JP5193956B2 - IP network system and method for changing communication destination thereof - Google Patents

Description

  The present invention relates to an IP (Internet Protocol) network that implements a voice communication service using a session control protocol such as SIP (Session Initiation Protocol), and a communication destination changing method used in this system.

  A standardization organization such as TISPAN defines a voice communication service using a management type IP network such as NGN (Next Generation Network). In a managed IP network (packet network), in order to realize a voice communication service similar to the conventional circuit switching type, communication quality is secured (bandwidth control, etc.) and media between terminals using a session control protocol such as SIP. Flow settings are made.

  By the way, also in the voice communication service using such a management type IP network, it is required to realize an additional service with voice guidance as in the case of the circuit switching type voice communication. This type of additional service, for example, first transmits a voice guidance to the calling communication terminal to notify the caller of information related to the communication fee, and after the caller confirms this information, The terminal is connected to the communication terminal on the called side to enable voice communication between both terminals.

  In order to realize this type of supplementary service, for example, according to a session probability request from the originating communication terminal, a session is first established between the originating communication terminal and the guidance server. Establish a media flow for voice communication by establishing. Next, the session is changed between the communication terminal on the caller side and the communication terminal on the callee side, so that voice communication between the two communication terminals is enabled thereafter (for example, see Non-Patent Document 1). reference.).

ETSI ES 282 003 V3.3.1 (2009-03): Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); Resource and Admission Control Sub-System (RACS): Functional Architecture

  However, in the above-mentioned conventionally proposed method, if the destination of communication is changed while maintaining the session, the media information and status are not retained in the session control server, or the communication destination cannot be changed. Therefore, complicated processing such as building a so-called rollback mechanism to return to the media flow is required.

  The present invention has been made paying attention to the above circumstances, and an object of the present invention is to provide an IP network system and a communication destination changing method thereof capable of changing the media flow by a simple process.

In order to achieve the above object, one aspect of the present invention provides an IP network in which a guidance device connected to an IP network independently of a communication terminal executes a voice communication service using a session control protocol using the IP network. The system includes the following components. That is, when voice guidance information is transmitted from the guidance device to the calling communication terminal using the first session, the communication destination of the calling communication terminal is changed from the guidance device to the receiving communication terminal. In addition, after the guidance information has been transmitted, the guidance device transmits a request for terminating the first session to which the token has been added to the communication terminal on the transmission side, and is added to the request for terminating the first session. A request for establishing a second session with the same token as the token to be transmitted is transmitted to the communication terminal on the originating side. On the other hand, when the communication terminal on the originating side receives the end request for the first session, the second token with the same token added to the end request for the first session is added. The voice communication state of the first session is suspended until a session establishment request is received. When the second session establishment request with the same token added as the token added to the first session termination request is received, the hold state is released, and the second session is released. Is returned to the guidance device. In addition, when the guidance device receives the establishment response for the second session returned from the communication terminal on the originating side, the guidance device issues an establishment request for the third session associated with the second session. It is intended to transmit to the communication terminal.

  Therefore, when the communication destination of the calling communication terminal is changed from the guidance device to the receiving communication terminal, the first session used to transmit the guidance information is once terminated and a second second session is newly established. Used for voice communication between terminals. For this reason, it is necessary to change the communication destination while maintaining the same session. If the session control server on the IP network holds the media information or status, or the communication destination cannot be changed, it is changed. Complex processing such as constructing a so-called rollback mechanism for returning to the previous media flow becomes unnecessary.

  In addition, a token is issued at the end of the first session, and this token is added to the new second session establishment request and transmitted. Therefore, the communication terminal on the transmission side uses the token to renew the old first session and the new one. Thus, it is possible to accurately determine which new session should cancel the voice communication hold state. That is, it becomes possible to accurately take over between sessions.

Another aspect of the present invention is characterized by comprising the following embodiments.
In the first embodiment, after the transmission of the guidance information is completed, a request for terminating the first session to which a token is added is first transmitted to the originating communication terminal, and the first session is released by the IP network. Thereafter, a request for establishing a second session to which the same token as the token added to the request for terminating the first session is added is transmitted to the communication terminal on the originating side.
In this way, in the IP network, after the first session is released, a new second session is established. This avoids a situation in which the communication band of the voice guidance media stream and the communication band of the call media stream are simultaneously secured on the IP network. Therefore, it is possible to secure communication resources even when the communication bandwidth of the IP network is limited.

