JP2014017790A - Application server, communication control method, and communication control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly provide a plurality of services in an IP communication network to which a service is provided through a plurality of application servers.SOLUTION: A conference telephone AS 10 (application server) which provides a first additional service through an IP network includes: a signal receiving section 11 for receiving a request signal transmitted to a CW control AS 20 (a second application server) which provides a second additional service which is different from the first additional service, from a user terminal 40; a terminal processing avoidance section 12 which does not perform terminal processing to the request signal when a predetermined parameter is included in the request signal; a signal transmission section 13 for transmitting the request signal to the second application server; and a normal end response section 14 for transmitting to a user terminal a normal end response signal to the request signal after receiving the normal end response signal to the request signal from the second application server.

Description

  The present invention relates to an application server, a communication control method, and a communication control program.

  2. Description of the Related Art Conventionally, as a technology related to an IP communication system that provides a multimedia service, an IMS (IP Multimedia Subsystem: IP multimedia subsystem) that is a communication system platform that provides a multimedia service to a user using SIP (Session Initiated Protocol) )It has been known.

  In IMS, a network composed of SIP servers that perform session control called CSCF (Call Session Control Function) and an application server (AS) network that provides additional services to users and the like are separated. An S-CSCF (Serving CSCF), which is a type of CSCF, performs session control between user terminals, AS service activation control, and the like. Specifically, when the S-CSCF receives a signal requesting an additional service from the user terminal, the S-CSCF performs processing such as user authentication and identification of an AS that provides the additional service, and sends the signal from the user terminal to the corresponding AS. Routing and establishing a session between the user terminal and the AS.

  As described above, the S-CSCF centrally performs session control, AS service activation control, and the like, so that the user can flexibly use additional services provided by a plurality of ASs.

"3GPP TS 24.610 V11.0.0 (2012-03)", 3GPP, issued on March 16, 2012

  However, when a plurality of ASs are used in combination, a request signal transmitted from a user terminal to one AS is transmitted on the basis of a data communication mechanism based on a standard protocol (see Non-Patent Document 1). A situation may occur where an AS is routed. In such a case, if the other AS recognizes the request signal received from the user terminal as a request signal for itself and performs processing (termination processing), the processing by the one AS is not performed, and the entire system As a result, processing may not be performed normally.

  Accordingly, an object of the present invention is to provide a plurality of services smoothly in an IP communication network in which services are provided via a plurality of application servers.

  An application server according to the present invention is an application server that provides a first supplementary service via an IP network, and a second application that provides a second supplementary service different from the first supplementary service from a user terminal. A signal receiving unit that receives a request signal transmitted to the server, and a termination process that prevents a termination process for the request signal from being performed based on the predetermined parameter when the request signal includes a predetermined parameter. After receiving the normal end response signal for the request signal from the avoidance unit, the signal transmission unit for transmitting the request signal to the second application server, and the second application server, the normal end response signal for the request signal is transmitted to the user terminal. A normal end response unit.

  A communication control method according to the present invention is a communication control method executed by an application server that provides a first supplementary service via an IP network. A second control different from the first supplementary service is performed from a user terminal. A signal receiving step for receiving a request signal transmitted to the second application server that provides the supplementary service, and a termination process for the request signal based on the predetermined parameter when the request signal includes the predetermined parameter A termination process avoiding step for preventing the request from being performed, a signal transmitting step for transmitting a request signal to the second application server, and a normal termination for the request signal after receiving a normal termination response signal for the request signal from the second application server A normal termination response step of transmitting a response signal to the user terminal.

  A communication control program according to the present invention is a communication control program for causing a computer to function as an application server that provides a first additional service via an IP network. A signal receiving unit that receives a request signal transmitted to a second application server that provides a different second additional service; and when the request signal includes a predetermined parameter, the request is based on the predetermined parameter. A termination processing avoiding unit for preventing termination of the signal, a signal transmitting unit for transmitting a request signal to the second application server, and a normal termination response signal for the request signal from the second application server, A normal end response unit that transmits a normal end response signal to the signal to the user terminal; and To function Te.

  According to such a form, when the first application server receives the request signal transmitted from the user terminal to the second application server, and the predetermined signal is included in the request signal, the first application server The request signal can be transmitted (transmitted) to the second application server without performing processing based on the request signal as a termination. Thereafter, the first application server receives a normal end response signal for the request signal from the second application server, confirms that the processing for the request signal has been correctly executed, and then sends a normal end response signal to the user terminal. return it. As described above, the first application server transmits a request signal to the second application server, thereby preventing the first application server from interfering with service provision by the second application server. That is, it is possible to implement an application server (first application server) that does not hinder service provision by another application server (second application server).

