CN100583786C

CN100583786C - Legal listening system, method, and application server

Info

Publication number: CN100583786C
Application number: CN200710000332A
Authority: CN
Inventors: 施有铸; 郑波; 张妮
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2006-12-31
Filing date: 2007-01-12
Publication date: 2010-01-20
Anticipated expiration: 2027-01-12
Also published as: CN101212365A

Abstract

The invention relates a lawful interception system, a method and an application server. A VCC application server with voice call continuity is arranged in a service signaling routing and according to interception requirement of a VCC user service, the VCC application server controls a body with medium gateway function to be located in a medium routing; the body with the medium gateway function located in the medium routing replicates talking medium stream of the user and then outputs. That the body with the medium gateway function is controlled to be located in the medium routing can include the following situation: the VCC application server controls the body with the medium gateway function to be added in the medium routing in the establishment process of the VCC user service, or after the successful establishment of the service or in the switching process of the service; that the body with the medium gateway function is controlled to be located in the medium routing can also include the situation: the VCC application server controls the body with the medium gateway function to be continuously located in the medium routing in the switching process of the VCC user service. Though adopting the technical proposal, talking medium flow of the VCC users in diversified application scenes can be intercepted so as to ensure the integrity of the interception content as well as the continuity of the interception process.

Description

A kind of legal interception system, methods and applications server

Technical field

The present invention relates to the network communications technology field, be specifically related to a kind of legal interception system, methods and applications server.

Background technology

LI (Lawful Interception) comprises that the signaling aspect is monitored and the medium aspect is monitored.The signaling aspect is monitored the IRI (Intercept related information) that needs the output eavesdropping target, and the medium aspect is monitored the CC (Content of Communication) that needs the output eavesdropping target.

In traditional CS territory, be provided with three interfaces between the Lawful Interception law actuating equipment of communication equipment and listening center, promptly data-interface, IRI report interface and CC to report interface.ADMF is the management function entity of Lawful Interception, and ADMF is issued to communication network by data-interface with monitored data and monitors control network element (Interception Control Element).Communication network is monitored the control network element when listening to eavesdropping target movable, report interface to be reported to listening center by DF2 (2 passages are submitted functional entity) by IRI by eavesdropping target's Intercept related information, communication network is monitored the control network element when the Content of Communication that listens to the eavesdropping target is Media Stream, report interface that eavesdropping target's Content of Communication is reported listening center by CC, promptly communication network is monitored control network element duplicate media stream and is reported to listening center.

IMS (IP Multimedia Subsystem, IP Multimedia System) adopts SIP (Session InitiationProtocol, Session initiation Protocol) and the independence that inserts.IMS is a multimedia control/calling controlling platform on the PS territory, supports conversation class and non-conversation class multimedia service, for the multimedia application in future provides a general business platform.

At present, the Lawful Interception network model of IMS network as shown in Figure 1.

Among Fig. 1, the Lawful Interception network model of IMS network comprises: LEMF (Law EnforcementMonitoring Facility, judicial execution monitoring equipment), ADMF (management function of Lawful Interception) entity, DF (Delivery Function handoff functions) entity, S-CSCF (Serving Call Session ControlFunction, service call conversation control function) entity and P-CSCF (Proxy-CSCF, Proxy Call Session Control Function) entity.Wherein, LEMF entity, ADMF entity and DF entity all are positioned at law enforcement agency's side, and S-CSCF entity and P-CSCF entity are arranged in the IMS network as the control of the monitoring among IMS network element.

At Fig. 1, the specific implementation process of the Lawful Interception of IMS network is: when needs are monitored the eavesdropping target in the IMS network, that is to say when needing down-link monitoring data, the ADMF entity can be carried at the various monitored datas of law enforcement agency's side each and monitor in the indication, and the monitoring indication that will carry monitored data directly is sent to S-CSCF entity and/or P-CSCF entity in the IMS network; Wherein, include eavesdropping target's sign in the monitored data; Monitor indication and activate indication, eavesdropping target's inquiry and the indication of eavesdropping target's attribute modification etc. as the eavesdropping target.S-CSCF entity and/or P-CSCF entity are monitored the eavesdropping target according to the monitored data that carries in the monitoring indication that receives, and the eavesdropping target's that gets access to relevant monitoring content is sent to the DF entity of law enforcement agency's side, and by the DF entity transmission to LEMF.

At present, communication circle has proposed the notion of VCC (continuous voice call), because the Lawful Interception in the present specification relates to the VCC technology, below the VCC technology is simply introduced.

The VCC business is the IMS application service of user's home domain of contracting, the user who has IMS territory and CS territory access capability simultaneously is called as VCC user, audio call can keep not being interrupted when VCC user changed between CS territory and IMS territory, and VCC user is not connected the influence of variation to the experience of speech business.