In the second embodiment, when the guidance device issues a token, a unique token is issued in the IP network.
In this way, the communication terminal on the transmission side can always reliably associate the old first session and the new second session.

In the third embodiment, when a control server installed in the IP network receives a second session establishment request with the same token added as the token added to the first session termination request, The accounting process is executed by regarding the communication by the first session and the communication by the second session as communication by the same session.
In this way, the control server does not misinterpret the communication by the new second session as the new communication, thereby preventing erroneous billing processing from being executed.

  That is, according to the present invention, it is possible to provide an IP network system and a communication destination changing method thereof that can change the communication destination by simple processing.

1 is a schematic configuration diagram of an IP network system according to an embodiment of the present invention. It is a block diagram which shows the function structure of the guidance server used with the system shown in FIG. It is a block diagram which shows the function structure of the communication terminal used with the system shown in FIG. It is a sequence diagram which shows the procedure and processing content of the communication destination change process in the system shown in FIG.

Embodiments according to the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an IP network system according to an embodiment of the present invention. In this system, a control server 401 is connected to a management type IP network NW such as NGN, and a guidance server 301 is connected via a forwarding node 202. Then, under session control by the control server 401, a media flow is constructed between the terminals 101 and 102, thereby providing a voice communication service with voice guidance to the terminals 101 and 102. . Terminals 101 and 102 are connected to IP network NW via forwarding nodes 201 and 203, respectively. In FIG. 1, for convenience of explanation, the forwarding nodes 201 to 203 are described as components independent of the IP network NW, but the forwarding nodes 201 to 203 may be included in the IP network NW.

  The control server 401 performs network control, charging control, and the like according to a session control protocol such as SIP. Network control includes session establishment and disconnection processing, securing of a necessary communication band for the transfer nodes 201 to 203, and release processing thereof. The forwarding nodes 201 to 203 are configured by routers, switches, and gateways, for example.

By the way, the guidance server 301 is configured as follows. FIG. 2 is a block diagram showing the functional configuration.
That is, the guidance server 301 includes a main control unit 3011, a communication interface unit 3012, a session control unit 3013, a guidance voice transmission unit 3014, a storage unit 3015, and a token issue unit 3016. Of these blocks, the functions of each block excluding the storage unit 3015 are realized by causing a central processing unit (CPU) to execute a program.

  The communication interface unit 3012 performs transmission / reception of control data related to session control and transmission of a voice guidance message. Under the control of the main control unit 3011, the session control unit 3013 controls transmission / reception of a session establishment request and session termination request and transmission / reception of a session establishment response and session termination response according to the session control protocol.

A voice guidance message corresponding to the type of voice guidance service is stored in the storage unit 3015 in advance. For example, voice guidance messages for free dials and navigation dials are stored. The guidance voice transmission unit 3014 selectively reads out the voice guidance message corresponding to the requested voice guidance service from the storage unit 3015 under the control of the main control unit 3011, and reads the read voice guidance message as described above. Transmission is performed from the communication interface unit 3012 to the terminal on the transmission side.
A token issuing unit 3016 issues a token in accordance with an instruction from the main control unit 3011. A code is set so that this token is unique in the IP network NW.

The main control unit 3011 has the following functions as control functions according to the present invention.
(1) A function of transmitting a voice guidance message from the guidance voice transmitting unit 3014 in a state where a media flow is set up with the calling terminal in response to a session establishment request from the calling terminal.
(2) A function of causing the token issuing unit 3016 to issue a token after the transmission of the voice guidance message is completed, and causing the session control unit 3013 to transmit a session end request to the originating terminal.
(3) A function that, after transmitting the session end request, transmits a new session establishment request with the same token as the token added to the session end request from the session control unit 3013 to the originating terminal.
(4) When a session establishment response to the new session establishment request is received by the session control unit 3013, a session establishment request using the same session ID as the session ID used in the new session establishment request is A function of transmitting from the session control unit 3013 to the terminal on the receiving side.

