CN101997856B - Signaling message interaction method and application server - Google Patents

Abstract

The invention discloses a signaling message interaction method and an application server. The method comprises the following steps: the application server receives a first message from a calling party and a second message from the called party, wherein the first message carries first media transmitted to the called party, the second message carries second media transmitted to the calling party, and the first media are different from the second media; the application server judges the type of the first media; and the first media are processed according to the type of the first media. The invention can prevent media negotiation abnormality in the early stage of conversation/formal conversation when the media carry out transmission and negotiation simultaneously.

Description

Interaction method of signaling message and application server

technical field

The present invention relates to the communication field, in particular, to a method for interacting with signaling messages and an application server.

Background technique

IP Multimedia Subsystem (IP Multimedia Subsystem, referred to as IMS) is a network architecture defined by the Third Generation Partner Ship Project (3GPP) from the 3G core network to the all-IP network. A communication system composed of service control equipment, user database, and network interworking equipment is superimposed on it to provide IP multimedia services.

In the IMS system, the control layer and the service layer are separated. Specifically, the control layer does not provide specific services, but is only responsible for providing the necessary control functions such as triggering, routing, and charging to the service layer. The control function of the control layer is completed by a call session control function (Call Session Control Function, referred to as CSCF). CSCF is divided into Proxy Call Session Control Function (P-CSCF for short), Interrogating Call Session Control Function (Interrogating Call Session Control Function, I-CSCF for short) and Serving Call Session Control Function (Serving Call Session Control Function). Function, referred to as S-CSCF) three types. The business layer consists of a series of Application Servers (AS for short), which can provide specific business services. The AS can be an independent entity or exist in the S-CSCF. The S-CSCF controls service triggering according to the user's subscription information, and invokes services on the AS to realize specific service functions. The AS and the S-CSCF may be collectively referred to as Server Equipment (SE for short). The end-to-end device in the session is called User Equipment (UE for short), and is responsible for interacting with the user. Each functional entity in the IMS uses the Session Initiation Protocol (SIP for short) for communication.

SIP is a signaling control protocol at the application layer for creating, modifying and releasing sessions of one or more participants. In order to describe the load and characteristics of the message content, SIP uses the Internet Session Description Protocol (SDP) to describe the characteristics of the terminal device. The SDP protocol can transfer media flow information in a media session, allowing the receiver of the session description to participate in the session. In the media session, it can be divided into early session (Early Session) and formal session (Regular Session, referred to as Session), and the media used are early media (Early Media), such as ring back tone, ring tone and waiting tone, etc. and call media (Regular Media).

The following describes the implementation of Early Media in detail. RFC3960 defines two implementations for Early Media, namely the Gateway mode and the ApplicationServer mode. Specifically:

The Gateway mode completes the Early Media interaction by establishing an Early Session before the final response. Usually, the media interaction can be achieved by temporarily and reliably responding to PRACK and UPDATE. However, the Gateway mode may have Media Clipping during Forking. Therefore, in order to achieve the traditional For the effect of the PSTN network, the calling end needs to have a complex local playback strategy. Except for the case where the calling end cannot distinguish between Early and Regular media, the Application server mode should be preferred.

The Application Server mode completes media interaction by establishing an Early Session session separated from the Session session between the User Agent Server (UAS for short) and the User Agent Client (UAC for short). Carry out media negotiation with the Session separately, switch to the Session media when the Session media arrives, or switch to the Session media when receiving 200 OK on the signaling, so as to ensure that the Session media will not be lost. Application Server mode is to carry out Early Session and Session media negotiation under the same Dialog condition. From the perspective of the terminal side, negotiation and resource reservation are performed on the Early Session and Session media ports respectively. From the perspective of the AS side , under the same Dialog, different transaction signaling messages can be used to carry two pieces of media respectively for transmission and negotiation. However, if the SIP protocol stack does not support parallel multi-transactions, that is, the SIP protocol stack can only process one transaction at the same time, the interaction of signaling messages carrying two pieces of media is prone to conflicts, resulting in media negotiation exceptions.

To sum up, in the related art, when the SIP protocol stack does not support parallel multi-transactions, the interaction of signaling messages carrying two pieces of media is likely to cause conflicts and lead to abnormal media negotiation, and no effective solution has been proposed yet.

Contents of the invention

The present invention is proposed aiming at the problem existing in the related art that the interaction of signaling messages carrying two pieces of media is prone to conflict and lead to abnormal media negotiation when the SIP protocol stack does not support parallel multi-transactions. The purpose is to provide a signaling message interaction method and an application server to solve at least one of the above problems.

In order to achieve the above object, according to one aspect of the present invention, a signaling message interaction method is provided.