  The user terminal, the second user terminal, and the third user terminal, which are different terminals, are connected to the IP network, and the second supplementary service is provided between the user terminal and the second user terminal. A call waiting function for switching a first session established between the user terminal and the third user terminal between a call state and a hold state between the user session and the third user terminal. The request signal is a signal for requesting session switching, the predetermined parameter is a parameter indicating a session switching request in the call waiting function, and the application server is configured to execute the first session or the second session. Monitors the status of data communication sent and received through the session, and indicates that there is no communication over a predetermined time A communication monitoring unit that determines that the session is abnormal when detecting the communication, and a communication monitoring stop unit that stops monitoring the data communication by the communication monitoring unit for the session that is put on hold by the call waiting function. May be.

  According to such a form, since the first application server transmits a session switching request signal from the user terminal to the second application server (call waiting control server), the session switching process is executed by the second application server. . Here, data communication is not performed in the session that is put on hold by the session switching process by the second application server. Therefore, when the first application server includes a communication monitoring unit that monitors the state of the data communication, the communication monitoring unit detects a no-communication state for a predetermined time or more and determines that the session is abnormal. Processing may cause unintended processing such as session disconnection. Therefore, by stopping the monitoring of data communication by the communication monitoring unit for the session put on hold by the session switching process by the second application server, the communication monitoring unit is put on hold and becomes a no-communication state. Can be judged as abnormal. As described above, the application server (first application server) that does not hinder the provision of the call waiting function by another application server (second application server) can be implemented.

  According to the present invention, in an IP communication network in which services are provided via a plurality of application servers, it is possible to implement an application server that provides services without interfering with service provision by other application servers. Services can be provided smoothly.

It is a block diagram which shows the whole structure of the data communication system containing the application server which concerns on embodiment. It is a hardware block diagram of the application server which concerns on embodiment. It is a figure which shows the flow of the call session request signal which concerns on a 1st example. It is a figure which shows the flow of the call session request signal which concerns on a 2nd example. It is a figure which shows the communication flow at the time of the switch to the 2nd call which concerns on a 1st example. It is a figure which shows the data communication flow at the time of switching back to the 1st call based on a 1st example. It is a figure which shows the data communication flow at the time of the switch to the 2nd call which concerns on a 2nd example. It is a figure which shows the data communication flow at the time of switching back to the 1st call based on a 2nd example. It is a block diagram which shows the function structure of the communication control program which concerns on embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

  First, an overall system configuration of a data communication system including an application server according to the embodiment will be described with reference to FIG. The data communication system 1 shown in FIG. 1 includes a conference call AS10 (application server, first application server), CW control AS (second application server), guidance AS30, user terminal 40, user terminal 50, and user terminal 60. These devices communicate with each other via an IP network N configured by a group of SIP servers called CSCFs.

  Next, FIG. 2 shows a hardware configuration common to the conference call AS10, the CW control AS, and the guidance AS30. As shown in FIG. 2, the conference call AS10, the CW control AS, and the guidance AS30 each include a CPU 101 that executes an operating system, an application program, and the like, a main storage unit 102 that includes ROM and RAM, a hard disk memory, and the like. An auxiliary storage unit 103 configured, a communication control unit 104 that performs data communication, an output unit 105 configured by a liquid crystal monitor, an operation unit 106 configured by a keyboard and a mouse as input devices, and a USB memory And a recording medium reading unit 107 for reading a recording medium 200 such as a CD-ROM or a DVD.

  Each function of the telephone conference AS10, CW control AS, and guidance AS30 shown in FIG. 1 is realized by reading and executing a predetermined software program in the main storage unit 102 under the control of the CPU 101. At that time, the CPU 101 controls data reading and writing operations in the main storage unit 102 and the auxiliary storage unit 103 according to the processing procedure of the software program, and controls operations of the operation unit 106, the output unit 105, and the communication control unit 104. .

  Next, the outline | summary of each apparatus shown in FIG. 1 is demonstrated.

  The teleconference AS10 is an AS that provides functions (first additional service) such as call communication and call recording by mediating a call session between a plurality of user terminals. The telephone conference AS10 includes a signal receiving unit 11, a termination process avoiding unit 12, a signal transmitting unit 13, a normal end response unit 14, a communication monitoring unit 15, and a communication monitoring stopping unit 16.

  Voice communication between user terminals is performed by transmitting and receiving voice data using RTP / RTCP (Real-Time Transport Protocol / RTP Control Protocol) in a session established between user terminals. The teleconference AS10 mediates this session (establishes an RTP / RTCP session between each user terminal and the teleconference AS10), thereby enabling the voice call between the user terminals and the first additional service. provide.

  The signal receiving unit 11 is a functional element that receives a data signal transmitted from a user terminal or another AS via the IP network N.

  The termination processing avoiding unit 12 identifies whether the data signal received by the signal receiving unit 11 includes a session switching request parameter indicating that it is a session switching request in the call waiting function, and switches the session to the data signal. This is a functional element that selects not to perform termination processing on the data signal when a request parameter is included.

  The signal transmission unit 13 is a functional element that transmits a data signal including a session switching request parameter to the CW control AS 20 that provides a later-described call waiting function via the IP network N.

  The normal end response unit 14 is a functional element that receives a normal end response signal for a data signal including a session switching request parameter from the CW control AS 20, and then transmits a normal end response signal for the data signal to the user terminal.