On the other hand, the terminals 101 and 102 are each composed of a fixed telephone or a mobile telephone having a SIP function and configured as follows. FIG. 3 is a block diagram showing the functional configuration. Since the terminals 101 and 102 have the same configuration, only the terminal 101 will be described here.
That is, the terminal 101 includes a main control unit 1011, a communication interface unit 1012, a session control unit 1013, a voice transmission / reception unit 1014, a hold control unit 1015, a token verification unit 1016, and an input / output interface unit 1017. The voice interface unit 1010 is provided.

  The communication interface unit 1012 performs transmission / reception of control data related to session control and transmission of voice call data with the IP network NW. Under the control of the main control unit 1011, the session control unit 1013 controls transmission / reception of a session establishment request and session termination request and transmission / reception of a session establishment response and session termination response according to the session control protocol. The voice transmission / reception unit 1014 has, for example, a voice codec, and performs coding / decoding processing of voice call data.

  When a session end request to which a token is added is received, the token verification unit 1016 stores the token added to the session end request. When a new session establishment request with a token added is received, the token added to the new session establishment request is collated with the stored token, and the collation result is sent to the main control unit 1011. Notice. The hold control unit 1015 holds the voice communication according to the control instruction of the main control unit 1011.

  An input device 1018 and a display device 1019 are connected to the input / output interface unit 1017. The input device consists of a keyboard or a dial keypad. The display device 1019 includes a liquid crystal display. The input / output interface unit 1017 receives the operation data input from the input device 1018 and notifies the main control unit 1011 of the operation data, and causes the display device 1019 to display the display data output from the main control unit 1011. The voice interface unit 1010 includes a microphone and a speaker, and inputs a user's transmitted voice and outputs a received voice.

The main control unit 1011 has the following functions as control functions according to the present invention.
(1) A function of transmitting a session establishment request from the session control unit 1013 when the input / output interface unit 1017 is notified that a transmission operation has been performed in the input device 1018.
(2) When a media flow is set between the session establishment request and the guidance server 301, the voice transmission / reception unit 1014 and the voice interface unit 1010 are connected to receive a voice guidance message. Function to perform playback operation.
(3) Based on the token verification result by the token verification unit 1016, from the reception of the session end request with the token added to the reception of the session establishment request with the same token added as the token A function of holding the voice communication by the hold control unit 1015 during the time.

Next, the operation of the system configured as described above will be described. FIG. 4 shows the operation sequence.
Here, the terminal 101 is set as the caller side and the terminal 102 as the callee side. First, after connecting the guidance server 301 to the caller terminal 101 and transmitting the voice guidance message, the communication destination is changed to the callee terminal 102. A case where voice communication between the terminals 101 and 102 is enabled will be described as an example.

(1) Execution of session establishment procedure for voice guidance service
The terminal 101 transmits a session establishment request in which the session ID (SID) is set to 1 for the communication connection service to the terminal 102. At this time, the address of the terminal 102 when using the voice guidance service is designated as the destination address. For example, in the case of a telephone number, a free dial or navigation dial number is designated instead of a normal telephone number. In the case of SIP, the destination address is inserted into the SIP URI of the To header in the INVITE message. The session establishment request is transferred to the guidance server 301 via the control server 401 as shown in FIG. At this time, the control server 401 reserves a communication band for the transfer nodes 201 and 202, thereby securing communication resources.

  Upon receiving the session establishment request, the guidance server 301 constructs a media flow for the terminal 101 on the transmission side, and returns a session establishment response (SID = 1) to the control server 401. The control server 401 sets the media flow between the terminal 101 on the transmission side and the guidance server 301 using the communication resources previously secured for the transfer nodes 201 and 202. Then, the session establishment response (SID = 1) is transferred to the terminal 101 on the transmission side.

  Thus, the media flow from the terminal 101 on the transmission side to the guidance server 301 is completed, and then a voice guidance message is sent from the guidance server 301 to the terminal 101 on the transmission side. As a voice guidance message, for example, in the case of Navi Dial, “Connect with Navi Dial. This call can be used with a call charge of approximately XX yen every ○ second” is used.