For realizing the two-way switching of audio call between CS territory and IMS territory, the audio call that all VCC users initiate or receive all must anchor in the IMS territory of this VCC user attaching on the AS (application server) with territory switching control function, realizes that by this AS the VCC user's voice calls out the continuous voice call when switching between IMS territory and CS territory.Above-mentioned AS can call the AS for VCC.VCCAS also should have the territory selection function.

When VCC user switches to another territory and proceeds audio call according to the measurement of wireless environment decision needs, must guarantee this moment VCC user registered and VCC user has different signs in the IMS territory with the CS territory in two territories, register with different signs.VCC user is being switched the specific called number initiation audio call of purpose territory use, and this audio call is routed to provides the AS of territory handoff functionality place to handle in the network.AS according to VCC user after the incidence relation between IMS territory and the CS domain identifier identifies the session that this audio call is grappling, remote subscriber in acting on behalf of this VCC user and calling out carries out SDP (Session Description Protocol, Session Description Protocol) again to be consulted.After SDP negotiation was finished, AS set up new access leg (Access leg) for this VCC user, then, discharged in the handover source territory and the calling between VCC user, finished handoff procedure.

Present legal listening method can not be monitored all business that VCC user is taken place, as LEA (Law Enforcement Agency, judicial execution agency is a listening center) issue snoop command in the IMS territory of VCC user attaching, then can only listen to the miscellaneous service of VCC user in the IMS territory, can't listen to the business of VCC user in the CS territory, as registration, audio call or other IN service etc.; LEA issues snoop command in the CS territory of VCC user attaching for another example, then can only listen to the miscellaneous service of VCC user in the CS territory.When existing legal listening method can't guarantee that also VCC user's connection switches simultaneously, the continuity of Lawful Interception was switched in calling procedure as VCC user, then can't carry out Lawful Interception to the VCC user after switching, and can not guarantee the continuity of monitoring.

Summary of the invention

Embodiment of the present invention provides a kind of legal interception system, methods and applications server, utilizes VCC application server controls medium gateway function physical replication Media Stream, can realize the business under all application scenarioss of VCC user is all monitored.

A kind of legal interception system that embodiment of the present invention provides comprises: continuous voice call VCC application server and medium gateway function entity;

The VCC application server is arranged in VCC user's traffic signaling route, and the VCC application server is in the service media route according to the listen requirement control medium gateway function entity to the VCC customer service;

After the medium gateway function entity is in the service media route, duplicate VCC user's service media stream, and output.

Embodiment of the present invention also provides a kind of legal listening method, and described method comprises:

The VCC application server that is arranged in VCC user's traffic signaling route is in the service media route according to the listen requirement control medium gateway function entity to the VCC customer service;

Described medium gateway function entity duplicates VCC user's service media stream according to the control of VCC application server, and output.

Embodiment of the present invention also provides a kind of application server, be the VCC application server, be arranged in VCC user's traffic signaling route, be provided with the Lawful Interception control module in the described VCC application server, this Lawful Interception control module is according to the listen requirement of VCC customer service is controlled the medium gateway function entity, described medium gateway function entity is joined in the service media route, and control medium gateway function physical replication and export VCC user's service media stream.

Description by technique scheme as can be known, because the VCC application server in the embodiment of the present invention can be in the service media route according to the listen requirement control medium gateway function entity to VCC user, therefore, no matter be to set up in the business procedure VCC user, still after VCC user carries out the business switching, the medium gateway function entity all can be in the service media route, like this, the medium gateway function entity can duplicate and export VCC user's service media stream all the time, thereby can monitor the service media stream of VCC user in various application scenarioss, guarantee to monitor the integrality of content, guaranteed the continuity of snoop procedure.

Description of drawings

Fig. 1 is the Lawful Interception network model schematic diagram of IMS network;

Fig. 2 is the control schematic diagram of the VCC AS of embodiment of the present invention to VCC MGF;

Fig. 3 is the legal interception system schematic diagram of embodiment of the present invention;

Fig. 4 is the Lawful Interception implementation procedure flow chart one of embodiment of the present invention;

Fig. 5 is the Lawful Interception entity process flow diagram two of embodiment of the present invention.

Embodiment

The legal interception system that embodiment of the present invention provides comprises: VCC application server and medium gateway function entity.The medium gateway function entity can be called VCC MGF entity.VCC MGF entity can be the gateway function entity of an IP to IP.

