JP2022157371A - Communication interception system, communication interception device, communication interception method, and program - Google Patents

Abstract

To provide a technology capable of intercepting all communication to be intercepted from the start of communication.SOLUTION: A communication interception system includes: a communication control device that acquires information capable of specifying an identifier of an interception target user, receives a session start request requesting establishment of a session, forwards the session start request to a communication interception device when the received session start request includes the acquired identifier and it is determined that the session start request satisfies a predetermined condition, and forwards the session start request to a network node different from the communication interception device when it is determined that the session start request does not meet the predetermined conditions; and the communication interception device that establishes a session such that communication is performed via the communication interception device when the session start request is received, and intercepts the communication in the established session.SELECTED DRAWING: Figure 4

Description

The present invention relates to a communication interception system, a communication interception device, a communication interception method, and a program.

There has been proposed a technique for intercepting communication between communication terminals connected via a communication network (Patent Document 1).

JP 2008-270899 A

Here, with the technology described in Patent Document 1, after a session is established, the session is already established and then intercepted, so there are cases where part of the communication to be intercepted cannot be intercepted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a technique that enables interception of all communications to be intercepted from the start of the communication.

In order to achieve the above object, a communication interception system according to one aspect of the present invention includes:
A communication interception system comprising a communication interception device and a communication control device,
The communication control device is
Acquisition means for acquiring information capable of identifying an identifier of an interception target user;
receiving means for receiving a session initiation request requesting establishment of a session;
When the received session initiation request includes the identifier obtained by the obtaining means,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer means;
with
The communication interception device is
session establishment means for establishing a session so that communication is performed via the communication interception device when the session start request is received;
interception means for intercepting communication in the session established by the session establishment means;
characterized by comprising

Further, in order to achieve the above object, a communication interception device according to an aspect of the present invention includes:
A communication interception device,
Updating session description protocol information included in the session initiation request so that communication is performed via the communication interception device when the session initiation request is received from another network node, and the updated session initiation request. to the other network node; and
an interception means for intercepting communications in a session via the communication interception device;
characterized by comprising

Further, in order to achieve the above object, a communication interception method according to an aspect of the present invention includes:
A communication interception method for a communication interception system comprising a communication interception device and a communication control device,
an acquisition step in which the communication control device acquires information capable of specifying an identifier of an interception target user;
a receiving step for receiving a session initiation request requesting establishment of a session;
When the session initiation request received by the communication control device includes the identifier obtained in the obtaining step,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer step;
a session establishment step of establishing a session so that communication is performed via the communication interception device when the communication interception device receives the session initiation request;
an interception step in which the communication interception device intercepts communications in the session established in the session establishment step;
characterized by comprising

Further, in order to achieve the above object, a communication interception method according to an aspect of the present invention includes:
A communication interception method for a communication interception device,
Updating session description protocol information included in the session initiation request so that communication is performed via the communication interception device when the session initiation request is received from another network node, and the updated session initiation request. to the other network node; and
an interception step of intercepting communications in a session via the communication interception device;
characterized by comprising

Further, in order to achieve the above object, a program according to one aspect of the present invention includes:
In the computer of the communication interception device,
Updating session description protocol information included in the session initiation request so that communication is performed via the communication interception device when the session initiation request is received from another network node, and the updated session initiation request. to the other network node; and
an interception step of intercepting communications in a session via the communications interception device;
is characterized by executing

Further, in order to achieve the above object, a program according to one aspect of the present invention includes:
A communication interception system comprising a communication interception device and a communication control device,
an acquisition step in which the communication control device acquires information capable of specifying an identifier of an interception target user;
a receiving step for receiving a session initiation request requesting establishment of a session;
When the session initiation request received by the communication control device includes the identifier obtained in the obtaining step,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer step;
a session establishment step of establishing a session so that communication is performed via the communication interception device when the communication interception device receives the session initiation request;
an interception step in which the communication interception device intercepts communications in the session established in the session establishment step;
is characterized by executing

Advantageous Effects of Invention According to the present invention, it is possible to provide a technology that enables interception of communication to be intercepted from the start of the communication without omission.

The figure which shows an example of the communication system to which the communication interception system which concerns on this embodiment is applied. FIG. 2 is a diagram showing configurations of an interception server, CSCF, and HSS according to the embodiment; FIG. 4 is a diagram showing an example of a call processing path for establishing a session that does not include an interception target user; FIG. 10 is a diagram showing an example of a call processing path for establishing a session when an interception target user makes a call; FIG. 4 is a control sequence diagram for establishing a session when an interception target user makes a call; FIG. 4 is a control sequence diagram for establishing a session when an interception target user receives a call; 4 is a flowchart showing an example of processing executed by a communication interception system; The figure which shows an example of forwarding destination information. Schematic diagram showing an example of the structure of a control signal. FIG. 4 is a control sequence diagram when communication is disconnected in the communication interception system; FIG. 10 is a control sequence diagram when the communication interception system is put on hold/released from the hold; FIG. 11 is a diagram showing a method of setting information of an interception target user; (A) is a diagram showing the session start request before being updated by the interception server, and (B) is a diagram showing the session start request after being updated by the interception server.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In addition, the following embodiments do not limit the invention according to the scope of claims. Although multiple features are described in the embodiments, not all of these multiple features are essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant description is omitted.

<System configuration>
FIG. 1 shows a communication system to which a communication interception system according to this embodiment is applied. An interception system 10 is applied to the communication system 1 of FIG. A communication system 1 includes an access/packet device 2 on an originating side (hereinafter also referred to as an originating UE2 or UE2) and a terminal device 3 on a terminating side (hereinafter also referred to as a terminating UE3 or UE3). networks 5a and 5b (hereinafter sometimes referred to without distinction as access/packet network 5). The communication system 1 also includes gateway devices (GW) 6a and 6b (hereinafter referred to as GW 6), media gateway devices (MGW) 7a and 7b (hereinafter sometimes referred to as MGW 7 without distinction), and Telephony Application Servers (TAS) 8a and 8b (hereinafter collectively referred to as TAS 8) (which may be the case).