(2) Execution Procedure for Ending Voice Guidance Session When the guidance server 301 ends transmission of a preset guidance message and completes necessary charging processing, etc., the procedure for terminating the voice guidance session is completed. Is executed as follows.
That is, the guidance server 301 first issues a token XXX as shown in FIG. At this time, the token XXX is set to be unique in the IP network NW. The guidance server 301 generates a session end request (SID = 1) to which the token XXX is added, and transmits the session end request (SID = 1) to which the token XXX is added to the terminal 101 on the transmission side. This session end request (SID = 1) is transferred to the terminal 101 on the transmission side via the control server 401. At this time, when the control server 401 receives the session termination request (SID = 1), the control server 401 disconnects the media flow related to the session to the transfer servers 201 and 202, discards the communication band reservation, and releases the communication resources.

  Upon receiving the session end request (SID = 1) to which the token XXX is added, the originating terminal 101 extracts and stores the token XXX added to the session end request by the token verification unit 1016, and Until the session establishment request with the same token XXX as the token XXX is received, the hold control unit 1015 holds the voice call state.

(3) Execution of a new session establishment procedure with the terminal 101 on the transmission side When the transmission of the session termination request (SID = 1) is terminated, the guidance server 301 subsequently establishes a new session as shown in FIG. A request (session ID = 2) is generated and transmitted to the terminal 101 on the transmission side. At this time, the same token XXX as the token XXX added to the session end request is added to the new session establishment request (SID = 2). The new session establishment request (SID = 2) to which the token XXX is added is transferred to the terminal 101 on the transmission side via the control server 401. At this time, the control server 401 executes network control for reserving a communication band for the transfer node 201 and securing communication resources.

  When the terminal 101 receives a new session establishment request (SID = 2) to which the token XXX is added, first, the token verification unit 1016 first adds a token added to the newly received session establishment request (SID = 2). XXX is compared with the token XXX added to the previously received session termination request. If the tokens XXX coincide with each other as a result of the collation, the hold control unit 1015 cancels the hold of the voice communication. At the same time, a media flow to the forwarding node 201 is constructed, and a session establishment response (SID = 2) is returned to the control server 401.

  When the control server 401 receives the session establishment response (SID = 2), the control server 401 uses the communication resource previously secured for the transfer node 201 to create a new medium between the terminal 101 on the transmission side and the transfer node 201. Set the flow. The session establishment response (SID = 2) is transferred to the guidance server 301.

(4) Execution of session establishment procedure with destination terminal 102 Upon receiving the session establishment response (SID = 2) returned from the originating terminal 101, the guidance server 301 receives an incoming call as shown in FIG. A session establishment request is transmitted to the terminal 102 on the side. At this time, as the session ID, the session ID = 2 used in the session establishment request transmitted to establish a new session with the originating terminal 101 described in the above (3) is used. Note that other session IDs may be used as the session ID. In this case, the session ID = 2 used in the session establishment request transmitted to the caller terminal 101 is transmitted to the callee terminal 102. The session used in the session establishment request (for example, ID = 3) is stored in association with each other. The session establishment request (SID = 2) is transferred to the receiving terminal 102 via the control server 401. At this time, the control server 401 executes network control for reserving a communication band for the transfer node 203 and securing communication resources.

  Upon receiving the session establishment request (SID = 2), the receiving terminal 102 constructs a media flow to the forwarding node 203 and returns a session establishment response (SID = 2) to the control server 401. When the session establishment response (SID = 2) is returned, the control server 401 sets a media flow between the terminal 102 and the forwarding node 203 using the communication resource previously secured to the forwarding node 203. Network control is executed. When this network control is completed, the session establishment response (SID = 2) is transferred from the control server 401 to the guidance server 301.

  Thus, a media flow is established between the caller terminal 101 and the callee terminal 102, and thereafter, voice communication is possible between the caller terminal 101 and the callee terminal 102 via this mediaflow. It becomes.

  When the control server 401 receives a new session establishment request added with the same token XXX as the token XXX added to the voice guidance session end request, the control server 401 communicates with the voice guidance session. The accounting process is performed by regarding the communication by the new session as the communication by the same session.