  The communication monitoring unit 15 is a functional element that monitors a data communication state transmitted / received through a session established on the conference call AS20 and determines that a session abnormality has occurred when a no-communication state for a predetermined time or longer is detected.

  The communication monitoring stop unit 16 is a functional element that stops monitoring of data communication by the communication monitoring unit 15 for a session that is put on hold by a session switching process by the call waiting function of the CW control AS 20.

  The CW control AS 20 is an AS that provides a call waiting function (second supplementary service). The call waiting function can be used from the user terminal by mediating a call session between the user terminal using the function and another user terminal. Specifically, when the CW control AS 20 receives a session switching request signal (hereinafter referred to as “reINVITE”) from the user terminal, the CW control AS 20 activates the call waiting function and responds to the first call. A session switching process for switching between a session (first session) and a session corresponding to the second call (second session) between a call state and a hold state is executed.

  Guidance AS30 is AS which transmits the guidance audio | voice signal which shows a holding state with respect to the user terminal of the holding | maintenance destination of the telephone call session put on hold by the call waiting function of CW control AS20. The guidance voice signal is transmitted according to the following procedure. First, the CW control AS 20 transmits reINVITE including connection destination information of the guidance AS 30 to the adjacent user terminal or the telephone conference AS 10 in the route of the session to be switched to the hold state. Thereafter, the user terminal or telephone conference AS10 that has received reINVITE establishes a session with the guidance AS30. Through the session, a guidance voice signal is transmitted from the guidance AS 30 to the user terminal.

  The user terminal 40 (first user terminal), the user terminal 50 (second user terminal), and the user terminal 60 (third user terminal) are connected via the IP network N and can communicate with each other. It is a user terminal. These user terminals make a call using the conference call AS10. Furthermore, the user terminal 40 can use the call waiting function by the CW control AS 20. When the user terminal 40 has already established a call session (first session) with the user terminal 50, a call session request signal (hereinafter, the call session request signal is expressed as “INVITE”) from the user terminal 60. When a call is made, a predetermined call sound flows in the user terminal 40, so that the user of the user terminal 40 knows that a new call session (second session) has been requested. Here, the user requests the CW control AS 20 to put the first session on hold from the user terminal 40 by performing a predetermined operation (such as pushing a specific button) on the user terminal 40. reINVITE is transmitted. Thereafter, the session switching process is executed by the call waiting function of the CW control AS 20.

  Next, the flow of INVITE in call communication using the conference call AS10 and the CW control AS20 will be described with reference to FIGS. Note that data communication between the user terminal and each AS is actually performed by being routed by the CSCF via the IP network N, but the IP network N is omitted in these drawings.

(INVITE flow in the first example)
First, referring to FIG. 3, when the first session is established between the user terminal 40 and the user terminal 50 because the user terminal 40 transmits INVITE to the user terminal 50, the user terminal 60 sends the user to the user terminal 50. The flow of INVITE when INVITE for terminal 40 is transmitted will be described.

  Since the CW control AS 20 needs to perform session switching control, it is transmitted toward the user terminal 40 from INVITE transmitted from the user terminal 40 or from a terminal other than the user terminal 40 (the user terminal 50 or the user terminal 60). The INVITE is first transmitted to the CW control AS 20. Next, in order to establish a session between user terminals via the conference call AS10, the CW control AS 20 that has received INVITE transmits INVITE to the conference call AS10.

  As described above, the INVITE from the user terminal 40 to the user terminal 50 is transmitted in the order of the user terminal 40, the CW control AS 20, the telephone conference AS 10, and the user terminal 50 as shown by the solid line in FIG. On the other hand, INVITE from the user terminal 60 to the user terminal 40 is transmitted in the order of the CW control AS 20, the telephone conference AS 10, and the user terminal 40 as indicated by the dotted line in FIG. 3.

  The call session (first session) between the user terminal 40 and the user terminal 50 and the call session (second session) between the user terminal 40 and the user terminal 60 are performed by the CW control AS 20 that has received reINVITE from the user terminal 40. By performing the session switching process by function, the call state and the hold state can be switched to each other. Here, the reINVITE transmitted from the user terminal 40 to the CW control AS 20 is a route (hereinafter referred to as a “session route”) in which INVITE flows because the route of the session to be switched is established due to technical specifications such as a communication protocol. Is transmitted to an adjacent node (user terminal or AS).

  Therefore, the reINVITE for the first session transmitted from the user terminal 40 is transmitted to the adjacent CW control AS 20 in the session path indicated by the solid line in FIG. On the other hand, the reINVITE for the second session transmitted from the user terminal 40 is transmitted to the adjacent conference call AS10 in the session path indicated by the dotted line in FIG.

