CN1266885C - Method for realizing monitoring based on soft switch - Google Patents

Abstract

The invention discloses a method for realizing monitoring based on softswitch. The method includes: a target user establishes a call, and an MGC and a monitoring system establish a call through the interaction of SIP protocol format messages; MG reports the communication content of the target user to the monitoring system. According to the method proposed in the present invention, the standard SIP protocol is adopted as the communication standard between the monitoring system and the MGC, and the simplified process based on the SIP protocol is also defined in the present invention; the MG is also specified in the present invention to transmit the target to the monitoring system The bearer mode of user communication content, through the use of mature and standardized protocols, makes the legal interception based on softswitches have good standardization and scalability, makes the interception interface universal, and does not need to modify the switching equipment, which is very conducive to subsequent fixed communications The integration of network switching equipment and mobile communication network switching equipment.

Description

A Method of Monitoring Based on Softswitch

technical field

The invention relates to monitoring technology, in particular to a method for realizing monitoring based on softswitch.

Background technique

With the development of communication technology, traditional switching equipment has gradually evolved into a framework that separates bearer and control, and voice services have gradually evolved from traditional time-division multiplexing (TDM) circuit-based voice to bearer on Internet Protocol (IP) networks. The packet voice, the communication content is transmitted on the IP network in the form of Real-Time Transport Protocol (RTP, Real-Time Transport Protocol) flow, and the communication content can be voice, multimedia services, etc. In this way, Softswitch (Softswitch) technology appeared.

Softswitch technology is the core technology to realize the new generation of voice communication and multimedia and data interaction. Softswitch technology embodies the idea of separation of control/service and bearer. As a control entity, the softswitch completes functions such as call connection, service control, and user management, while the transmission of service media streams is completed by the IP network.

Media Gateway Controller (MGC, Media Gateway Controller) is the core device in the softswitch technology. It is located at the control layer of the next-generation network and mainly completes functions such as call control, authentication and authorization, billing, service provision, and interconnection. All services require a media gateway (MG, MediaGateway) to be implemented under the control of the MGC. The MG can convert the media format in one network into the media format required by another network, and the MGC controls the establishment and release of the MG connection according to the received signaling.

With the occurrence of more and more terrorist incidents and vicious crimes, the issue of national security has become more and more important. At present, as an important part of national security measures, legal interception of telecommunications has been increasingly valued by the international community, and many countries have put forward requirements in the form of legislation. According to this law, state agencies can monitor and intercept the phone calls, faxes and e-mails of designated target users, such as criminal suspects. At the same time, service providers are also required to provide enforcement agencies with the means to monitor their data and voice lines.

Since the independent core packet network technology has not matured for a long time, and the softswitch technology has not yet been commercialized on a large scale, the relevant agreement only gives a general description of the monitoring based on the softswitch, and does not give the implementation method and specific implementation process. For the legal interception based on softswitch, especially the communication mode adopted between the switching device and the interception system, there is still no specific and general solution, and each company mainly uses a private protocol as a temporary solution. , to realize the communication between the switching device and the monitoring system.

In this way, in the existing monitoring based on the softswitch, the call control part can only use a private protocol, for example, a custom tunnel mechanism, and the communication content of the target user is transmitted through a custom tunnel, which will limit the expansion of the subsequent monitoring function. As a result, the monitoring interface varies greatly and does not have a unified standard, which makes the adaptability and inheritance of the monitoring interface between the monitoring system and the switching device very poor. At the same time, in order for the switching device to provide the monitoring function to the monitoring system, it is necessary to A large number of non-standardized changes are made to the switching equipment, so that the monitoring based on the softswitch is not standardized.

Contents of the invention

In view of this, the object of the present invention is to provide a method for realizing interception based on softswitch, so that the lawful interception realized based on softswitch has good standardization and expansibility.