The interception system 10 also includes an interception server 11, a Home Subscriber Server (HSS) 12, and call session control functions (CSCF) 13a and 13b (hereinafter sometimes referred to as CSCF 13 without distinction). The interception system 10 is also connected to a maintenance network (NW) 14 and connected to a maintenance device 15 . Also, the interception server 11 is configured to be able to communicate with the interception client 4 via the interception client NW20.

Note that the IMS NW may include other network nodes in addition to the nodes shown in FIG. Also, each node in the IMS NW may be able to communicate with each other through paths other than those indicated by solid lines. For example, CSCFs 13a and 13b can transmit and receive control signals, and MGWs 7a and 7b can transmit and receive voice signals. Also, each of the network nodes shown in FIG. 1 may be merged or split.

In FIG. 1, for the sake of simplicity, the access/packet networks 5a and 5b to which the originating UE 2 and the terminating UE 3 are connected are illustrated as being connected to the same IMS NW. It may connect to different IMS NWs. In such a case, there may be a network node (not shown) such as an exchange that connects multiple IMS NWs. Also, the network nodes in the IMS NW are connected by solid lines to clarify the communication paths, but any other network nodes such as switches and routers may exist between each network node.

UEs 2 and 3 are terminal devices connectable to a base station (not shown) of the access/packet network 5, and mobile terminals such as smartphones, for example.

Access/packet network 5 is an access network that allows UEs 2 and 3 to connect to a communication system, such as Long Term Evolution (LTE) networks, LTE-Advanced (LTE-A) networks, and Evolved Packet Cores. (EPC) network and/or

GW 6 is a gateway device that enables connection from access/packet network 5 to IP Multimedia Service (IMS) networks including MGW 7 , TAS 8 and CSCF 13 .

The MGW 7 has an interface function for audio data exchanged in a session between the UEs 2 and 3, and performs audio codec on the audio data using Realtime Transport Protocol (RTP). The TAS 8 performs call-additional services such as call forwarding.

Here, configurations of interception server 11, HSS 12 and CSCF 13 will be described with reference to FIG.

The interception server 11 is a communication interception device that includes a control unit 111 , a storage unit 112 and a communication unit 113 . The control unit 111 is a computer including a processor and a memory, and by executing a program stored in the storage unit 112, a control signal processing unit 111a, an audio signal processing unit 111b, a notification unit 111c, and an intercepted audio providing unit. 111d.

The control signal processing unit 111a performs SIP processing so that voice signals are exchanged via the interception server 11 when the interception target terminal receives a control signal (SIP signal) including a session start request that is an outgoing call or an incoming call. Update signal. This allows the interception server 11 to establish a session via the interception server 11 .

The audio signal processing unit 111b relays the audio signal in the session to be intercepted via the interception server 11, and intercepts the audio signal by extracting the audio signal from the session to be intercepted. Also, the voice signal processing unit 111b stores the call state of the session including the interception target user in the storage unit 112. FIG. The state of a call in a session is, for example, a state such as busy or on hold.

When interception by the interception server 11 is started, the notification unit 111c notifies the interception client 4 of information about the interception target session. The intercepted audio providing unit 111d provides the interception client with the audio signal intercepted by the audio signal processing unit 111b. In one example, the intercepted audio providing unit 111d converts the audio signal into a file format specified by the interception client and provides it. The notification unit 111c may also notify the interception client 4 when the session to be intercepted is held/released/disconnected.

HSS 12 includes control unit 121 , storage unit 122 and communication unit 123 . The control unit 121 is a computer having a processor and a memory, and delivers the interception target user's subscriber contract information (iFC) stored in the storage unit 122 to the CSCF 13 .

The transfer destination information acquisition unit 121 a receives the interception target user's subscriber contract information (iFC) including transfer information to the interception server 11 from the maintenance device 15 and stores the information in the storage unit 122 .

The CSCF 13 is a communication control device that includes a control unit 131, a storage unit 132, and a communication unit 133, and transfers session control signals. The control unit 131 is a computer including a processor and memory. The transfer destination information acquisition unit 131b receives the interception target user's subscriber contract information (iFC) including the transfer information from the HSS 12 to the interception server 11, and based on the contents, the routing unit 131a receives the session start request received by the CSCF. control information to the target network node.

<Session route>
A session established between non-intercepted users will now be described with reference to FIG.

In FIG. 3, a dashed line 301 indicates the flow of control signals (hereinafter also referred to as SIP signals) communicated using the Session Initiation Protocol (SIP). A dashed-dotted line 302 is the flow of audio signals (hereinafter also referred to as RTP signals) communicated using the Realtime Transport Protocol (RTP).

In FIG. 3, the session start request transmitted from the originating UE 2 is transferred in the order of the access/packet network 5a, GW 6a, CSCF 13a, and TAS 8a, and is returned from TAS 8a to CSCF 13a, CSCF 13b, TAS 8b, CSCF 13b, GW 6b, access/packet It is transmitted to the destination UE 3 via the network 5b in that order.

The receiving side UE3 transmits a session start response, which is a response to the session start request, to the calling side UE2 according to the dashed line 301 . Thereafter, after transmission and reception of subsequent control signals such as resource reservation and paging through the same route, a voice signal session is established as indicated by a dashed line 302 . In the voice signal session, the voice signal transmitted from the originating side UE 2 passes through the access/packet network 5a, GW 6a and MGW 7a, and then is transmitted to the receiving side UE 3 via the MGW 7b, GW 6b and access/packet network 5b. .

On the other hand, with reference to FIG. 4, session establishment including an interception target user will be described. In the example of FIG. 4, description will be given assuming that the originating side UE 2 is the terminal of the interception target user. In FIG. 4, dashed line 401 indicates the flow of SIP signals, and dashed line 402 indicates the flow of RTP signals. In the example of FIG. 4, the originating side UE2 is a user to be intercepted (for example, the identifier is xxxx-xxxx-xxxx in FIG. 8), and the terminating side UE3 is not a user to be intercepted (for example, the identifier is zzz-zzzz-zzzz in FIG. ).