  The flow of the guidance voice signal transmitted to the user terminal in the on-hold state is shown by a one-dot chain line in FIG. When the CW control AS 20 receives reINVITE requesting to switch the session to the hold state, the CW control AS 20 transmits reINVITE holding the connection destination information of the guidance AS 30 to the user terminal in the hold state or the guidance AS 10. The user terminal or the guidance AS 10 that has received the reINVITE refers to the connection destination information of the guidance AS 30 included in the reINVITE, and establishes a session with the guidance AS 30. Thereby, the guidance audio | voice signal from guidance AS30 is transmitted to the said user terminal via the said session.

  Here, the reINVITE transmitted by the CW control AS 20 is transmitted to adjacent nodes in the session path as described above. Therefore, when switching the state of the first session, reINVITE from the CW control AS 20 is transmitted to the adjacent conference call AS 10 in the session path, and the conference call AS 10 establishes a session with the guidance AS 30. Therefore, the guidance voice signal from the guidance AS 30 is transmitted to the user terminal 50 via the conference call AS20. On the other hand, when switching the state of the second session, reINVITE from the CW control AS 20 is transmitted to the adjacent user terminal 60 in the session path, and the user terminal 60 establishes a session with the guidance AS 30. Therefore, the guidance voice signal from the guidance AS 30 is directly transmitted to the user terminal 60.

(INVITE flow in the second example)
Next, when the first session is established between the user terminal 40 and the user terminal 50 as a result of the user terminal 50 transmitting INVITE to the user terminal 40 with reference to FIG. The flow of INVITE when INVITE for the user terminal 40 is transmitted will be described. Note that the description of the same content as that described in the first example is omitted.

  As indicated by a solid line in FIG. 4, INVITE from the user terminal 50 to the user terminal 40 is transmitted in the order of the user terminal 50, the CW control AS 20, the conference call AS 10, and the user terminal 40. On the other hand, INVITE from the user terminal 60 to the user terminal 40 is also transmitted in the order of the user terminal 60, the CW control AS 20, the telephone conference AS 10, and the user terminal 40, as indicated by the dotted line in FIG.

  The reINVITE transmitted by the CW control AS 20 for switching the session state is transmitted to the adjacent user terminal 50 in the session path when the state of the first session is switched. Further, when switching the state of the second session, it is transmitted to the adjacent user terminal 60 in the session path. As described above, in any case, a direct session is established between the guidance AS 30 and the user terminal 50 or the user terminal 60, and the guidance voice signal is transmitted from the guidance AS 30 to the user as shown by a one-dot chain line in FIG. Directly transmitted to the terminal 50 or the user terminal 60.

  Next, regarding the first example and the second example, the data signal flow in the case where the second session is established with the first session held and when the second session is switched back to the first session The function and effect of each functional element of the teleconference AS10 will be described while specifically explaining. As a usage form of the call waiting function, a terminal other than the user terminal 40 (user terminal 50 or user terminal 60) may switch the session by using the call waiting function. In this case, the user terminal The terminal other than 40 may be a call waiting function different from the call waiting function provided for the user terminal 40 by the CW control AS 20 (a service activated on the same AS or may be activated on a different AS. This is not considered because it is beyond the scope of this embodiment.

  Hereinafter, the data communication flows of the first example and the second example will be specifically described with reference to FIGS. In these figures, the data communication flow and voice data communication (RTP / RTCP communication) related to the first session are shown by solid lines, and the data communication flow and voice data communication (RTP / RTCP communication) related to the second session are shown by dashed lines. Represent.

(Data communication flow of the first example)
First, using FIG. 5, the user terminal 40 transmits INVITE to the user terminal 50 to establish a call session (first session) with the user terminal 50, and then the user terminal 60 transmits INVITE to the user terminal 40. A data communication flow until the user terminal 40 establishes a call session (second session) with the user terminal 60 by placing the first session on hold will be described.

  The INVITE for the user terminal 50 transmitted from the user terminal 40 is transmitted in the order of the CW control AS 20, the telephone conference AS10, and the user terminal 50 (steps S101 to S103). Thereafter, the user terminal 50, the conference call AS10, and the CW control AS20 sequentially return a normal end response (200 OK) to the INVITE (steps S104 to S106). As a result, a call session (first session) corresponding to the first call is established between the user terminal 40 and the user terminal 50 via the conference call AS10 (step S107). The user terminal 40 and the user terminal 50 make a voice call through the first session.

  When INVITE is transmitted from the user terminal 60 to the user terminal 40, the INVITE is transmitted from the user terminal 60 in the order of the CW control AS 20, the conference call AS10, and the user terminal 40 (steps S108 to S110). As a result, the user terminal 40 sounds a predetermined call sound informing that the second call is requested, and the user of the user terminal 40 knows that the second call is requested.

  The user of the user terminal 40 transmits a reINVITE requesting the CW control AS 20 to switch the first session to the hold state by performing a predetermined operation (such as pushing a specific button) on the user terminal 40. (Step S111).