Carry out in business such as the calling procedure VCC user, VCC AS is in the traffic signaling route.This business can be the business of initiating from the CS territory, also can be the business of initiating from the IMS territory, certainly, can also be that initiate in other territories.VCC AS can be when listening to the VCC user that monitored movable, report interface to report the VCC user's who is monitored IRI Intercept related information by IRI, when initiating register requirement in the IMS territory as VCC user, VCC AS can perceive the registration of VCC user in the IMS territory by modes such as third-party registration or subscribing notifications, and VCC AS monitors and report the IRI Intercept related information that listens to; When VCC user initiated register requirement in the CS territory for another example, VCC AS can perceive the registration of VCC user in the CS territory by modes such as IN service triggerings, and VCC AS monitors and report the IRI Intercept related information that listens to.

When described business was calling, the VCC user in the embodiment of the present invention can be the calling subscriber, also can be the called subscriber.

Embodiment of the present invention does not limit the concrete form of VCC user access network, and promptly VCC user can realize VCC user's registration, VCC customer call, VCC user's miscellaneous service operational processes such as operation layer switching by multiple Access Network.

VCC AS in the embodiment of the present invention is according to VCC user's listen requirement is controlled the VCCMGF entity.To VCC user's listen requirement can for: determining need monitor VCC user's business the time, controlling VCC MGF entity immediately adds in the service media route, also can for: determining and need monitor and controlled condition when satisfying VCC user's business, control VCC MGF entity adds in the service media route.The controlled condition here can be for following one or more: whether the territory at VCC user place meets the requirements, as VCC user whether in the territory that issues snoop command and/or time of adding in the service media route of control VCCMGF entity whether meet the requirements, when whether switching etc. as VCC user.The present invention does not limit the particular content of controlled condition.

The VCC AS that is in the call signaling route determines to have the method that VCC user's business is monitored multiple, receive the monitoring information that listening center such as LI ADMF (Lawful Interception management function entity) issue as VCC AS, and determine that according to the monitoring information that receives needs monitor VCC user's business; VCC AS determines that according to its monitoring information of storing in advance needs monitor VCC user's business for another example, and Cun Chu monitoring information can be a static configuration in advance, also can be that VCC AS downloads from other network equipments; Monitoring information can also obtain from call-signaling message in addition.VCC AS can receive VCC user's monitoring information by existing data-interface, and VCC AS can adopt existing method to receive monitoring information, also can receive monitoring information by self-defining signaling.Embodiment of the present invention does not limit the method that VCC AS obtains VCC user's monitoring information.

Above-mentioned monitoring information should comprise the information that is used for unique identification VCC user, and VCC AS can judge VCC user in the calling according to the VCC user totem information in the monitoring information and the VCC user totem information of participate in calling out, and whether needs are monitored.

Above-mentioned listening center can be for one or more, and promptly VCC AS can receive the monitoring information that one or more listening center transmission come.

VCC AS to the control of VCC MGF as shown in Figure 2.Among Fig. 2, VCC AS is after basis determines that to VCC user's listen requirement needs control VCC MGF entity is in this professional medium route, VCC AS can control VCC MGF entity and add in the professional medium route, and VCC AS also can control in the service media route after the VCC MGF that has added in the service media route keeps switching.VCC AS can export by eavesdropping target's IRI information, as reporting by eavesdropping target's IRI to listening center after definite need the monitoring VCC user's business.

The VCC MGF entity that is in the service media route can be after VCC AS controls in its adding service media route, directly duplicate and export the conversation Media Stream, VCC MGF entity also can duplicate and export the conversation Media Stream after receiving the copy command that other network equipments such as VCC AS issue.VCC MGF entity can adopt the existing output of duplicating that conversation Media Stream method is conversed Media Stream of duplicating, and embodiment of the present invention does not limit the duplicate output procedure of VCC MGF entity to the conversation Media Stream.

Network configuration below in conjunction with the legal interception system of 3 pairs of embodiment of the present invention of accompanying drawing describes.

Among Fig. 3, VCC AS is positioned at the execution call continuity in IMS territory of VCC user attaching and the functional entity of legal monitoring business logic.

VCC MGF provides Lawful Interception RTP (RTP) function that Streaming Media duplicates.The interface of setting between VCC MGF and the VCC AS is the E1 interface, and the interface protocol of E1 interface can be SIP, also can be agreement H.248.VCC MGF can be independent function entity, also can close with VCC AS and establish, and promptly VCC MGF can be arranged at the inside of VCC AS, and at this moment, the interface between VCC MGF and the VCCAS can be self-defining internal interface.