  As described above in detail, in this embodiment, the communication destination is changed by the following procedure. That is, after the transmission of the voice guidance message is completed, a session end request (SID = 1) with the token XXX added is first transmitted from the guidance server 301 to the originating terminal 101, and then the token added to the session end request. A new session establishment request (SID = 2) to which the same token XXX as XXX is added is transmitted. On the other hand, when receiving the session end request (SID = 1) with the token XXX added, the originating terminal 101 stores the token XXX added to the session end request (SID = 1) and also stores the token XXX. The voice communication state is suspended until a new session establishment request (SID = 2) to which the same token XXX as XXX is added is received. When a new session establishment request (SID = 2) to which the same token XXX is added is received, the hold state is released and a session establishment response (SID = 2) is returned to the guidance server 301. To do. When the guidance server 301 receives the session establishment response (SID = 2) returned from the originating terminal 101, the guidance server 301 sends a session establishment request (SID = 2) having the same session ID as the session establishment response (SID = 2). Transmission is made to the terminal 102 on the receiving side, and a media flow is set between the terminal 102 on the receiving side.

  Therefore, when the communication destination of the originating terminal 101 is changed from the guidance server 301 to the terminating terminal 102, the session used for transmitting the voice guidance message is once terminated and a new session is established instead. For this reason, the control server 401 needs to perform complicated processing such as building a so-called rollback mechanism that retains media information and status, or returns to the media flow before the change when the communication destination cannot be changed. Disappears.

  Moreover, a token XXX is issued at the end of the session, and this token XXX is notified to the originating terminal 101 added to the session termination request, and is also added to a new session establishment request and transmitted to the originating terminal 101. Therefore, the originating terminal 101 can reliably associate the old session and the new session with the token XXX, and thereby accurately determine which new session should be used to cancel the voice communication hold state. It becomes possible.

  In addition, since a session end request is first transmitted from the guidance server 301 to the calling-side terminal 101 and then a new session establishment request is transmitted, the control server 401 disconnects the voice guidance session. A new session is established. This avoids a situation in which the communication band of the voice guidance media stream and the communication band of the voice call media stream between the terminals are simultaneously secured on the IP network. Therefore, it is possible to secure communication resources even when the communication bandwidth of the IP network is limited.

  Furthermore, since the guidance server 301 issues a unique token in the IP network when issuing the token, the calling terminal 101 can more reliably associate the old session with the new session. Become.

  Further, since the control server 401 can perform the accounting process by regarding the communication by the voice guidance session and the communication by the new session as communication by the same session, the communication by the new session is misinterpreted as new communication. This prevents erroneous billing processing from being executed.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the guidance server 301 first transmits a session end request after transmission of the voice guidance message, and then transmits a new session establishment request. In other words, the old session termination procedure is executed first, and then a new session establishment procedure is executed. However, the present invention is not limited to this. For example, after executing a new session establishment procedure, it is also possible to execute an old session termination procedure. Furthermore, a procedure for establishing a session with the terminal 102 on the receiving side may be executed first, followed by a procedure for ending a session and a procedure for establishing a session with the terminal 101 on the outgoing side.

  In the above embodiment, the media flow is directly set between the caller terminal 101 and the callee terminal 102. However, the callout server 101 passes between the caller terminal 101 and the callee terminal 102 via the guidance server 301. Then, the media flow may be set. In this way, call voice data and image data transmitted between the calling-side terminal 101 and the called-side terminal 102 can be recorded in the guidance server 301. The recorded call voice data and image data can be reproduced by accessing the guidance server 301 later from the terminal.