  The CW control AS 20 receives reINVITE from the user terminal 40 and performs processing for placing the first session on hold. Specifically, the CW control AS 20 transmits reINVITE holding the connection destination information of the guidance AS 30 to the adjacent conference call AS 10 in the session path (step S112). The telephone conference AS10 extracts the connection destination information of the guidance AS30 from the reINVITE, establishes a session with the guidance AS30, and returns a normal end response to the CW control AS20 (step S113). Accordingly, the first session is put on hold, and the guidance voice from the guidance AS 30 is transmitted to the user terminal 50 via the conference call AS10 (step S114). The CW control AS 20 determines that the process for placing the first session on hold is completed when the normal termination response is received from the conference call AS 10 in step S113, and the normal termination response to the reINVITE received from the user terminal 40 in step S111. Is returned (step S115).

  Thereafter, the user terminal 40, the telephone conference AS10, and the CW control AS20 respectively return normal end responses to the INVITE received in step S110, step S109, and step S108 in order (step S116, step S117, and step S118). Thereby, the 2nd session which mediates telephone conference AS10 is established between the user terminal 40 and the user terminal 60 (step S119). The user terminal 40 and the user terminal 60 make a voice call through the second session.

  As described above, the data signal and the processing flow when the user terminal 40 switches the call state from the first session established by sending the INVITE to the second session have been described with reference to FIG. In this case, the reINVITE transmitted from the user terminal 40 to the CW control AS 20 in order to place the first session on hold is based on the session path of the first session, and the adjacent CW control in the session path from the user terminal 40. It is sent directly to the AS 20 and does not go through the conference call AS 10. Accordingly, in this case, the problem described later does not occur, and the session switching process by the call waiting function is smoothly executed as described above.

  Next, the data communication flow until the second session is put on hold and the first session is put into a call state again will be described using FIG.

  The user terminal 40 transmits reINVITE including a session switching request parameter for switching the second session to the hold state. Here, as shown in FIGS. 3 and 5, the second session is established by transmitting INVITE from the user terminal 60 in the order of the CW control AS 20, the telephone conference AS 10, and the user terminal 40. Therefore, the reINVITE is transmitted from the user terminal 40 to the adjacent conference call AS10 in the session path (step 120, signal reception step).

  When the signal reception unit 11 receives the reINVITE, the telephone conference AS 10 determines that the reINVITE includes a session switching request parameter by the termination process avoiding unit 12, and does not perform the termination process. Thereafter, the reINVITE is transmitted to the CW control AS 20 by the signal transmission unit 13 (step S121, termination process avoidance step, signal transmission step). As described above, the CW control AS 20 can receive the reINVITE by transmitting (transmitting) the teleconference AS 10 to the CW control AS 20 without performing the termination process for the reINVITE including the session switching request parameter.

  In addition to the reINVITE, the user terminal 40 transmits a reINVITE requesting that the first session is returned to the call state to the CW control AS 20 (step S122). Since the reINVITE is for the first session, the reINVITE is directly transmitted from the user terminal 40 to the adjacent CW control AS 20 in the session path based on the path of the first session.

  The CW control AS 20 performs a process for placing the second session on hold based on the reINVITE received from the conference call AS 10 in step S121. Specifically, reINVITE holding the connection destination information of the guidance AS 30 is transmitted to the user terminal 60 (step S123). Thereafter, the user terminal 60 establishes a session with the guidance AS 30, and then returns a normal end response to the CW control AS 20 (step S124). With the establishment of the session, a guidance voice signal is transmitted from the guidance AS 30 to the user terminal 60 (step 125).

  As a result of the above processing, the user terminal 60 switches from the conference call AS10 to the connection with the guidance AS30 (becomes on hold), and on the session between the user terminal 60 and the conference call AS10 (second session for the conference call AS10). Voice data communication (RTP / RTCP communication) is eliminated. That is, the second session is in a no-communication state. If this state continues for a predetermined time or longer, the communication monitoring unit 15 determines that the state of the second session is abnormal. In the worst case, the function of the conference call AS 10 (not shown) causes the second session to be determined. Will be cut off. Accordingly, the telephone conference AS10 stops the data communication monitoring by the communication monitoring unit 15 for the second session put on hold by the communication monitoring stop unit 16 (step 126). As a result, it is possible to prevent the communication monitoring unit 15 from continuing to monitor communication of a session that has been put on hold and in a no-communication state to determine that the session is abnormal.

  The CW control AS 20 determines that the process of placing the second session on hold is completed when the normal end response is received from the user terminal 60 in step S124, and the normal end response to the reINVITE received from the conference call AS 10 in step S121. Is returned (step S127). Thereafter, the conference call AS 10 confirms that the normal end response unit 114 has received the normal end response signal for reINVITE including the session switching request parameter from the CW control AS 20, and then transmits the normal end response signal to the user terminal 40. (Step 128, normal end response step). Thereby, the user terminal 40 is correctly notified that the process for reINVITE including the session switching request parameter transmitted from the user terminal 40 to the CW control AS 20 via the conference call AS 10 has been processed normally by the CW control AS 20. be able to.