In order to achieve the above-mentioned purpose, the present invention provides a kind of method that realizes monitoring based on softswitch, presets the target user that is monitored, and this method comprises the following steps:

A. When the monitored target user establishes a call, the MGC and the monitoring system establish the call through the interaction of messages in the SIP protocol format;

B. The MG reports the communication content of the target user to the monitoring system.

The MGC described in the step A and the monitoring system establish a call through the interaction of the SIP protocol format message, including the following steps:

A1. The MGC sends an invitation to join the call message in the SIP protocol format to the monitoring system;

A2. After receiving the invitation to join the call message, the monitoring system returns a call establishment response to the MGC;

A3. After receiving the call establishment response, the MGC returns a response message to the monitoring system.

The SDP description of the MG is carried in the invitation to join the call message described in step A1;

The call establishment response mentioned in step A2 carries the SDP negotiation result.

The call invitation message in step A1 carries a call association identifier for associating the target user's communication content with the activity event.

The call association identifier is carried in the extension header of the invitation to join call message mentioned in step A1.

The invitation to join the call message in step A1 carries the MGC ID, or the monitoring system ID, or the calling number, or the called number, or a combination of one or more of the above.

The step B is: the MG reports the communication content of the target user to the monitoring system through the standard RTP stream.

The RTP stream is carried over an IP network.

The RTP stream carries the transmission direction of the communication content of the target user.

The method further includes:

C1. The MGC and the monitoring system modify the established call through the interaction of messages in the SIP protocol format.

Said step C1 comprises the following steps:

C11. The MGC sends a call modification message in the SIP protocol format to the monitoring system, and the call attribute is carried in the call modification message;

C12. After receiving the invitation to join the call message, the monitoring system modifies the established call according to the call attribute, and then returns a call establishment response to the MGC;

C13. After receiving the call establishment response, the MGC returns a response message to the monitoring system.

The method further includes:

C2, the MGC and the monitoring system release the call through the interaction of messages in the SIP protocol format.

Described step C2 comprises the following steps:

C21. The target user releases the call, and the MGC sends a call termination message in the SIP protocol format to the monitoring system;

C22. After receiving the call termination message, the monitoring system returns a call establishment response to the MGC, and then releases the established call.

The method further includes: canceling setting of the monitored target user.

According to the method proposed in the present invention, the standard SIP protocol is adopted as the communication standard between the monitoring system and the MGC, and the simplified process based on the SIP protocol is also defined in the present invention; the MG is also specified in the present invention to transmit the target to the monitoring system The bearer mode of user communication content, through the use of mature and standardized protocols, makes the legal interception based on softswitches have good standardization and scalability, makes the interception interface universal, and does not need to modify the switching equipment, which is very conducive to subsequent fixed communications The integration of network switching equipment and mobile communication network switching equipment.

Description of drawings

Fig. 1 is the schematic diagram of the realization scheme of the present invention;

Figure 2 is a flow chart of setting target users;

Figure 3 is a flow chart of establishing a call between the MGC and the monitoring system;

Fig. 4 is the flow chart of calling for modifying the MGC and monitoring system;

FIG. 5 is a schematic diagram of the communication content of the target user transmitted by the MG to the monitoring system;

Fig. 6 is the flow chart of MGC and monitoring system release call;

Fig. 7 is a flow chart of querying target users;

Fig. 8 is a flow chart of canceling a target user.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

Fig. 1 is the schematic diagram of the realization scheme of the present invention, as shown in Fig. 1, in the present invention, after setting the monitored target user, when the target user sets up a call, utilize standard session initiation protocol (SIP, SessionInitiated Protocol) to set up MGC and After the call between the monitoring systems is established, the MG transmits the communication content of the target user to the monitoring system in the format of RTP flow according to the control of the MGC after the call is established, and the invention defines a simplified process based on SIP, so that the softswitch-based Lawful interception has good standardization and scalability.

Figure 2 is a flow chart of setting target users. As shown in Figure 2, the implementation process of setting target users includes the following steps:

Step 201: the monitoring system sends a target user setting request to the MGC, requesting the MGC to set a target user. The target user setting request can carry one user ID, and can also carry multiple user IDs; in addition, the target user setting request can also carry the monitoring attribute corresponding to the target user, requiring the MGC to set the target user, and at the same time Set monitoring attributes corresponding to the target user, for example, the monitoring system requires the MGC to only monitor the video conference of the target user.