In FIG. 4, when the session initiation request transmitted from the originating side UE2 is transmitted to the access/packet network 5a, the GW 6a, and the CSCF 13a, the CSCF 13a receives the iFC containing the subscriber information of the UE2, that is, the transfer destination information for the interception target. forwards the session initiation request to the interception server 11 based on . Interception server 11 updates the received session initiation request so that interception server 11 is included in the audio signal path, and transfers the session initiation request to CSCF 13a. Thereafter, the session start request is transferred in the order of CSCF 13a, TAS 8a, CSCF 13a, CSCF 13b, TAS 8b, CSCF 13b, GW 6b, and access/packet network 5b, and is sent to UE 3 on the receiving side. Since interception server 11 updates the session start request so that a session is established via interception server 11 , RTP signals are transmitted and received as indicated by dashed-dotted line 402 . Therefore, the interception server can intercept the RTP signal.

Note that even when the terminating-side UE 3 is the terminal of the interception target user, the terminating-side CSCF 13b first transfers the session start request to the TAS 8b, transfers the session start request received from the TAS 8b to the interception server 11, and intercepts. By transferring the session start request updated by the server 11 to the GW 6b, the session can be established via the interception server 11 as well.

Similarly, CSCF 13 transfers subsequent control signals (SIP signals) including subsequent session start request responses, provisional responses, final responses, disconnection requests, hold requests, and hold release requests to interception server 11, 11 updates the SIP signal and transfers it to the CSCF 13 to establish a session between the UEs 2 and 3 via the interception server 11, so that the interception server 11 intercepts voice signals (RTP signals) sent and received on the session. be able to.

Here, an example of the structure of the control signal will be described with reference to FIG. Control signals exchanged to manage the session include message type 901 , calling address 902 , called address 903 , session ID 904 , media connection information 905 and media detail information 906 .

A message type 901 indicates the type of signal such as a session start request or session start request response, and in the example of FIG. 9, "INVITE" is set to indicate that the control signal is a session start request. The calling address 902 is an identifier that can identify the user of the calling side UE2, and the called address 903 is an identifier that can identify the user of the called side UE3.

Session ID 904 is the identifier of the session to be established. As a result, it is possible to specify for which session a control signal such as a session initiation request or a response to a session initiation request is intended. Media connection information 905 is data used when establishing a media session, and includes information specifying a network node for establishing a media connection. Media detail information 906 includes information specifying the type of RTP signal exchanged and the network port.

For example, interception server 11 can be configured such that a connection is established through interception server 11 by updating media connection information 905 such that media connection information 905 includes the address of interception server 11 . . Information changed by the interception server 11 will be described later with reference to FIG.

<At the start of the session>
Next, with reference to FIG. 5, the flow of control signals when the originating UE 2 is the terminal of the interception target user will be described. In the example of FIG. 4, the originating side UE2 is a user to be intercepted (for example, the identifier is xxxx-xxxx-xxxx in FIG. 8), and the terminating side UE3 is not a user to be intercepted (for example, the identifier is zzz-zzzz-zzzz in FIG. ).

First, when UE2 starts call origination processing with UE3 as the destination according to user input (processing step 501, hereinafter referred to as 501), UE2 transmits a session start request to CSCF 13a (502). A session initiation request is also called an INVITE message. The CSCF 13a transfers the received session initiation request to the SIP signal according to the transfer destination information obtained from the HSS 12 (503). In one example, the CSCF 13a may store session start requests received within a predetermined period and use them for comparing the identity of the session start requests, which will be described later.

Here, an example of the forwarding destination information of the interception target user will be described with reference to FIG. 8(A). The transfer destination information used by the CSCF 13 is associated with user identifiers, direction of arrival and departure, table reference order, and destinations.

The user identifier is information that can identify at least one of the UE, the owner of the UE, and the subscriber information on the communication system 1, such as the UE address (e.g., IP address, MAC address), telephone number, etc. . The originating/terminating direction indicates whether the UE is originating or terminating. The table reference order corresponds to the number of receptions when the same session initiation request is received. The destination is address information of the transfer destination of the received session initiation request. In one example, the destination is a network address, such as an IP address.

In the example of FIG. 8A, when there is a call from the UE2 with the identifier "xxx-xxxx-xxxx", the CSCF 13a first transfers a control signal such as a session start request to the destination "interception server" with reference order "1". do. This allows the interception server 11 to update the control signal.

On the other hand, in the transfer destination information of the non-interception target user shown in FIG. 8B, there is no referencing order, and the control signal is transferred to the TAS. That is, control signals for sessions between non-intercepted users are not forwarded to the interception server 11 .

At 504 in FIG. 5, a session initiation request is sent to the interception server 11 . Upon receiving the session start request, the interception server 11 updates the received session start request (505) and starts interception processing (506). The interception server 11 updates the session start request so that the calling address, the called address, and the session ID among the parameters of the received session start request are not changed. As a result, in the routing of the CSCF 13a, which will be described later, the interception server 11 uses at least one parameter of the calling address, the called address, and the session ID to perform the session start request before the update and the session start request after the update. are the same session start request.

Here, an example of a session start request received by the interception server 11 and an example of a session start request updated and transmitted by the interception server 11 will be described with reference to FIGS. 13A and 13B.

FIG. 13A shows a session start request received by the interception server 11. FIG. The SIP signal includes control signal route information 1301 , calling address 1302 , called address 1303 , session ID 1304 , media connection information 1305 , and media detail information 1306 . The route information for voice relay is an example of session description protocol information configured according to the Session Description Protocol (SDP).