VCC MGF can directly be connected with VCC AS, and promptly VCC AS can directly control VCC MGF; VCC MGF also can be connected indirectly with VCC AS, and promptly VCC AS controls VCC MGF indirectly by other network elements.When VCC MGF is connected indirectly with VCC AS, network element between VCC MGF and the VCCAS can be finished operations such as protocol message forwarding or protocol message conversion, as adopting Session Initiation Protocol between VCC AS and this network element, this network element is converted to this Session Initiation Protocol and H.248 waits agreement control VCCMGF.

When VCC AS controls VCC MGF indirectly by other network elements, can also comprise in the legal interception system that embodiment of the present invention provides: VCC MGCF (MGCF) entity, like this, VCC AS can directly not control VCC MGF, but realizes control to VCC MGF by VCC MGCF.VCC MGCF can be an independent function entity, also can close with other functional entity and establish, and is made as same functional entity as closing with VCC MGF, closes with VCC AS for another example and is made as same functional entity.When VCC MGCF was independent function entity, the interface protocol between VCC MGCF and the VCC MGF can adopt SIP or H.248.Interface protocol between VCC AS and the VCC MGCF can adopt SIP.

In embodiment of the present invention, can trigger VCC AS according to the iFC (initial filter criteria) of VCC AS correspondence, to realize Lawful Interception; As the iFC triggering VCCAS of S-CSCF according to VCC AS correspondence.Realize network element such as LI-AS owing to also may there be other Lawful Interceptions at present, therefore the iFC that triggers the Lawful Interception implementation procedure has a plurality of, as storing a plurality of iFC among the S-CSCF, comprising the iFC of VCCAS correspondence and the iFC of other Lawful Interceptions realization network element correspondence.If a plurality of iFC all are triggered, then can cause the wasting of resources.Because the UE in the embodiment of the present invention is VCC UE, even VCC UE is not monitored, the calling of VCC UE also can be triggered on the VCC AS, therefore, for avoiding the wasting of resources, the priority that embodiment of the present invention can be provided with the iFC of VCC AS correspondence is higher than the priority that other Lawful Interceptions are realized the iFC of network element correspondence, realizes network element thereby avoid triggering other Lawful Interceptions.And, even if triggered the iFC that a plurality of Lawful Interceptions are realized network element simultaneously, also can control other Lawful Interceptions and realize that network element no longer carries out any snoop-operations by modes such as signaling indications, the snoop-operations here is as duplicating output media stream etc.

Legal interception system that embodiment of the present invention provides and method can be monitored VCC user's various service applications scene, and being example with several concrete execution mode of call business below describes the system and method for embodiment of the present invention.

Execution mode one, control VCC MGF adds in the service media route and carries out Lawful Interception when call setup.

VCC AS receives the initial call conversation request, judges VCC user need be monitored and need the output eavesdropping target in its territory, place Content of Communication, and VCC AS control VCC MGF joins in the medium route of this calling.VCC MGF duplicates and exports the conversation Media Stream after adding calling medium route.

In execution mode one, VCC AS can judge VCC user's needs according to the snoop command that listening center issues in territory, VCC user place and be monitored in its territory, place; VCC AS also can judge VCC user's needs according to the snoop command that listening center other territories outside territory, VCC user place issue and be monitored in the territory, place; VCC AS can also judge VCC user's needs according to the snoop command that listening center all issues and be monitored in its territory, place in territory, VCC user place and other territories.

Execution mode two, control VCC MGF adds to call out in the medium route and carries out Lawful Interception when call setup, switches the back and keeps VCC MGF still to be in calling out in the medium route calling out, and proceed Lawful Interception.In this embodiment VCC user to switch the territory at preceding place be the territory, source, the territory of switching the place, back is the purpose territory.

VCC AS receives the initial call conversation request, and judging VCC user need be the Content of Communication that the output eavesdropping target was monitored and needed in territory, current place in the territory, source, and VCC AS control VCC MGF joins in the medium route of this calling.VCC MGF duplicates and exports the conversation Media Stream after adding calling medium route.

VCC AS is when receiving VCC user's handoff request, and VCC AS keeps VCC MGF to keep calling out in the medium route, and after switching, VCC AS control VCC MGF keeps in the calling medium route after the switching, and VCC MGF continues to duplicate the conversation Media Stream.

In execution mode two, VCC AS can according to the snoop command that listening center issues in VCC user source territory judge VCC user's needs in the territory, source and the purpose territory monitored; VCC AS also can according to the snoop command that listening center issues in VCC customer objective territory judge VCC user's needs in the territory, source and the purpose territory monitored; VCC AS can also according to listening center in VCC user source territory and the snoop command that all issues of purpose territory judge VCC user's needs in the territory, source and the purpose territory monitored.

Execution mode three, when call setup, VCC MGF add do not called out in the medium route, in calling out the calling medium route that will VCC MGF adds after switching after switching, carry out Lawful Interception.