The signaling message interaction method according to the present invention includes: the application server receives a first message from the calling party and a second message from the called party, wherein the first message carries the first media sent to the called party, and the second message It carries the second media sent to the caller, and the first media is different from the second media; the application server judges the type of the first media; and processes the first media according to the type of the first media.

Preferably, the application server judging the type of the first media includes: judging that the first media is response-type media or providing-type media.

Preferably, processing the first media according to the type of the first media includes: if it is judged that the first media is response-type media, the application server caches the first media; In this case, the application server returns the first media.

Preferably, the application server rolling back the first media includes: the application server sending a rollback message carrying information indicating a waiting time to the first medium, wherein the waiting time is the time when the calling party is allowed to initiate a signaling request message to the application server again Minimum wait time.

Preferably, after the first media is processed according to the type of the first media, the above method further includes: the application server sends a message carrying the second media to the caller.

Preferably, in the case that the first media is response media, after the application server sends the message carrying the second media to the calling party, the above method further includes: the application server sends the message carrying the first media to the called party.

Preferably, the first media is formal conversation media, and the second media is early conversation media; or, the first media is early conversation media, and the second media is formal conversation media.

In order to achieve the above purpose, according to another aspect of the present invention, an application server is provided.

The application server according to the present invention includes: a receiving module, configured to receive a first message from the calling party and a second message from the called party, wherein the first message carries the first media sent to the called party, and the second message carries There is a second media sent to the caller, and the first media is different from the second media; a judging module is used to judge the type of the first media; a processing module is used to process the first media according to the type of the first media.

Preferably, the processing module includes: a first processing submodule, configured to cache the first media when the first media is a response type of media; a second processing submodule, configured to cache the first media when the first media is a provision type of media Fallback to the first medium.

Preferably, the application server further includes: a sending module, configured to send a message carrying the second media to the caller after the processing module processes the first media.

Through the present invention, the early session/formal session media from the calling party is cached or rolled back, which solves the problem that the interaction of signaling messages carrying two pieces of media is prone to conflict when the SIP protocol stack does not support parallel multi-transactions The problem of causing media negotiation exceptions can prevent the occurrence of media negotiation exceptions when the early session/formal session media is transmitted and negotiated at the same time.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

FIG. 1 is a flowchart of a signaling message interaction method according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an application scenario of a signaling message interaction method according to an example of the present invention;

FIG. 3 is a signaling flow chart of a signaling message interaction method according to an example of the present invention;

FIG. 4 is a structural block diagram of an application server according to an embodiment of the present invention;

Fig. 5 is a structural block diagram of an application server processing module according to an embodiment of the present invention.

Detailed ways

Functional Overview

Considering the problems existing in the prior art, the embodiment of the present invention provides a signaling message interaction scheme, which is used to control the signaling of the media negotiation of the terminal on the AS side so as to solve the abnormal conflict in the negotiation. The processing principle is as follows: the application server receives the first message from the calling party and the second message from the called party, wherein the first message carries the first media sent to the called party, and the second message carries the media sent to the calling party The second media is different from the first media; the application server judges the type of the first media; and processes the first media according to the type of the first media. This solution makes comprehensive decisions and judgments based on whether there are Session/Early Session called media that need to be sent to the calling party and the Early Session/Session calling media sent by the calling party, and controls, so that the forwarding AS can use the Application Server In this mode, the Early Session and Session media are negotiated separately to control signaling to avoid signaling conflicts.

Hereinafter, the present invention will be described in detail with reference to the drawings and examples. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

method embodiment

According to an embodiment of the present invention, a signaling message interaction method is provided. FIG. 1 is a flow chart of a signaling message interaction method according to an embodiment of the present invention. As shown in FIG. 1, the method includes the following steps S102 to S106:

Step S102, the application server receives a first message from the calling party and a second message from the called party, wherein the first message carries the first media sent to the called party, and the second message carries the second media sent to the calling party. The media, the first media and the second media are not the same, specifically, the first media is the formal session media and the second media is the early session media, or the first media is the early session media and the second media is the formal session media, for example , in practical applications, the AS judges that there is a Session/Early Session called media that needs to be sent to the calling party, and at the same time judges that there is an Early Session/Session calling media sent by the calling party. In practical applications, the above-mentioned first message and the second message may be SIP messages, that is, the above-mentioned first message and the second message may specifically be the first SIP message and the second SIP message, or other SIP messages capable of carrying the above-mentioned media. message, which is not limited in this embodiment of the present invention.

Step S104, the application server judges the type of the first media, wherein the type of the first media can be answer media or offer media, that is, the AS judges whether the Early Session/Session calling media sent by the caller is Answer media or Offer media.