FIG. 13B is an example of a session start request updated and transmitted by the interception server 11 . As shown underlined, "Record-Route: <sip:bouju@[eeee:ffff:gggg:hhhh::YYYY]; lr>" is added to the route information 1311 of the control signal, and the media connection information 1315 is changed to " c=IN IP6 iii:jjjj:kkkk:llll::ZZZZ" and the media detail information 1316 is changed to "m=audio 12345 RTP/AVP 98 99 100 101 102 103". Thereby, a connection can be established so that the control signal and the voice signal are transmitted and received via the interception server 11 .

Along with the start of interception processing, interception server 11 sends an interception start notification including at least one of the identifier of the calling side (eg, calling address 1302) and the identifier of the called side (eg, called address 1303) included in the session start request. It is sent to the interception client 4 (507), and the session initiation request updated in 505 is returned to the CSCF 13a (508). The CSCF 13a routes the session start request received at 508 according to the transfer destination information.

Referring to FIG. 8A, in the forwarding destination information, there is a call from UE2 with identifier "xxx-xxxx-xxxx", and the same session start request is received at 502. ” to the destination “TAS”.

Here, whether or not the session start request received at 502 and the session start request received at 508 are the same session establishment request depends on the combination of the caller and the called party included in the session start request, The session IDs can be compared and a determination can be made based on whether they match.

Therefore, the CSCF 13a transfers the session start request to the TAS 8a according to the transfer destination information (509), performs predetermined processing such as call transfer, and receives the session start request from the TAS 8a (510). Forward the request (511).

The CSCF 13b that has received the session initiation request transmits a session initiation request to the TAS 8b in the same manner as the non-interception target users because the destination UE 3 connected to the access/packet network 5b corresponding to the CSCF 13b is not the interception target user (512). , the session initiation request received from the TAS 8b to the destination UE 3 via the GW 6b (513).

Subsequently, the receiving side UE 3 transmits a response to the session initiation request (session initiation request response) to the CSCF 13b (514), and similarly to the session initiation request response from the non-interception target user, transmits a response to the originating side CSCF 13a ( 515, 516). A session initiation request response is also called a 183 session progress response indicating that a session is in progress.

The CSCF 13a that has received the session initiation request response forwards the session initiation request response to the TAS 8a for the first time so as to follow the same route as the session initiation request in reverse (518), and the session initiation request response received from the TAS 8a is sent to the interception server. 11 (519, 520), and when the interception server 11 receives the updated session initiation request response (521, 522), the session initiation request response received from the interception server 11 is transferred to the originating UE 2 (523). .

Thereafter, subsequent control signals such as calls are exchanged through the same route, and the interception server 11 changes the session information. As a result, a session can be set so that a call can be made using the RTP signal via the interception server 11 (524). Therefore, the interception server 11 intercepts the RTP signal transmitted and received in the session via the interception server 11 and provides the audio signal to the interception client 4 (525).

Next, with reference to FIG. 6, the flow of control signals when the receiving side UE 3 is the terminal of the interception target user will be described. In the example of FIG. 6, the originating side UE2 is not the interception target user (for example, the identifier is zzz-zzzz-zzzz in FIG. 8), and the receiving side UE3 is the interception target user (eg, the identifier is xxxx-xxxx-xxxx in FIG. 8). Assume that there is

First, when UE2 starts call processing with UE3 as the destination in response to user input (601), UE2 transmits a session start request to CSCF 13a (602). CSCF 13a transfers the SIP signal to TAS 8a according to the transfer destination information shown in FIG. Send a session initiation request (604).

Subsequently, the CSCF 13b transfers the session initiation request to the interception server 11 based on the iFC containing the subscriber information of the UE3, that is, the transfer destination information for the interception target (605). Again, as described above, the CSCF 13b may store session start requests received within a predetermined period of time and use them to compare session start requests for identity, which will be described later. Subsequently, the CSCF 13b, which has transmitted/received the session start request to/from the TAS 8b (606), transfers the SIP signal to the interception server according to the iFC settings (607, 608).

The interception server 11 updates the information used for session establishment included in the session start request (609), and starts interception processing (610). Note that the interception server 11 updates the session start request so that the sender, the called party, and the session ID of the received session start request are not changed. As a result, in the routing of the CSCF 13b, which will be described later, it is possible to determine that the session start request before the update by the interception server 11 and the session start request after the update are the same session start request. It also transfers the updated session initiation request to the CSCF 13b (612). The CSCF 13b transmits the received session initiation request to the destination UE 3 via the GW 6b (613).

When the destination UE 3 transmits a session start request response to the session start request to the CSCF 13b (614), the CSCF 13b transfers the session start request response to the interception server 11 so as to follow the same path as the session start request in reverse (615). , 616), when the interception server 11 receives the updated session initiation request response (617, 618), it transfers the session initiation request response to the TAS 8b (619, 620).

In the subsequent processing, CSCF 13b transmits a session start request response to CSCF 13a (621), CSCF 13a transmits/receives the session start request response to/from TAS 8a (622), and transmits the session start request response to destination UE 2 (623). Thereafter, SIP signals such as a predetermined call are exchanged (not shown), and when a session is established, a call is started with an RTP signal via interception server 11 (624). The interception server 11 provides the voice data to the interception client 4 (625). It should be noted that upon receiving a reception response (also called a 200 (INVITE) signal), which is a control signal following the session start request, the interception server 11 receives an interception signal containing the originating side identifier and the called side identifier via the interception client NW20. A start notification may be sent to the interception client 4 (not shown).

<When disconnecting/holding/releasing a session>
Next, the flow of the SIP signal at the time of disconnection when the originating UE 2 is the terminal of the interception target user will be described with reference to FIG. When the originating UE 2 issues a disconnection instruction by a user operation or the like (1001), a disconnection request is transmitted from the originating UE 2 (1002). A disconnect request is also called a BYE request. The disconnection request is sent to interception server 11 at 1002-1004 in the same manner as the session start request shown at 502-505 in FIG. Upon receiving the disconnection request, the interception server 11 ends the interception process (1005) and notifies that the interception has ended (1006). In the interception end notification, information including at least one of, for example, the identifier of the terminating UE 2, the identifier of the calling UE 3, the call duration, and the call end time is sent to the interception client 4. FIG. In FIG. 10, the case where the caller UE 2 transmits a disconnection request has been described as an example. The server 11 can terminate the interception process. Also, in 1007 to 1012, a disconnection request is transmitted to the receiving side UE 3 through the same route as 508, 510 to 513 in FIG.