After VCC AS receives the initial call conversation request, judge VCC user had been monitored and needed the output eavesdropping target in its territory, place Content of Communication, VCC AS can utilize the method for existing output communication content to monitor, and VCC AS does not carry out control and treatment to VCC MGF.After VCC AS received the VCC handoff request, VCC AS control VCC MGF joined in the calling medium route after the switching.VCC MGF duplicates and exports the conversation Media Stream after the calling medium route that adds after switching.

In execution mode three, VCC AS can judge VCC user's needs according to the snoop command that listening center issues and be monitored in the territory, source in VCC user source territory; VCC AS also can judge VCC user's needs according to the snoop command that listening center issues in VCC customer objective territory and be monitored in the territory, source; VCC AS can also according to listening center in VCC user source territory and the snoop command that all issues of purpose territory judge VCC user's needs and monitored in the territory, source.

In above-mentioned three kinds of execution modes, the specific implementation process that VCCAS control VCC MGF joins in the medium route can be: VCC AS by H.248 or Session Initiation Protocol control VCC MGF set up context, topological structure in the context can be (T1, T2, bothway), (T1, T3, oneway), (T2, T4, oneway); Be that VCC AS order VCC MGF duplicates the Media Stream that is sent by the eavesdropping target and orders VCC MGF to duplicate the Media Stream that is received by the eavesdropping target.Contextual topological structure also can for (T1, T2, bothway), (T1, T3, oneway), (T1, T4, Onewayexternal); Be that VCC AS order VCC MGF duplicates the Media Stream that is sent by the eavesdropping target and orders VCC MGF to duplicate the Media Stream that is received by the eavesdropping target; Contextual topological structure can also for (T1, T2, bothway), (T1, T3, onewayboth); Be that VCC AS order VCC MGF duplicates the Media Stream that is sent and receive by the eavesdropping target, but can't distinguish this moment Media Stream by the eavesdropping target send, still be by the eavesdropping target receive etc.Above-mentioned contextual topological mode all can be finished duplicating by eavesdropping target's Media Stream.

In above-mentioned execution mode two and execution mode three, VCC AS control VCC MGF keep switch the medium route of calling out the back method can for: VCC AS makes amendment to the context among the VCCMGF according to concrete VCC handoff procedure, VCC MGF is kept in the medium route, and duplicate media stream.VCCAS to the contextual modification among the VCC MGF as endpoint characteristics in the context is carried out corresponding modify etc.Embodiment of the present invention does not limit the specific implementation that VCC AS control VCC MGF is in the medium route of calling.

Below to describing by the process of duplicating of transmitting topology information realization conversation Media Stream.

VCC AS carries the topology of monitoring media stream duplication and describes in the message that transfers to VCC MGF, described by the topology that VCC MGF monitors media stream duplication according to the message parse of its reception, and describe duplicate media stream according to this topology.

When VCC AS describes in the topology that adopts SIP to transmit the monitoring media stream duplication, then can relate to the protocol extension of SIP, concrete expansion can for: by expanding a application type based on the XML form, realize the protocol extension of SIP, then, carrying the topology of monitoring media stream duplication by message body describes.XML message body can be following form:

Content-type:application/session-topology+xml

<？xml?version＝″1.0″？>

<session-topology?xmlns＝″urn:ietf:params:xml:ns:session-topology″

version＝″0″state＝″full″

entity＝″sip:alice@example.com″>

<session?name＝″abcd@example.com″>

</copiedstream>

<direction>upstream</direction>

</session>

</interception-data>

XML message body in the above-mentioned example provides current calling and need copy from [5555::1:2:3:4]: 1357 to [5555::a:b:c:d]: 7531 RTP up (upstream) Media Stream.

What deserves to be explained is, above-mentioned about carrying the transmittance process that topology that expansion that the topology of monitoring media stream duplication describes can adopt this extended method to realize monitoring media stream duplication just to the explanation embodiment of the present invention is described, and understood by VCC MGF and carry out, thereby make VCC MGF can carry out duplicating of Lawful Interception media data flow, this does not also mean that SIP must expand according to the above-mentioned mode that provides, other extended mode, describe as long as can transmit the topology of monitoring media stream duplication, and can just can by VCCMGF identification.Embodiment of the present invention does not limit the concrete manifestation form of SIP expansion.

Legal interception system and legal listening method below in conjunction with 4 pairs of embodiment of the present invention of accompanying drawing describe.In this embodiment, VCC AS adopts the method for revising the mutual media information of session both sides, and VCC MGF is inserted in the medium route; And, exist on the VCC MGF with the direct-connected interface of VCC AS and interface protocol to be agreement H.248.VCC AS that is to say that as MGC (MGCF) VCC AS possesses MGCF, can control VCC MGF.VCCAS adopts existing H.248 agreement directly to control VCC MGF.The calling party who sets basic call is by the eavesdropping target.