Step S106, process the first media according to the type of the first media. Specifically, if the application server judges that the first media is response media, the application server caches the first media; or when the application server judges that the first media is In the case where the type of is the provided media, the application server rolls back the first media, and the application server rolls back the first media specifically: the application server sends a rollback message carrying information indicating the waiting time to the first media, wherein the waiting The time is the minimum waiting time for the caller to be allowed to initiate a signaling request message to the application server again. After processing the first media according to the type of the first media, the application server sends a message carrying the second media to the caller. In practical applications, if the AS judges that the Early Session/Session calling media sent by the calling party is Answer media, it will cache the Answer calling media, and then send the Session/Early Session called media through an appropriate SIP transaction signaling message To the caller, to meet the requirements of negotiating two pieces of media at the same time, or, if the AS judges that the EarlySession/Session media sent by the caller is Offer media, it will send a 500 message to the caller, and then carry it through the appropriate SIP transaction signaling message Session/Early Session The called media is sent to the calling party to meet the requirement of negotiating two media at the same time. The above 500 message contains the Retry-After header, and the time value is an optional value from 0 to 10S. During the time interval specified by the Retry-After field, the calling terminal should not send any other signaling requests to the application server AS; When the time indicated by the Retry-After header arrives, the calling terminal resends the corresponding signaling request carrying the media to the AS, and the sending of the signaling at this time depends on the decision of the terminal side.

Further, when the type of the first media is response media, after the application server sends the initial session protocol signaling message carrying the second media to the calling party, the application server sends the message carrying the first media to the called party. information.

The implementation process of the embodiment of the present invention will be described in detail below with reference to examples.

Fig. 2 is a schematic diagram of the application scenario of the interaction method of signaling messages according to the example of the present invention, and Fig. 3 is a signaling flowchart of the interaction method of signaling messages according to the example of the present invention, specifically in the case of a non-parallel multi-transaction SIP protocol stack Use the Application Server pattern to complete the call process. Based on the scenario shown in FIG. 2 and in combination with FIG. 3 , a specific example of the forwarding on no answer service will be described below, and the method provided by the embodiment of the present invention will be described by taking this as an example. It should be noted that, in FIG. 3 , forwarding ASs of user equipment B and user equipment C and related messages are omitted.

1. User equipment A calls B and initiates a session request (session) to its CSCF;

2. The CSCF of user equipment A initiates a session request (session) to the CSCF for B;

3. The CSCF of user equipment B initiates a session request (session) to the forwarding AS;

4. The forwarding AS initiates a session request (session) to the CSCF of the user equipment B;

5. The CSCF of user equipment B initiates a session 180 response (earlysession) to the forward AS;

6. The forwarding AS initiates a session 180 response (earlysession) to the CSCF of user equipment B;

7. The CSCF of user equipment B initiates a session 180 response (early session) to the CSCF of user equipment A;

8. The CSCF of user equipment A initiates a session 180 response (earlysession) to user equipment A;

9. User equipment A initiates a session prack request (earlysession) to the CSCF of user equipment A;

10. The CSCF of user equipment A initiates a session prack request (early session) to the CSCF of user equipment B;

11. The CSCF of user equipment B initiates a session prack request (earlysession) to the forward AS;

12. The forwarding AS initiates a session prack request (earlysession) to the CSCF of user equipment B;

13. After the forwarding AS does not respond overtime, initiate a session request (session) to the CSCF of user equipment B, and forward to C;

14. The CSCF of user equipment B initiates a session request (session) to the CSCF of user equipment C;

15. The CSCF of the user equipment C finally initiates a session request (session) to the user equipment C;

16. The user equipment C initiates a session 183 response (earlysession, session) to the CSCF of the user equipment C;

17. The CSCF of user equipment C initiates a session 183 response (early session, session) to the CSCF of user equipment B;

18. The CSCF of user equipment B initiates a session 183 response (early session, session) to the forwarding AS of user equipment B;

19. After Early-Session and Session perform media negotiation respectively, the forwarding AS of user equipment B initiates a session update request (earlysession) to the CSCF of user equipment B;

20. The CSCF of user equipment B initiates a session update request (early session) to the CSCF of user equipment A, and the forwarding AS (B) forwards the Early-Session Offer media to A through the session request message;

21. The CSCF of user equipment A initiates a session update request (early session) to user equipment A;

22. User equipment A initiates a session 200OK response (early session) to the CSCF of user equipment A;

23. The CSCF of user equipment A initiates a session 200OK response (early session) to user equipment A;

24. The CSCF of user equipment B initiates a session 200OK response (early session) to the forwarding AS of user equipment B, that is, initiates an Answer response message of the Early-Session to the forwarding AS (B), and the AS caches the calling Answer media;