Next, with reference to FIG. 11, the flow of SIP signals at the time of starting hold and canceling hold when the originating UE 2 is the terminal of the interception target user will be described.

When UE2 and 3 transmit and receive RTP signals at 1101 and interception server 11 provides the RTP signals to interception client 4 (1102), UE2 or 3 may receive a call hold instruction by user operation. In FIG. 11, it is assumed that the originating side UE2 has received a hold instruction. Since RTP signals are not exchanged while the call is on hold, the interception server 11 stops the interception process and notifies the interception client 4 that the call has changed to the hold state. The flow of control signals in such a case will be described.

The UE2 that has received the hold instruction transmits a hold request to the CSCF 13a (1104). A hold request is also called a re-INVITE (Hold) signal. The pending request is also forwarded to the interception server 11 at 1104-1107 like other SIP signals. The processing of 1104-1107 transfers the pending request so as to follow the route similar to 502 and 504 in FIG.

Upon receiving the hold request, the interception server 11 stores call information indicating that the call intercepted in 1101 is on hold (1108), and stops the interception process (1109). Also, when the interception process is stopped, the interception client 4 is notified of the interception process (1110). The notification of the suspension of the interception process includes the identifier of the originating UE 2, the identifier of the terminating UE 3, the time when the interception process was stopped, the call duration until the hold, and the information indicating which of the originating and terminating UEs issued the hold instruction. including at least one of In 1111 to 1116, a hold request is transmitted to the destination UE 3 through the same route as 508, 510 to 513 in FIG. Since the subsequent flow of response to the hold request is the same as the session start request flow 514 to 523 in FIG. 5, description thereof will be omitted.

In this way, by stopping the interception while on hold, it is possible to avoid sending unnecessary voice data to the interception client 4 .

After that, the UE 2 may receive an instruction to cancel the hold by a user's operation. In this case, since the call is resumed, the interception server 11 resumes interception and notifies the interception client 4 that the call has changed from the hold state to the call state. The flow of control signals in such a case will be described with reference to 1151-1166.

After the hold is started, when the UE 2 receives a hold release instruction by user operation (1151), a hold release request is transmitted to the interception server 11 in the same manner as the hold request (1152-1155). An unhold request is also called a re-INVITE (Unhold) signal.

When the interception server 11 receives the hold release request, it checks whether there is call information stored as a hold state (1156). The interception client 4 is notified of the resumption of processing (1158). The interception processing resumption notification includes at least one of information indicating the identifier of the originating UE2, the identifier of the terminating UE3, the time when the interception processing was restarted, and the length of the pending state (holding time). . In 1159-1164, a hold release request is transmitted to the receiving side UE3 through the same route as 508, 510-513 in FIG. The subsequent flow of responses to the hold release request is the same as the flow of session start requests 514 to 523 in FIG. 5, so description thereof will be omitted.

Subsequently, when the hold is released and the call resumes (1165), interception is resumed and the intercepted RTP signal is provided to the interception client 4 (1166).

As a result, interception can be performed without exception from the time the hold is released.

<Processing flow>
Next, the start of interception processing accompanying the start of a session executed by the interception system 10 will be described with reference to FIG. The processing of S701 to S704 and S706 to S708 shown in FIG. 7 is realized by the processor of the control unit 131 of the CSCF 13a executing the program stored in the memory. The processing shown in FIG. 7 is started when the CSCF 13a receives a session initiation request (S701). The processing of S705 is implemented by the processor of the control unit 111 of the interception server 11 executing the program stored in the memory.

First, in S702, the CSCF 13a uses the transfer destination information for the interception target as shown in FIG. It is determined whether to use transfer destination information for non-interception targets as shown in (B). If it is determined that the forwarding destination information for non-intercepting target is to be used (non-intercepting target in S702), the process proceeds to S708, and the session start request is transferred to TAS according to the forwarding destination information of the non-intercepting target user, and the processing of FIG. 7 is performed. exit.

If the session to be established by the session start request includes the interception target user and it is determined that the transfer destination information for the interception target user is to be used (for interception in S702), the CSCF 13a advances the process to S703, and Determine if a start request has already been received. The determination in S703 of whether or not the session start requests are the same may be performed by determining whether or not the combination of the calling address and the called address match, as described above, or by determining whether the session IDs match. It may be determined whether

If it is determined that a session start request for an unestablished session has not yet been received, that is, a new session start request has been received (No in S703), the CSCF 13a advances the process to S704, and obtains transfer destination information for the interception target user. , the session initiation request is transferred to the transfer destination (the interception server 11 in the example of FIG. 8A) whose reference order is "1". As a result, interception processing can be started by the interception server 11 in S705. Subsequently, the CSCF 13a advances the process to S706 and ends the session initiation request storage process.

If the same session start request has already been received in S703, the CSCF 13a advances the process to S707, and the transfer destination information for the interception target user whose reference order is "2" (example in FIG. 8A). Then transfer the session start request to TAS).

In the example of FIG. 7, the processing executed by the CSCF 13a on the originating side has been described. A session start request is sent to Therefore, the processing of S705 is executed after S707. In other words, the process S705 executed by the interception server 11 may be executed when the interception server 11 receives the session start request, and the timing is not limited.

As described above, according to the communication interception system according to the present embodiment, when the CSCF 13 identifies the identifier of the interception target user and receives the session start request, the identifier of the interception target user is included, If it is determined that the session start request satisfies a predetermined condition, the session start request is transferred to the interception server 11 . As a result, the interception server 11 updates and sends back the session start request, thereby establishing a session in which the interception target user is included so that the session communicates via the interception server 11, and intercepts the communication in the session. be able to. Since interception can be performed from the establishment of a session, it is possible to intercept all communications by interception target users.