Step 202: After receiving the target user setting request, the MGC sets the corresponding user as the monitored target user, adds the corresponding user to the target user list, and then returns a target user setting response to the monitoring system, notifying the monitoring system that the corresponding user has been Set as the target user to be monitored.

After the MGC sets the target user, when a user establishes a call, the MGC judges whether the user belongs to the target user list. If so, the MGC establishes a call with the monitoring system while establishing a call for the target user; The user establishes a call.

Figure 3 is a flow chart of establishing a call between the MGC and the monitoring system. As shown in Figure 3, when the target user sets up a call, the MGC will establish a call with the monitoring system, and the implementation process of establishing a call between the MGC and the monitoring system includes the following steps:

Step 301: The MGC sends an invitation to join the call message (INVITE) to the monitoring system. The INVITE carries parameters required for monitoring, such as MGC ID, monitoring system ID, calling number, called number, authentication parameters, and MG session description Description of the protocol (SDP, Session Description Protocol), etc. At the same time, an extended header is added to the invitation to join the call message, which is used to transfer the call association identifier (CCC_ID), and the CCC_ID is used to associate the communication content and activity events of the target user. The syntax of the extension header can be in the following format:

X-LIC-CCCID="X-LIC-CCCID" HCOLON 1*DIGIT.

Step 302: After receiving the INVITE, the monitoring system returns a 200 OK response message to the MGC, and the 200 OK carries the SDP negotiation result.

Step 303: After receiving the 200 OK, the MGC returns an ACK response message to the monitoring system, notifying the monitoring system that it has received its response to the INVITE. In this way, the MGC establishes a call with the monitoring system.

The MGC may also establish a call with the monitoring system when the target user establishes a call related to the monitoring property according to the monitoring attribute of the target user set by the monitoring system.

Fig. 4 is the flow diagram of modifying the call between the MGC and the monitoring system. As shown in Fig. 4, when the target user modifies the calling, the MGC will modify the calling with the monitoring system, and the implementation process of modifying the calling between the MGC and the monitoring system includes the following steps:

Step 401: The MGC modifies the established call, and then sends a modify call message (re-INVITE) to the monitoring system, and the re-INVITE carries call attributes.

Step 402: After receiving the re-INVITE, the monitoring system modifies the established call according to the call attribute, and then returns 200 OK to the MGC, notifying the MGC that the call has been successfully modified.

Step 403: After receiving the 200 OK, the MGC returns an ACK to the monitoring system, notifying the monitoring system that it has received its response to the re-INVITE. In this way, the call between the MGC and the monitoring system is successfully modified.

Figure 5 is a schematic diagram of the communication content of the target user transmitted by the MG to the monitoring system. As shown in Figure 5, the MG transmits the communication content of the target user to the monitoring system through the standard RTP stream, and the RTP stream transmitted by the MG to the monitoring system carries the communication content of the target user direction of transmission. The RTP stream is carried on the IP network without additional expansion, that is, it does not need to be realized through a private protocol, and it can be completely realized by using a standard protocol. In addition, in order to ensure the security of the target user's communication content, the security mechanism of the IP network link layer, such as IPSec, can be used to increase the security of the target user's communication content transmission process.

Figure 6 is a flow chart of releasing a call between the MGC and the monitoring system. As shown in Figure 6, when the target user releases the call, the MGC will release the call with the monitoring system, and the implementation process of releasing the call between the MGC and the monitoring system includes the following steps:

Step 601: The MGC sends a call termination message (BYE) to the monitoring system to notify the monitoring system to release the call.

Step 602: After receiving the BYE, the monitoring system returns 200 OK to the MGC, notifying the MGC that the BYE has been received, and then releases the call with the MGC. After receiving the 200OK, the MGC releases the call with the monitoring system.

Figure 7 is a flow chart of querying target users. As shown in Figure 7, the implementation process of querying target users includes the following steps:

Step 701: The monitoring system sends a target user query request to the MGC, requesting the MGC to provide relevant information of the target user. The target user query request can carry corresponding query parameters, such as target user list query, a target user, etc., and the default query parameter can also be set as target user list query.