  On the other hand, based on the reINVITE received in step S122, the CW control AS 20 transmits reINVITE holding the connection destination information of the user terminal 50 to the conference call AS10 (step S129). The telephone conference AS10 receives the reINVITE, extracts the connection destination information of the user terminal 50 from the reINVITE, recovers the session with the user terminal 50, and returns the first session to the call state again. Then, a normal end response is returned to the CW control AS 20 (step S130). Subsequently, the CW control AS 20 performs the switchback process of the first session upon receiving the normal end response, so that the connection information of the conference call AS 10 is added to the normal end response to the reINVITE received from the user terminal 40 in Step 122. It is returned including (step S131). As a result, the user terminal 40 and the user terminal 50 make a call again via the first session (step S132).

(Data communication flow in the second example)
First, using FIG. 7, the user terminal 40 receives INVITE from the user terminal 50 and establishes a call session (first session) with the user terminal 50, and then the user terminal 60 transmits INVITE to the user terminal 40. A data communication flow until the user terminal 40 establishes a call session (second session) with the user terminal 60 by placing the first session on hold will be described.

  The INVITE for the user terminal 40 transmitted from the user terminal 50 is transmitted in the order of the CW control AS 20, the telephone conference AS 10, and the user terminal 40 (steps S201 to S203). Thereafter, the user terminal 40, the telephone conference AS10, and the CW control AS20 sequentially return a normal end response to the INVITE (Steps S204 to S206). As a result, a call session (first session) for the first call is established between the user terminal 40 and the user terminal 50 via the conference call AS10 (step S207). The user terminal 40 and the user terminal 50 make a voice call through the first session.

  When INVITE is transmitted from the user terminal 60 to the user terminal 40, the INVITE is transmitted from the user terminal 60 to the CW control AS 20, the conference call AS 10, and the user terminal 40 in this order (steps S208 to S210). As a result, the user terminal 40 sounds a predetermined call sound informing that the second call is requested, and the user of the user terminal 40 knows that the second call is requested.

  The user terminal 40 transmits reINVITE including a session switching request parameter for switching the first session to the hold state. Here, as shown in FIG. 4 and steps S201 to 206, the first session is established by transmitting INVITE from the user terminal 50 in the order of the CW control AS 20, the conference call AS10, and the user terminal 40. Therefore, the reINVITE is transmitted from the user terminal 40 to the adjacent conference call AS10 in the session path (step 211, signal reception step).

  When the signal reception unit 11 receives the reINVITE, the telephone conference AS 10 determines that the reINVITE includes a session switching request parameter by the termination process avoiding unit 12, and does not perform the termination process. Thereafter, the reINVITE is transmitted to the CW control AS 20 by the signal transmission unit 13 (step S212, termination process avoidance step, signal transmission step). As described above, the CW control AS 20 can receive the reINVITE by transmitting (transmitting) the teleconference AS 10 to the CW control AS 20 without performing the termination process for the reINVITE including the session switching request parameter.

  The CW control AS 20 performs processing for placing the first session on hold based on the reINVITE received from the conference call AS 10 in step S212. Specifically, reINVITE holding the connection destination information of the guidance AS 30 is transmitted to the user terminal 50 (step S213). The user terminal 50 extracts the connection destination information of the guidance AS 30 from the reINVITE, establishes a session with the guidance AS 30, and returns a normal end response to the CW control AS 20 (step S214). Thereby, the first session is put on hold, and the guidance voice signal from the guidance AS 30 is transmitted to the user terminal 50 (step S215).

  The CW control AS 20 determines that the process of placing the first session on hold is completed when the normal termination response is received from the user terminal 50 in step S214, and the normal termination response to the reINVITE received from the conference call AS10 in step S212. Is returned (step S216). The telephone conference AS10 receives the normal end response and returns a normal end response to the reINVITE received from the user terminal 40 in step 211 (step S217, normal end response step). Thereby, it is possible to correctly notify the user terminal 40 that the process for reINVITE including the parameter transmitted from the user terminal 40 to the CW control AS 20 via the conference call AS 10 has been processed normally by the CW control AS 20. .

  Through the above processing, the user terminal 50 is switched from the conference call AS10 to the connection with the guidance AS30 (becomes suspended), and on the session between the user terminal 50 and the conference call AS10 (first session for the conference call AS10). Voice data communication (RTP / RTCP communication) is eliminated. That is, the first session is in a no-communication state. In order to prevent the communication monitoring unit 15 from determining that the state of the first session is abnormal, the teleconference AS10 is configured to perform a communication monitoring unit for the first session put on hold by the communication monitoring stop unit 16. 15 stops data communication monitoring (step 218). Thereby, it is possible to prevent the communication monitoring unit 15 from continuing communication monitoring of a session that has been put on hold and in a no-communication state to determine that the session is abnormal.

  Thereafter, the user terminal 40, the conference call AS10, and the CW control AS20 respectively return a normal end response to the INVITE received in step S210, step S209, and step S208, respectively (step S219, step S220, and step S221). Thereby, the 2nd session which mediates telephone conference AS10 is established between the user terminal 40 and the user terminal 60 (step S222). The user terminal 40 and the user terminal 60 make a voice call through the second session.