<Management processing of interception target user information>
Next, with reference to FIG. 12, an example of processing for managing information about interception target users will be described.

In S<b>1201 , the maintenance device 15 transmits transfer destination information including the identifier of the interception target user to the HSS 12 via the maintenance NW 14 . As an example, the maintenance device 15 may have an input reception unit, and an administrator of the interception system 10 may input to the maintenance device 15 via the input reception unit.

The HSS 12, which receives the transfer destination information including the identifier of the interception target user from the maintenance device 15, can store the information in the storage unit 122 of the HSS 12 (S1202). If the CSCF 13 can interpret and transfer the subscriber information (iFC), the subscriber information (iFC) and transfer destination information may be the same. If the CSCF 13 can interpret and transfer the iFC information, the iFC information and the transfer destination information may be the same. Subsequently, the CSCF 13 downloads the transfer destination information from the HSS 12 in response to receiving the instruction to download the transfer destination information from the HSS 12 (S1203). In this embodiment, the CSCF 13 immediately acquires the iFC including the forwarding destination information in the form of notification from the HSS 12, but it may be configured to periodically acquire the iFC from the HSS 12. FIG. In one example, the maintenance device 15 may transmit update instructions to the HSS 12 at predetermined time intervals. Subsequently, the HSS 12 stores the received transfer destination information in the storage unit 122 and uses it for transfer of the control signal. By obtaining the iFC for interception, the CSCF 13 can transfer the call to the interception server 11 and provide interception information to the client.

As a result, the system administrator or maintenance operator can instruct the addition/deletion of interception target users during the operation of the interception system 10 from the maintenance device 15, and the convenience of the interception system 10 can be improved. .

<Other embodiments>
The invention is not limited to the above embodiments, and various modifications and changes are possible within the scope of the invention.

For example, in the present embodiment, the CSCF 13 determines the transfer destination of the received session start request according to the number of times the session start request for the same unestablished session is received. However, CSCF 13 transfers the session initiation request to the interception server when the received session initiation request is received from GW 6 or another CSCF, and when it is received from the interception server, GW 6 or another CSCF receives the session initiation request. Rules may be defined to forward to a different network node than the interception server, such as CSCF. That is, the CSCF 13 only needs to transfer the session start request to the interception server 11 when the unestablished session start request satisfies the predetermined conditions, and the transfer rule can be changed according to the settings of the transfer destination information shown in FIG. can.

In such a case, the forwarding destination information may be associated with the identifier, direction, destination, and network node of the receiving source. That is, the forwarding destination information shown in FIGS. 8A and 8B is merely an example, and can be changed as appropriate according to the forwarding rules.

Further, in this embodiment, the CSCF corresponding to the access/packet network to which the UE of the interception target user is connected transfers the session initiation request to the interception server. In one example, the CSCF on the calling side may be configured to transfer the session start request to the interception server 11 regardless of whether the user to be intercepted is the calling side or the called side. Alternatively, the CSCF on the terminating side may transfer the session start request to the interception server 11 regardless of whether the user to be intercepted is the originating side or the terminating side. That is, any CSCF 13 of the communication system 1 may transfer the session initiation request to the interception server 11 .

Also, in the present embodiment, the interception system 10 has been described as being applied to a Voice over LTE (VoLTE) network, but it can also be applied to call services using similar CSCF and subscriber information system.

1: communication system, 2: originating UE, 3: destination UE, 4: interception client, 10: interception system, 11: interception server, 12: HSS, 13: CSCF

In order to achieve the above object, a communication interception system according to one aspect of the present invention includes:
A communication interception system comprising a communication interception device and a communication control device,
The communication control device is
Acquisition means for acquiring information capable of identifying an identifier of an interception target user;
receiving means for receiving a session initiation request requesting establishment of a session;
When the received session initiation request includes the identifier obtained by the obtaining means,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer means;
with
The communication interception device is
session establishment means for establishing a session so that communication is performed via the communication interception device when the session start request is received;
interception means for intercepting communication in the session established by the session establishment means;
a notification means for sending notification of interception;
with
The interception means stops interception when the communication interception device receives a request to start holding the session, and resumes interception when the communication interception device receives a request to cancel the hold of the session,
The notifying means is characterized in that, when the interception is resumed, information indicating the length of time the session has been in the pending state is notified .

Further, in order to achieve the above object, a communication interception device according to an aspect of the present invention includes:
A communication interception device,
Updating session description protocol information included in the session initiation request so that communication is performed via the communication interception device when the session initiation request is received from another network node, and the updated session initiation request. to the other network node; and
an interception means for intercepting communications in a session via the communication interception device;
a notification means for sending notification of interception;
with
The interception means stops interception when the communication interception device receives a request to start holding the session, and resumes interception when the communication interception device receives a request to cancel the hold of the session,
The notifying means is characterized in that, when the interception is resumed, information indicating the length of time the session has been in the pending state is notified .

Further, in order to achieve the above object, a communication interception method according to an aspect of the present invention includes:
A communication interception method for a communication interception system comprising a communication interception device and a communication control device,
an acquisition step in which the communication control device acquires information capable of specifying an identifier of an interception target user;
a receiving step for receiving a session initiation request requesting establishment of a session;
When the session initiation request received by the communication control device includes the identifier obtained in the obtaining step,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer step;
a session establishment step of establishing a session so that communication is performed via the communication interception device when the communication interception device receives the session initiation request;
an interception step in which the communication interception device intercepts communications in the session established in the session establishment step;
a notification step of sending a notification of the interception;
with
In the interception step, the communication interception device stops interception when receiving a request to start holding the session, and resumes interception when receiving a request to cancel the hold of the session;
In the notifying step, the communication interception device notifies information indicating the length of time that the session has been held when the interception is resumed .