Step 702: After receiving the target user query request, the MGC returns a target user query response to the monitoring system. The target user query response carries corresponding query information, for example, returns to the monitoring system according to the corresponding query parameters carried in the target user query request. A list of target users, or a user's listening attributes, etc.

Figure 8 is a flow chart of canceling a target user. As shown in Figure 8, the implementation process of canceling a target user includes the following steps:

Step 801: The monitoring system sends a target user cancellation request to the MGC, requesting the MGC to cancel the setting of the target user. The target user setting request may carry one target user or multiple target users.

Step 802: After receiving the target user cancellation request, the MGC cancels the setting of the corresponding target user, deletes the corresponding target user from the target user list, and then returns a target user cancellation response to the monitoring system, notifying the monitoring system that the corresponding target user has been canceled settings.

The target user list is stored in the MGC. When the monitoring system sets a new target user to be monitored, the MGC will add the corresponding target user to the target user list. When the monitoring system cancels the target user, the MGC will delete it from the target user list. corresponding target users.

In addition, the monitoring system can notify the MGC to delete the target user list and cancel the setting of all target users. For example, the monitoring system can notify the MGC to delete the entire target user list by sending a target user cancellation request without any parameters to the MGC.

The MGC mentioned above can be a packet switching device such as a mobile switching center server (MSC Server), a gateway mobile switching center server (GMSC Server).

In a word, the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (14)

1, a kind of method that realizes monitoring based on soft switch, it is characterized in that, preset the target user that is monitored, this method comprises the following steps: A. When the monitored target user establishes a call, the MGC and the monitoring system establish the call through the interaction of messages in the SIP protocol format; B. The MG reports the communication content of the target user to the monitoring system. 2. The method according to claim 1, characterized in that, in step A, the MGC and the monitoring system establish a call through the interaction of SIP protocol format messages, including the following steps: A1. The MGC sends an invitation to join the call message in the SIP protocol format to the monitoring system; A2. After receiving the invitation to join the call message, the monitoring system returns a call setup response to the MGC; A3. After receiving the call establishment response, the MGC returns a response message to the monitoring system. 3. The method of claim 2, wherein: The SDP description of the MG is carried in the invitation to join the call message described in step A1; The call establishment response mentioned in step A2 carries the SDP negotiation result. 4. The method according to claim 2, wherein the call invitation message in step A1 carries a call association identifier for associating the target user's communication content with the activity event. 5. The method according to claim 4, characterized in that the call association identifier is carried in the extension header of the invitation to join the call message in step A1. 6. The method according to claim 2, 3 or 4, characterized in that the message of inviting to join the call in step A1 carries the MGC ID, or monitoring system ID, or calling number, or called number, Or a combination of one or more of the above. 7. The method according to claim 1, wherein the step B is: the MG reports the communication content of the target user to the monitoring system through the RTP stream in a standard format. 8. The method according to claim 7, wherein the RTP stream is carried on an IP network. 9. The method according to claim 7, wherein the RTP stream carries the transmission direction of the communication content of the target user. 10. The method according to claim 1, further comprising: C1. The MGC and the monitoring system modify the established call through the interaction of messages in the SIP protocol format. 11. The method according to claim 10, characterized in that said step C1 comprises the following steps: C11. The MGC sends a call modification message in the SIP protocol format to the monitoring system, and the call attribute is carried in the call modification message; C12. After receiving the invitation to join the call message, the monitoring system modifies the established call according to the call attribute, and then returns a call establishment response to the MGC; C13. After receiving the call establishment response, the MGC returns a response message to the monitoring system. 12. The method according to claim 1, further comprising: C2, the MGC and the monitoring system release the call through the interaction of messages in the SIP protocol format. 13. The method according to claim 12, wherein said step C2 comprises the following steps: C21. The target user releases the call, and the MGC sends a call termination message in the SIP protocol format to the monitoring system; C22. After receiving the call termination message, the monitoring system returns a call establishment response to the MGC, and then releases the established call. 14. The method according to claim 1, further comprising: canceling the setting of the intercepted target user.

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