Among Fig. 4, the VCC user who is monitored to step 2, quilt in step 1 makes a call as the calling party who calls out.During this call request process S-CSCF, trigger the VCC initial filter criteria among the S-CSCF, S-CSCF is routed to VCC AS with call request.

Receive according to it that call request determines that the calling party who calls out is monitored and during needs output communication content in step 3 to step 10, VCC AS, VCC AS uses H.248 agreement control VCC MGF, on VCC MGF, create a context, in the context of described establishment, create end points T1 and T3, and the topological structure that is provided with between T1 and the T3 is oneway, and promptly T3 is only to receive the one-way media stream of T1.Then, setting up T3 is connected with carrying to the calling of DF3, in described context, create end points T2 again, the topological structure that is provided with between T2 and the T1 is bothway, the session connection attribute of VCC AS request for utilization is replaced IP address and the RTP port number information that calling party SDP (Session Description Protocol) describes in the call request message, calls out in the route oneself joining.VCC AS returns the call request route to S-CSCF.

Step 11 is receiving the call request that route returns to step 13, S-CSCF after, the identify label of the DNS among the S-CSCF (domain name system) resolving called, and this call request sent to next-hop node.This call request finally arrives the callee.After the callee responded this call request, loopback 200OK message carried the medium type that callee SDP describes and selects in the 200OK message.This message is routed to VCC AS through behind the S-CSCF.

Creates end points T4 in step 14 to step 16, VCC AS indication VCC MGF in described context, and the topological structure that is provided with between T2 and the T4 is oneway, promptly T4 is only to receive the one-way media stream of T2, then, sets up T4 and is connected with carrying to the calling of DF3.

The callee SDP that revises among the called party answer message 200OK in step 17 to step 18, VCC AS describes, the callee SDP that promptly uses the session connection attribute of applying on the VCC MGF to substitute among the 200OK describes, and called party answer message 200OK sent to next jumping, this called party answer message 200OK finally arrives the calling party.

In the execution mode of above-mentioned Fig. 4, VCC AS can make corresponding modification to the endpoint characteristics in the context of having set up as required when receiving Temporary Response or 200OK etc.VCC AS joins VCC MGF in the calling medium route in call establishment.In fact, VCC AS also can make the tandem of both call sides Media Stream to VCC MGF by the media redirection flow process after conversation is set up, and to reach the purpose of inserting VCC MGF in the conversation Media Stream, just VCC MGF is added in the medium route.As receive callee's call answering message 200OK as VCC AS after, indication VCC MGF creates context and adds corresponding endpoint, VCC AS is after the resource bid success, use the session connection attribute to replace the media description of calling both sides, then, be initiated to the media redirection flow process of calling both sides respectively, the media redirection that makes calling both sides is to VCC MGF, thereby makes the tandem of both call sides Media Stream to VCC MGF.VCC AS sends the topological logic information that is used for media stream duplication that carries to VCC MGF, and VCC MGF is according to described topological logic information reproduction conversation Media Stream.

Legal interception system and legal listening method below in conjunction with 5 pairs of embodiment of the present invention of accompanying drawing describe.In this embodiment, VCC user need switch to the CS territory from the IMS territory.

Among Fig. 5, step 1 to step 2, by the VCC user that monitored with VCC AS as the called handoff request that makes a call, this call handover request is routed to VCC AS.

After step 3 and step 4, VCC AS detect the grappling session according to the user ID in the call handover request, act on behalf of VCC user and the callee holds consultation again.

Extract the callee SDP that message is carried in the negotiations process in step 5 to step 12, VCC AS and describe, VCC AS is when context end points T1, T2, T3 and T4 make amendment in determining not need VCC MGF, to step 13.VCC AS determine need be to VCC MGF in context end points T1, T2, T3 and T4 when making amendment, then revise the characterisitic parameter of context end points T1, T2, T3 and T4 among the VCC MGF, make VCC MGF connect the both call sides Media Stream.In above-mentioned end points modification process,, then need between VCC AS and DF3, rebulid and call out and bearer path if variation has taken place the medium property of end points T3, T4.

In fact, step 5,7,9 among Fig. 5,11 modify order can merge, and merge into a modify order as two or more arbitrarily.

The callee SDP that revises among the called party answer message 200OK in step 13 to step 14, VCC AS describes, the callee SDP that promptly uses the session connection attribute of applying on the VCC MGF to substitute among the 200OK describes, and called party answer message 200OK sent to next jumping, this called party answer message 200OK finally arrives the calling party.