25. User equipment A initiates a session update request (early session) to the CSCF of user equipment A;

26. The CSCF of user equipment A initiates a session update request (early session) to the CSCF of user equipment B;

27. The CSCF of user equipment B initiates a session update request (earlysession) to the forwarding AS, specifically, initiates an Early-Session Offer request message to the forwarding AS (B);

28. The forwarding AS of user equipment B sends a 500 (Retry-After) message to the CSCF of user equipment B to roll back the above Offer request message;

29. The CSCF of user equipment B initiates a 500 (Retry-After) message to the CSCF of user equipment A;

30. The CSCF of user equipment A initiates a 500 (Retry-After) message to user equipment A;

31. The forwarding AS of user equipment B initiates a session 183 response (session) to the CSCF of user equipment B;

32. The CSCF of user equipment B initiates a session 183 response (session) to the CSCF of user equipment A;

33. The CSCF of user equipment A initiates a session 183 response (session) to user equipment A.

The above step 31 to step 33 is that the forwarding AS of the user equipment B forwards the Answer media of the Session to the user equipment A through the session response message.

Moreover, within the Retry-After time interval of the calling terminal A, the UE does not send a request to the original server.

Device embodiment

According to an embodiment of the present invention, an application server is provided. Fig. 4 is a structural block diagram of an application server according to an embodiment of the present invention. As shown in FIG. 4, the above-mentioned application server includes: a receiving module 42, configured to receive a first message from the calling party and a second message from the called party, wherein the first message carries the first media sent to the called party, The second message carries the second media sent to the caller, and the first media is different from the second media; the judging module 44 is connected to the receiving module 42 for judging the type of the first media; the processing module 46 is connected to the judging module 44, configured to process the first media according to the type of the first media.

Fig. 5 is a structural block diagram of an application server processing module according to an embodiment of the present invention. As shown in Figure 5, the processing module includes: a first processing sub-module 52, which is used to buffer the first media when the first media is a response type media; a second processing sub-module 54, which is used to provide Fallback to first media in case of class media.

Preferably, the application server may further include: a sending module, configured to send a message carrying the second media to the caller after the processing module processes the first media.

The signaling message interaction solution provided by the embodiment of the present invention can use the media negotiation method of the Application Server mode at the same time under the condition that the SIP protocol stack does not support parallel multi-transactions, and in the case of simultaneous transmission and negotiation of early session/formal session media It can prevent the occurrence of abnormal media negotiation.

Obviously, those skilled in the art should understand that each module or each step of the above-mentioned present invention can be realized by a general-purpose computing device, and they can be concentrated on a single computing device, or distributed in a network formed by multiple computing devices Optionally, they can be implemented with program codes executable by a computing device, so that they can be stored in a storage device and executed by a computing device, or they can be made into individual integrated circuit modules, or they can be integrated into Multiple modules or steps are fabricated into a single integrated circuit module to realize. As such, the present invention is not limited to any specific combination of hardware and software.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. A method for interacting with signaling messages, characterized in that the method comprises: The application server receives a first message from the calling party and a second message from the called party, wherein the first message carries the first media sent to the called party, and the second message carries the media sent to the called party. The second media of the caller, the first media is different from the second media; the first media is formal session media, and the second media is early session media; or, the first media is early session media media, the second media being formal conversational media; The application server determines the type of the first media; processing the first media according to the type of the first media, Wherein, the application server judging the type of the first media includes: judging that the first media is response-type media or providing-type media, and if it is determined that the first media is the response-type media, The application server caches the first media; or in a case where it is determined that the first media is the provided type of media, the application server rolls back the first media. 2. The method according to claim 1, wherein the application server rolling back the first media comprises: The application server sends a rollback message carrying information indicating a waiting time to the first medium, where the waiting time is the shortest waiting time for the calling party to be allowed to initiate a signaling request message to the application server again time. 3. The method according to claim 1, wherein, after processing the first media according to the type of the first media, the method further comprises: The application server sends a message carrying the second media to the caller. 4. The method according to claim 3, wherein when the first media is the response type media, when the application server sends the caller the message carrying the second media After the message, the method also includes: The application server sends a message carrying the first media to the called party. 5. An application server, characterized in that, comprising: A receiving module, configured to receive a first message from the calling party and a second message from the called party, wherein the first message carries the first media sent to the called party, and the second message carries the To the second media of the caller, the first media is different from the second media; the first media is formal session media, and the second media is early session media; or, the first media is early conversational media, and the second media is formal conversational media; a judging module, configured to judge the type of the first media; A processing module, configured to process the first media according to the type of the first media, wherein the processing module includes: A first processing submodule, configured to cache the first media when the first media is response media; The second processing submodule is configured to roll back the first media when the first media is a provided type of media. 6. The application server according to claim 5, further comprising: A sending module, configured to send a message carrying the second media to the caller after the processing module processes the first media.