Further, in order to achieve the above object, a communication interception method according to an aspect of the present invention includes:
A communication interception method for a communication interception device,
Updating session description protocol information included in the session initiation request so that communication is performed via the communication interception device when the session initiation request is received from another network node, and the updated session initiation request. to the other network node; and
an interception step of intercepting communications in a session via the communication interception device;
a notification step of sending a notification of the interception;
including
In the interception step, the communication interception device stops interception when receiving a request to start holding the session, and resumes interception when receiving a request to cancel the hold of the session;
In the notifying step, the communication interception device notifies information indicating the length of time that the session has been held when the interception is resumed .

Further, in order to achieve the above object, a program according to one aspect of the present invention includes:
In the computer of the communication interception device,
Updating session description protocol information included in the session initiation request so that communication is performed via the communication interception device when the session initiation request is received from another network node, and the updated session initiation request. to the other network node; and
an interception step of intercepting communications in a session via the communications interception device;
a notification step of sending a notification of the interception;
and
In the interception step, the communication interception device stops interception when receiving a request to start holding the session, and resumes interception when receiving a request to cancel the hold of the session;
In the notifying step, the communication interception device notifies information indicating the length of time that the session has been held when the interception is resumed .

Further, in order to achieve the above object, a program according to one aspect of the present invention includes:
A communication interception system comprising a communication interception device and a communication control device,
an acquisition step in which the communication control device acquires information capable of specifying an identifier of an interception target user;
a receiving step for receiving a session initiation request requesting establishment of a session;
When the session initiation request received by the communication control device includes the identifier obtained in the obtaining step,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer step;
a session establishment step of establishing a session so that communication is performed via the communication interception device when the communication interception device receives the session initiation request;
an interception step in which the communication interception device intercepts communications in the session established in the session establishment step;
a notification step in which the communication interception device transmits a notification regarding the interception;
and
In the interception step, the communication interception device stops interception when receiving a request to start holding the session, and resumes interception when receiving a request to cancel the hold of the session;
In the notifying step, the communication interception device notifies information indicating the length of time that the session has been held when the interception is resumed .

In order to achieve the above object, a communication interception system according to one aspect of the present invention includes:
A communication interception system for an IP Multimedia Service (IMS) network comprising a communication interception device and a communication control device,
The communication control device is
Acquisition means for acquiring information capable of identifying an identifier of an interception target user;
receiving means for receiving a session initiation request requesting establishment of a session;
When the received session initiation request includes the identifier obtained by the obtaining means,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer means;
with
The communication interception device is
session establishment means for establishing a session so that communication is performed via the communication interception device when the session start request is received;
interception means for intercepting communication in the session established by the session establishment means;
a notification means for sending notification of interception;
with
The receiving means receives a request to start holding the session,
When the transfer means receives the pending start request including the identifier obtained by the obtaining means,
transferring the hold start request to the communication interception device when it is determined that the received hold start request satisfies the predetermined condition;
forwarding the hold start request to a network node different from the communication interception device when determining that the received hold start request does not satisfy the predetermined condition;
The interception means stops interception when the communication interception device receives a request to start holding the session, and resumes interception when the communication interception device receives a request to cancel the hold of the session,
The notification means is characterized in that, when the interception is resumed, information indicating the length of time that the session has been in the pending state is notified.

Further, in order to achieve the above object, a communication interception device according to an aspect of the present invention includes:
A communication interception device for an IP Multimedia Service (IMS) network , comprising:
Updating session description protocol information included in the session initiation request so that communication is performed through the communication interception device when the session initiation request is received from another network node in the IMS network ; forwarding means for forwarding the session start request received from the server to the other network node;
an interception means for intercepting communications in a session via the communication interception device;
a notification means for sending notification of interception;
with
The interception means stops interception when the communication interception device receives a request to start holding the session forwarded from another network node in the IMS network, and the communication interception device resuming interception upon receiving a release request for said session forwarded from another network node ;
The notifying means is characterized in that, when the interception is resumed, information indicating the length of time the session has been in the pending state is notified.

Further, in order to achieve the above object, a communication interception method according to an aspect of the present invention includes:
A communication interception method for a communication interception system of an IP Multimedia Service (IMS) network comprising a communication interception device and a communication control device, comprising:
an acquisition step in which the communication control device acquires information capable of specifying an identifier of an interception target user;
a receiving step for receiving a session initiation request requesting establishment of a session;
When the session initiation request received by the communication control device includes the identifier obtained in the obtaining step,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer step;
a session establishment step of establishing a session so that communication is performed via the communication interception device when the communication interception device receives the session initiation request;
an interception step in which the communication interception device intercepts communications in the session established in the session establishment step;
a notification step of sending a notification of the interception;
with
In the interception step, the communication control device receives a request to start holding the session, and the received request to start holding the session includes the identifier obtained in the obtaining step,
transferring the hold start request to the communication interception device when it is determined that the received hold start request satisfies the predetermined condition;
forwarding the hold start request to a network node different from the communication interception device when determining that the received hold start request does not satisfy the predetermined condition;
In the interception step, the communication interception device stops interception when receiving a request to start holding the session, and resumes interception when receiving a request to cancel the hold of the session;
In the notifying step, the communication interception device notifies information indicating the length of time that the session has been held when the interception is resumed.

Further, in order to achieve the above object, a communication interception method according to an aspect of the present invention includes:
A communication interception method for a communication interception device in an IP Multimedia Service (IMS) network , comprising:
Updating session description protocol information included in the session initiation request so that communication is performed via the communication interception device when the session initiation request is received from another network node, and the updated session initiation request. to the other network node; and
an interception step of intercepting communications in a session via the communication interception device;
a notification step of sending a notification of the interception;
including
In the interception step, the communication interception device stops interception when receiving the session hold initiation request forwarded from another network node of the IMS network, and resumes interception upon receipt of a request to release said hold for said session,
In the notifying step, the communication interception device notifies information indicating the length of time that the session has been held when the interception is resumed.