In addition, the types, configurations, and control procedures of the guidance server and each terminal can be variously modified and implemented without departing from the gist of the present invention.
In short, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  NW: network, 101, 102 ... terminal, 201, 202, 203 ... transfer server, 301 ... guidance server, 401 ... control server, 1011 ... main control unit of terminal, 1012 ... communication interface unit of terminal, 1013 ... session of terminal Control unit, 1014 ... voice transmission / reception unit, 1015 ... hold control unit, 1016 ... token verification unit, 1017 ... input / output interface unit, 1018 ... input device, 1019 ... display device, 1010 ... voice interface unit, 3011 ... guidance server Main control unit 3012 Communication interface unit of guidance server 3013 Session control unit of guidance server 3014 Guidance voice transmission unit 3015 Storage unit 3016 Token issuing unit

Claims (8)

An IP network system for executing a voice communication service based on a session control protocol using an IP network,
A plurality of communication terminals connectable to the IP network;
A guidance device connected to the IP network independently of the plurality of communication terminals ,
The guidance device
Means for transmitting voice guidance information to the communication terminal on the calling side in a state where the first session by the IP network is established with the communication terminal on the calling side among the plurality of communication terminals;
Means for issuing a token after transmission of the guidance information;
Means for transmitting the end request for the first session to the communication terminal on the caller side with the issued token added thereto;
Means for transmitting a request for establishing a second session to the communication terminal on the originating side with the same token added as the token added to the request for terminating the first session ;
Means for transmitting a request for establishing a third session associated with the second session to a communication terminal serving as a receiving side among the plurality of communication terminals;
The communication terminal on the calling side is
When the first session termination request is received, the first session establishment request is received until the second session establishment request with the same token added to the first session termination request is received. Means for suspending the voice communication state of one session;
When a request for establishing a second session with the same token added as the token added to the request for terminating the first session is received, the pending state is canceled and the second session is established. An IP network system comprising: means for returning a response to the guidance device.   After the guidance information has been transmitted, the guidance device first transmits a request for terminating the first session to which the token has been added to the communication terminal on the originating side, and the first session is released by the IP network. And a request for establishing a second session, to which the same token as the token added to the request for terminating the first session is added, is transmitted to the communication terminal on the originating side. Item 2. The IP network system according to Item 1.   3. The IP network system according to claim 1, wherein the means for issuing a token issues a unique token within the IP network.   The IP network includes a control server that executes control for establishing and terminating the first, second, and third sessions, and the control server is the same as the token added to the termination request for the first session. When the second session establishment request with the token added is received, the accounting process is executed by regarding the communication by the first session and the communication by the second session as communication by the same session. The IP network system according to any one of claims 1 to 3, wherein A communication destination changing method used in an IP network system in which a guidance device connected to an IP network independently of a communication terminal uses the IP network to execute a voice communication service based on a session control protocol,
A process in which the guidance device transmits voice guidance information to the caller communication terminal in a state where the first session by the IP network is established with the caller communication terminal;
A process in which the guidance device transmits a request for termination of the first session to which the token is added to the communication terminal on the transmission side after transmission of the guidance information is completed;
A process in which the guidance device transmits a request for establishing a second session to which the same token as the token to be added to the request for terminating the first session is added to the communication terminal on the originating side;
When the communication terminal on the originating side receives the request for terminating the first session, establishment of the second session with the same token added as the token added to the request for terminating the first session Suspending the voice communication state of the first session until a request is received;
When the communication terminal on the originating side receives a request for establishing a second session to which the same token as the token added to the request for terminating the first session is received, the holding state is released. Returning the establishment response of the second session to the guidance device;
When the guidance device receives the second session establishment response returned from the originating communication terminal, the guidance device sends a third session establishment request associated with the second session to the incoming communication. A communication destination changing method of an IP network system, comprising: a step of transmitting to a terminal.   After the guidance information has been transmitted, the guidance device first transmits a request for terminating the first session to which the token has been added to the communication terminal on the originating side, and the first session is released by the IP network. And a request for establishing a second session, to which the same token as the token added to the request for terminating the first session is added, is transmitted to the communication terminal on the originating side. Item 6. A method for changing a communication destination of an IP network system according to Item 5.   The method for changing a communication destination of an IP network system according to claim 5 or 6, wherein the guidance device issues a unique token in the IP network.   When the IP network receives a second session establishment request with the same token added as the token added to the first session termination request, the communication by the first session and the second session The method of changing a communication destination of an IP network system according to any one of claims 5 to 7, further comprising a step of performing charging processing by regarding communication by session as communication by the same session.

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