  Next, a data communication flow until the second session is put on hold and the first session is put into a call state again will be described with reference to FIG.

  The user terminal 40 transmits reINVITE including a session switching request parameter for switching the second session to the hold state. Here, as shown in FIGS. 4 and 7, the second session is established by transmitting INVITE from the user terminal 60 in the order of the CW control AS 20, the telephone conference AS 10, and the user terminal 40. Accordingly, the reINVITE is transmitted from the user terminal 40 to the adjacent conference call AS10 in the session path (step 223, signal reception step).

  When the signal reception unit 11 receives the reINVITE, the telephone conference AS 10 identifies that the reINVITE includes a session switching request parameter by the termination process avoiding unit 12, and does not perform the termination process. Thereafter, the signal transmission unit 13 transmits the reINVITE to the CW control AS 20 (step S224, termination process avoidance step, signal transmission step). As described above, the CW control AS 20 can receive the reINVITE by transmitting (transmitting) the teleconference AS 10 to the CW control AS 20 without performing the termination process for the reINVITE including the session switching request parameter.

  In addition to the reINVITE, the user terminal 40 transmits reINVITE including a session switching request parameter for requesting that the first session be returned to the call state. Since the reINVITE is for the first session, it is transmitted from the user terminal 40 to the adjacent conference call AS10 in the session path of the first session (step S225, signal reception step). Here, the telephone conference AS10 transmits the reINVITE to the CW control AS20 by performing the same processing as in steps S223 and S224 (step 226, termination processing avoidance step, signal transmission step).

  The CW control AS 20 performs a process for placing the second session on hold based on the reINVITE received from the conference call AS 10 in step S224. Specifically, reINVITE holding the connection destination information of the guidance AS 30 is transmitted to the user terminal 60 (step S227). Thereafter, the user terminal 60 establishes a session with the guidance AS 30, and then returns a normal end response to the CW control AS 20 (step S228). As the session is established, a guidance voice signal is transmitted from the guidance AS 30 to the user terminal 60 (step 229).

  With the above processing, the user 60 switches from the conference call AS10 to the connection with the guidance AS30 (becomes a suspended state), and on the session between the user terminal 60 and the conference call AS10 (first session for the conference call AS10), There is no voice data communication (RTP / RTCP communication). That is, the second session is in a no-communication state. In order to prevent the communication monitoring unit 15 from determining that the state of the second session is abnormal, the teleconference AS10 is configured to perform a communication monitoring unit for the second session put on hold by the communication monitoring stop unit 16. 15 stops data communication monitoring (step 230). Thereby, it is possible to prevent the communication monitoring unit 15 from continuing communication monitoring of a session that has been put on hold and in a no-communication state to determine that the session is abnormal.

  The CW control AS 20 determines that the process of placing the second session on hold is completed when the normal termination response is received from the user terminal 60 in step S228, and the normal termination response to the reINVITE received from the conference call AS10 in step S224. Is returned to the telephone conference AAS10 (step S231). Thereafter, the conference call AS 10 confirms that the normal end response unit 114 has received the normal end response signal for reINVITE including the session switching request parameter from the CW control AS 20, and then transmits the normal end response signal to the user terminal 40. (Step 232, normal end response step). Thereby, the user terminal 40 is correctly notified that the process for reINVITE including the session switching request parameter transmitted from the user terminal 40 to the CW control AS 20 via the conference call AS 10 has been processed normally by the CW control AS 20. be able to.

  On the other hand, the CW control AS 20 holds the connection destination information of the conference call AS10 for the user terminal 50 based on the reINVITE requesting to switch the first session received from the conference call AS10 back to the call state in step S226. The reINVITE thus transmitted is transmitted (step S233). The user terminal 50 receives the reINVITE, extracts connection destination information of the conference call AS10 from the reINVITE, recovers the session with the conference call AS10, and returns a normal end response to the CW control AS20 ( Step S234). Subsequently, the CW control AS 20 performs the switchback process of the first session upon receiving the normal end response, so that the connection information of the conference call AS10 is added to the normal end response to the reINVITE received from the conference call AS10 in step S226. The information is returned to the conference call AS10 (step S235). Further, the conference call AS10 receives the normal end response from the CW control AS 20, and returns the normal end response to the user terminal 40 as a normal end response to the reINVITE received from the user terminal 40 in step S225 (step S236). As a result, the user terminal 40 and the user terminal 50 make a call again via the first session (step S237).

(About communication control program)
Next, a communication control program P10 for causing a computer to function as a telephone conference AS10 (application server, first application server) will be described with reference to FIG.

  FIG. 9 is a block diagram showing modules of the communication control program P10 that can execute the communication control method. As shown in FIG. 9, the communication control program P10 includes a signal reception module P11, a termination processing avoidance module P12, a signal transmission module P13, and a normal termination response module P14. The functions realized by executing each of the modules are the same as the functions of the corresponding components in the above-described conference call AS10. That is, the functions of the signal reception module P11, the termination processing avoidance module P12, the signal transmission module P13, and the normal termination response module P14 are the signal reception unit 11, the termination processing avoidance unit 12, the signal transmission unit 13, and the normal termination response unit, respectively. This is the same as the 14 function.