Further, in order to achieve the above object, a program according to one aspect of the present invention includes:
To the computer of the wiretapping device of the IP Multimedia Service (IMS) network ,
Updating session description protocol information included in the session initiation request so that communication is performed via the communication interception device when the session initiation request is received from another network node, and the updated session initiation request. to the other network node; and
an interception step of intercepting communications in a session via the communications interception device;
a notification step of sending a notification of the interception;
and
In the interception step, the communication interception device stops interception when receiving a request to initiate a hold of the session from another network node of the IMS network, and the hold of the session from another network node of the IMS network. Resumes interception when it receives a request to cancel the
In the notifying step, the communication interception device notifies information indicating the length of time that the session has been held when the interception is resumed.

Further, in order to achieve the above object, a program according to one aspect of the present invention includes:
A communication interception system for an IP Multimedia Service (IMS) network comprising a communication interception device and a communication control device,
an acquisition step in which the communication control device acquires information capable of specifying an identifier of an interception target user;
a receiving step for receiving a session initiation request requesting establishment of a session;
When the session initiation request received by the communication control device includes the identifier obtained in the obtaining step,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer step;
a session establishment step of establishing a session so that communication is performed via the communication interception device when the communication interception device receives the session initiation request;
an interception step in which the communication interception device intercepts communications in the session established in the session establishment step;
a notification step in which the communication interception device transmits a notification regarding the interception;
and
In the interception step, the communication control device receives a request to start holding the session, and the received request to start holding the session includes the identifier obtained in the obtaining step,
transferring the hold start request to the communication interception device when it is determined that the received hold start request satisfies the predetermined condition;
forwarding the hold start request to a network node different from the communication interception device when determining that the received hold start request does not satisfy the predetermined condition;
In the interception step, the communication interception device stops interception when receiving a request to start holding the session, and resumes interception when receiving a request to cancel the hold of the session;
In the notifying step, the communication interception device notifies information indicating the length of time that the session has been held when the interception is resumed.

Claims (14)

A communication interception system comprising a communication interception device and a communication control device,
The communication control device is
Acquisition means for acquiring information capable of identifying an identifier of an interception target user;
receiving means for receiving a session initiation request requesting establishment of a session;
When the received session initiation request includes the identifier obtained by the obtaining means,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer means;
with
The communication interception device is
session establishment means for establishing a session so that communication is performed via the communication interception device when the session initiation request is received;
interception means for intercepting communication in the session established by the session establishment means;
A communication interception system comprising: 2. A session start request according to claim 1, wherein said predetermined condition is that said session start request is a session between the same two terminals and is the first received session start request for an unestablished session. communications interception system. 2. The predetermined condition is that the session initiation request is a session between the same two terminals and is a session initiation request received from the communication interception device for an unestablished session. Or the communication interception system according to 2. 4. The session establishing means according to any one of claims 1 to 3, wherein said session establishment means updates session description protocol information included in said session initiation request and transmits said updated session initiation request to said communication control device. A communications interception system as described in paragraph. 5. The apparatus according to any one of claims 1 to 4, wherein said acquisition means receives, as said information, information in which said identifier is associated with transfer destination information specifying a transfer destination of said session start request from another device. A communication interception system according to any one of claims 1 to 3. 6. The communication interception system according to claim 1, wherein said communication interception device comprises notification means for notifying that said interception means has started interception of communications. 7. The communication interception system according to claim 6, wherein said notification means notifies that interception of communications has ended when said session through said communication interception device is terminated. The interception means stops interception when the communication interception device receives a request to start holding the session, and starts interception when the communication interception device receives a request to cancel the hold of the session. The communication interception system according to any one of claims 1 to 7, characterized by: 9. The communication interception system according to any one of claims 1 to 8, further comprising transmission means for transmitting voice data when communication intercepted by said interception means includes voice data. A communication interception device,
Updating session description protocol information included in the session initiation request so that communication is performed via the communication interception device when the session initiation request is received from another network node, and the updated session initiation request. to the other network node; and
an interception means for intercepting communications in a session via the communication interception device;
A communication interception device comprising: A communication interception method for a communication interception system comprising a communication interception device and a communication control device,
an acquisition step in which the communication control device acquires information capable of specifying an identifier of an interception target user;
a receiving step for receiving a session initiation request requesting establishment of a session;
When the session initiation request received by the communication control device includes the identifier obtained in the obtaining step,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer step;
a session establishment step of establishing a session so that communication is performed via the communication interception device when the communication interception device receives the session initiation request;
an interception step in which the communication interception device intercepts communications in the session established in the session establishment step;
A communication interception method comprising: A communication interception method for a communication interception device,
Updating session description protocol information included in the session initiation request so that communication is performed via the communication interception device when the session initiation request is received from another network node, and the updated session initiation request. to the other network node; and
an interception step of intercepting communications in a session via the communication interception device;
A communication interception method comprising: In the computer of the communication interception device,
Updating session description protocol information included in the session initiation request so that communication is performed via the communication interception device when the session initiation request is received from another network node, and the updated session initiation request. to the other network node; and
an interception step of intercepting communications in a session via the communications interception device;
A program characterized by causing the execution of A communication interception system comprising a communication interception device and a communication control device,
an acquisition step in which the communication control device acquires information capable of specifying an identifier of an interception target user;
a receiving step for receiving a session initiation request requesting establishment of a session;
When the session initiation request received by the communication control device includes the identifier obtained in the obtaining step,
transferring the session start request to the communication interception device when it is determined that the session start request satisfies a predetermined condition;
forwarding the session start request to a network node different from the communication interception device when it is determined that the session start request does not satisfy the predetermined condition;
a transfer step;
a session establishment step of establishing a session so that communication is performed via the communication interception device when the communication interception device receives the session initiation request;
an interception step in which the communication interception device intercepts communications in the session established in the session establishment step;
A program characterized by causing the execution of

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