySetAck) message; Step 906: After receiving the non-empty terminal capability setting 1A (TferminaiCapabilitySetAck) message of the called response, the softswitch control device initiates a bidirectional master-slave determination and capability exchange operation with the called party; Step 907: The above called party and the softswitch control device open the required media channel by bidirectional OpenLogical Channel (OpenLogicalChannel) message and OpenLogical ChannelAck message.

The method according to claim 14 or 15, wherein the softswitch control device is capable of adopting a matching media switching procedure for different switched terminal types or different switched terminal nodes.

The method according to claim 11, characterized in that the other intelligent service control device can be used to initiate the media switching process instead of the softswitch control device.