  The communication control program P10 configured in this way is stored in the recording medium 120 shown in FIG. 2, and is executed by a computer used as the telephone conference AS10. When the recording medium 200 is inserted into the recording medium reading unit 107, the computer can access the communication control program P10 stored in the recording medium 200 from the recording medium reading unit 107, and execute the communication control program P10. By this, it becomes possible to operate as the conference call AS 10 (application server, first application server) according to the present embodiment.

  The communication control program P10 may be provided via a network as a computer data signal superimposed on a carrier wave. In this case, the computer used as the conference call AS 10 can execute the communication control program P 10 by storing the communication control program P 10 received by the communication control unit 104 in the main storage unit 102.

  As described above, according to the present embodiment, the conference call AS 10 (application server, first application server) does not perform termination processing for the session switching request including the session switching request parameter, and the CW control AS 20 (second By transmitting (transparent) the session switching request to the application server, the CW control AS 20 can receive the session switching request and execute the session switching process. The conference call AS 10 receives a normal end response signal for the session switch request from the CW control AS 20 and then transmits a normal end response signal for the session switch request to the user terminal, whereby the session switch by the CW control AS 20 is performed. It is possible to correctly notify the user terminal that the process has been completed normally. Furthermore, the conference call AS10 continues to monitor the communication of the session that has been put on hold and not in communication by stopping monitoring the data communication of the session put on hold by the session switching process of the CW control AS20. It can be prevented that the session is abnormal.

  That is, according to the present embodiment, in an IP communication network in which services are provided via a plurality of application servers, an application server that provides services without interfering with service provision by other application servers can be implemented. It is possible to provide a plurality of services smoothly.

  In the embodiment according to the present invention, the case where the application server (first application server) is the conference telephone AS10 and the second application server is the CW control AS20 has been described in detail. However, the use of the first application server and the second application server is not limited to this. That is, according to the technical specifications such as the communication protocol, the present invention is such that the request signal transmitted from the user terminal 40 to the second application server passes through the first application server. And the second application server.

  As mentioned above, this invention is not limited to the said embodiment, A various deformation | transformation is possible in the range which does not deviate from the summary.

  DESCRIPTION OF SYMBOLS 10 ... Conference call AS (application server, 1st application server), 11 ... Signal receiving part, 12 ... Termination process avoidance part, 13 ... Signal transmission part, 14 ... Normal completion response part, 15 ... Communication monitoring part, 16 ... Communication Monitoring stop unit, P10 ... communication control program, P11 ... signal reception module, P12 ... termination processing avoidance module, P13 ... signal transmission module, P14 ... normal termination response module.

Claims (4)

An application server that provides a first supplementary service via an IP network,
A signal receiving unit that receives a request signal transmitted from a user terminal to a second application server that provides a second additional service different from the first additional service;
A termination processing avoiding unit that prevents termination processing for the request signal based on the predetermined parameter when the request signal includes a predetermined parameter;
A signal transmission unit for transmitting the request signal to the second application server;
A normal end response unit that transmits a normal end response signal for the request signal to the user terminal after receiving a normal end response signal for the request signal from the second application server;
An application server comprising The user terminal, the second user terminal, and the third user terminal, which are different terminals, are connected to the IP network,
The second supplementary service calls between a first session established between the user terminal and the second user terminal and a second session established between the user terminal and a third user terminal. Is a service that provides a call waiting function that switches between a state and a hold state,
The request signal is a signal for requesting session switching,
The predetermined parameter is a parameter indicating a session switching request in the call waiting function,
The application server monitors a data communication state transmitted / received through the first session or the second session, and detects a no-communication state for a predetermined time or more, and determines a session abnormality,
A communication monitoring stop unit for stopping monitoring of data communication by the communication monitoring unit for a session put on hold by the call waiting function;
The application server according to claim 1, further comprising: A communication control method executed by an application server that provides a first additional service via an IP network,
A signal receiving step of receiving a request signal transmitted from a user terminal to a second application server that provides a second additional service different from the first additional service;
A termination process avoiding step for preventing termination of the request signal based on the predetermined parameter when the request signal includes a predetermined parameter;
A signal transmission step of transmitting the request signal to the second application server;
A normal end response step of transmitting a normal end response signal for the request signal to the user terminal after receiving a normal end response signal for the request signal from the second application server;
Including a communication control method. A communication control program for causing an application server to function as a first additional service via an IP network,
Computer
A signal receiving unit that receives a request signal transmitted from a user terminal to a second application server that provides a second additional service different from the first additional service;
A termination processing avoiding unit that prevents termination processing for the request signal based on the predetermined parameter when the request signal includes a predetermined parameter;
A signal transmission unit for transmitting the request signal to the second application server;
A normal end response unit that receives a normal end response signal for the request signal from the second application server and then transmits a normal end response signal for the request signal to the user terminal;
Communication control program to function as

Images