What deserves to be explained is, in the flow process of above-mentioned Fig. 4, Fig. 5, VCC AS sets up the media description of mutual both sides in the signalling route by control VCC MGF and by revising session, makes the tandem of both call sides Media Stream in VCC MGF, thereby is implemented in the purpose of inserting VCC MGF in the medium route.This process does not influence the media negotiation of both call sides, and concrete reason is: in the both call sides interactive signaling, VCC AS only revises both sides IP address and the RTP port numbers in the media description, does not change the encoding scheme that both sides consult.Like this, VCC MGF has realized providing Lawful Interception media stream duplication function as a gateway function entity that is positioned at the IP to IP in controlled user attaching territory.

In the execution mode that above-mentioned Fig. 4, Fig. 5 describe, omit some interim message in the calling procedure, as omitted 100 response messages etc. of Invite message.

In the execution mode of above-mentioned Fig. 4, Fig. 5, H.248 VCC AS is to use agreement directly to control VCCMGF.VCC AS also can use the XML body of expansion to carry the Media Stream topological logic in sip message, and VCC MGF duplicates conversation Media Stream and output after parsing this topological logic.That is to say, the implementation procedure of Lawful Interception can for: when call request arrived VCC AS, VCC AS control VCC MGF created context, adds end points, and the SDP in the replacement call request describes, then, with oneself joining in the call signaling route, call request is sent to next jumping.When VCC AS receives called party answer message, VCC AS sends the XML body that carries expansion to VCC MGF and monitors the Media Stream topological logic, VCCMGF parses the monitoring Media Stream topological logic in this XML body, and duplicates corresponding conversation Media Stream and output according to this topological logic.

Provided when VCC user is monitored as the calling party under the non-resource reservation situation in the execution mode that above-mentioned Fig. 4, Fig. 5 describe, VCC MGF duplicates the implementation procedure of conversation Media Stream.In fact, under the resource reservation situation, VCC AS can describe by the SDP in control VCC MGF, the modification both call sides Signalling exchange equally and reach the purpose of inserting VCC MGF in the medium route.Still be example as the calling party by monitoring with VCC user below, the Lawful Interception implementation procedure under the resource reservation situation is described.

At first, the VCC user who is monitored makes a call as the calling party who calls out.During this call request process S-CSCF, trigger the VCC initial filter criteria among the S-CSCF, S-CSCF is routed to VCC AS with call request.VCC AS joins oneself in the signalling route.

VCC AS applies for resource on VCC MGF after judging the quilt monitoring of caller VCC user needs and being needed the output communication content.VCC AS is when receiving the signaling message that carries the SDP description of calling out the either party, and the SDP that VCC AS uses the resource of applying on VCC MGF to replace calling both sides describes, and makes the tandem of both call sides Media Stream to VCC MGF.

Then, VCC MGF duplicate media stream and output.

In the description of above-mentioned execution mode, monitored as the calling party with VCC user and VCC user switch to the CS territory from the IMS territory be that example describes.When VCC user monitored as the calling party and this VCC user when the CS territory switches to the IMS territory, VCC AS equally can be by being modified in the session connection attribute on the VCC MGF, VCC MGF is in the medium route, thereby reaches the purpose of duplicating the conversation Media Stream.When VCC user is monitored as the callee, the S-CSCF of this VCC user's registration can adopt in the same way at the VCC AS that routes the call to VCC user attaching territory, and be in the medium route, thereby reach the purpose of duplicating the conversation Media Stream by this VCC AS control VCC MGF.VCC user switch to the Lawful Interception implementation procedure in IMS territory from the CS territory and VCC user switches to the CS territory from the IMS territory Lawful Interception implementation procedure basic identical.At this above-mentioned various execution mode is not described in detail.

Be that example describes in the above-described embodiment with the basic call, the technical scheme that embodiment of the present invention provides goes for application scenarioss such as other VCC business equally.

Below the application server in the embodiment of the present invention is described.

Application server in the embodiment of the present invention is VCC AS, realizes in the business procedure VCC user, and VCC AS is arranged in VCC user's traffic signaling route.Be provided with the Lawful Interception control module among this VCC AS, main being operating as of this Lawful Interception control module: the medium gateway function entity is controlled according to listen requirement to the VCC customer service, described medium gateway function entity is joined in the service media route, and control medium gateway function physical replication and export VCC user's service media stream.Lawful Interception control module among the VCC AS can be controlled VCC MGF entity and add in the professional medium route, and the Lawful Interception control module also can be controlled in the service media route after the VCC MGF that has added in the service media route keeps switching.The Lawful Interception control module can also be exported by eavesdropping target's IRI information, as reporting by eavesdropping target's IRI to listening center.The Lawful Interception control module can issue copy command to VCC MGF entity, with the time of control VCC MGF physical replication and output conversation Media Stream.The Lawful Interception control module can by H.248 or Session Initiation Protocol control VCC MGF set up context, VCCMGF is in the service media route with control.Concrete as the description in the execution mode of above-mentioned method and system, no longer describe in detail at this.

As can be seen, embodiment of the present invention can be monitored the activity of VCC user in any territory from the description of above-mentioned execution mode, even if handover operation has taken place, also can guarantee the continuity of Lawful Interception.

Though described the present invention by embodiment, those of ordinary skills know, the present invention has many distortion and variation and do not break away from spirit of the present invention, and the claim of application documents of the present invention comprises these distortion and variation.

Claims

1, a kind of legal interception system is characterized in that, described system comprises: continuous voice call VCC application server and medium gateway function entity;

After the medium gateway function entity is in the service media route, duplicate VCC user's service media stream, and output;

Described VCC application server is in the service media route according to the listen requirement control medium gateway function entity to the VCC customer service and comprises:

Described VCC application server is set up in the process in business, to described medium gateway function entity application session connection resource, and, described medium gateway function entity is joined in the service media route according to the information that the Session Description Protocol in the described session connection resource modifying signaling message is described; Perhaps

Described VCC application server is controlled described medium gateway function entity application session connection resource behind call setup, and according to described session connection resource initiation media redirection flow process described medium gateway function entity is joined in the service media route.

2, the system as claimed in claim 1 is characterized in that:

Described VCC application server is set up in the process or in business in VCC user's business and is successfully set up afterwards or in service switch process, control the medium gateway function entity and add in the service media route; Perhaps

Described VCC application server is in VCC user's service switch process, and the medium gateway function entity that control has been in the service media route continues to be in the service media route.

3, the system as claimed in claim 1 is characterized in that: the doubling time of described VCC application server controls medium gateway function entity, media gateway duplicate VCC user's service media stream according to the doubling time of VCC application server controls.

4, the system as claimed in claim 1 is characterized in that, described medium gateway function entity is: the gateway of IPto IP.

5, the system as claimed in claim 1 is characterized in that, described medium gateway function entity is an independent function entity, or described medium gateway function entity is arranged in the VCC application server.

6, the system as claimed in claim 1 is characterized in that: described VCC application server transfers to described medium gateway function entity with topological descriptor and/or VCC user's monitored data; Described medium gateway function entity is according to the topological descriptor and/or the VCC user's monitored data duplication service Media Stream that receive, and output;

Described topological descriptor is for monitoring the topological descriptor of media stream duplication.

7, system as claimed in claim 6, it is characterized in that described VCC application server is carried on described topological descriptor and/or VCC user's monitored data among the Session initiation Protocol SIP of the H.248 agreement of expansion and/or expansion and transfers to described medium gateway function entity.

8, a kind of legal listening method is characterized in that, described method comprises:

Described medium gateway function entity duplicates VCC user's service media stream according to the control of VCC application server, and output;

9, method as claimed in claim 8 is characterized in that, the step that described VCC application server controls medium gateway function entity is in the service media route comprises:

10, method as claimed in claim 8 is characterized in that, the step that described medium gateway function entity duplicates VCC user's service media stream according to the control of VCC application server comprises:

Described VCC application server transfers to described medium gateway function entity with topological descriptor and/or VCC user's monitored data; Described medium gateway function entity is according to the topological descriptor and/or the VCC user's monitored data duplication service Media Stream that receive;

11, a kind of application server, be the VCC application server, be arranged in VCC user's traffic signaling route, it is characterized in that, be provided with the Lawful Interception control module in the described VCC application server, this Lawful Interception control module joins described medium gateway function entity in the service media route according to the listen requirement of VCC customer service is controlled the medium gateway function entity, and control medium gateway function physical replication and export VCC user's service media stream;

Set up in the process in business, described Lawful Interception control module is to described medium gateway function entity application session connection resource, and, described medium gateway function entity is joined in the service media route according to the information that the Session Description Protocol in the described session connection resource modifying signaling message is described; Perhaps

Behind call setup, described Lawful Interception control module is controlled described medium gateway function entity application session connection resource, and according to described session connection resource initiation media redirection flow process described medium gateway function entity is joined in the service media route.

12, application server as claimed in claim 11 is characterized in that:

Described Lawful Interception control module is set up in the process or in business in VCC user's business and is successfully set up afterwards or in service switch process, control the medium gateway function entity and add in the service media route; Perhaps described Lawful Interception control module is in VCC user's service switch process, and the medium gateway function entity that control has been in the service media route continues to be in the service media route.