JP2009232318A - Communication relay method, communicating relay program, and communication relay apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To call a subscriber who has registered a new PBX instead of a disabled PBX. <P>SOLUTION: A plurality of exchange servers are grouped to configure a local distribution set. Not an SIP domain name of the exchange server but an SIP domain name of the local distribution set is attached to an SIP address of a telephone terminal registered to the exchange server which configures the local distribution set, to notify the other subscriber thereof. When each exchange server receives a message transmitted to the SIP address having the SIP domain name of the local distribution set to which the exchange server belongs as a configuration member, the exchange server replaces the SIP domain name of the destination SIP address with the SIP domain name of each exchange server configuring the local distribution set, and transmits the message. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication relay method in IP telephone communication, and more particularly, to a communication relay method that facilitates transmission from a non-operating IP-PBX to a subscriber whose registration is changed to another IP-PBX.

IP telephone communication based on VoIP (Voice over Internet Protocol), which is a telephone communication technology compliant with the Internet Protocol (IP), is becoming widespread, and instead of the conventional PBX (private branch exchange), IP-PBX (hereinafter referred to as an exchange server) Is called). Unlike the conventional PBX, the exchange server can accommodate remote telephone terminals. For this reason, the area where one exchange server provides telephone service is wider than the conventional PBX (see, for example, Patent Document 1).
JP 2006-157776 A

  As a result, when a disaster such as an earthquake occurs, the equipment in the area where the subscriber a is located is not damaged, but the exchange server is damaged and cannot operate and cannot receive telephone service. . In this case, subscriber a can register with another exchange server and receive telephone service, but subscriber a who wants to send to subscriber a has registered with other exchange server. I don't know. Therefore, there is a problem that the subscriber b cannot make a call to the subscriber a unless there is a change notification from the subscriber a.

  An object of the present invention is to provide a communication relay method that facilitates transmission from a non-operating exchange server to a subscriber whose registration is changed to another exchange server.

  A communication relay method according to the present invention is a communication relay method executed by an exchange server that is a member of an exchange server group having a plurality of exchange servers as members, and includes a plurality of exchange servers in the domain name of the exchange server group. When storing the domain name in association with each other, receiving the first call connection request for the communication device, and when the domain name included in the destination address of the first call connection request is the domain name of the exchange server group And generating a second call connection request by replacing the domain name included in the destination address of the first call connection request with the domain name of the exchange server stored in association with the domain name of the exchange server group; And a step of transmitting a second call connection request to the communication device, That.

  A communication relay program according to the present invention is a communication relay program that causes a computer that is a member of an exchange server group having a plurality of exchange servers as members to execute a communication relay method, and the communication relay method includes an exchange server group Storing the domain name of a plurality of exchange servers in association with the domain name of the first, a step of receiving a first call connection request for the communication device, and a domain name included in a destination address of the first call connection request When it is the domain name of the exchange server group, the domain name included in the destination address of the first call connection request is replaced with the domain name of the exchange server stored in association with the domain name of the exchange server group. Generating a second call connection request and a second call connection request. Characterized in that it comprises the steps of transmitting to the device.

  The communication relay device according to the present invention is a communication relay device that is a member of an exchange server group having a plurality of exchange servers as members. The domain names of the exchange servers are associated with the domain names of the exchange server group. When the domain name included in the destination address of the received first call connection request is the domain name of the exchange server group, An exchange server group for generating a second call connection request by replacing the domain name included in the destination address of one call connection request with the domain name of the exchange server stored in association with the domain name of the exchange server group And a management unit.

    According to the present invention, a plurality of exchange servers are grouped, a connection request is sent to the group, and a connection request is sent to a telephone terminal that belongs to any exchange server in the group. It is possible to provide a communication relay method that facilitates transmission to a subscriber whose registration is changed in the exchange server.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
In the description of this embodiment, it is assumed that SIP (Session Initiation Protocol) is adopted as a call control protocol.

  FIG. 1 is a diagram for explaining an example of an IP telephone service by an exchange server. An example of an IP telephone service by an exchange server will be described with reference to FIG. The subscriber applies in advance to the telephone service provider and has a subscriber ID assigned. The telephone service provider creates subscriber data and notifies each exchange server. FIG. 2 is a diagram illustrating an example of subscriber data. An example of the subscriber data shown in FIG. 2 will be described. Subscriber data consists of variable data and fixed data. The variable data is data described when the subscriber registers the telephone terminal with one of the exchange servers. Fixed data is data that is written when a subscriber subscribes to a telephone service. Therefore, at the time of subscription to the telephone service, only fixed data is described as shown in FIG. The content of the fixed data may be changed by the telephone service provider according to the request from the subscriber. In that case, the changed contents are notified to each exchange server. An example of variable data will be described later. Fixed data includes subscriber ID, password, and data related to provision of various services. The subscriber ID is assigned by the telephone service provider. The password is selected by the subscriber. As an example of data relating to the provision of various services, FIG. 2 shows an example of data relating to an answering service and a transfer destination when there is no response. Note that variable data and fixed data may be managed separately.

  The subscriber can receive by registering with any exchange server. In the example of FIG. 1, a “register” request is transmitted from the telephone terminal of the subscriber 2000 (referred to as a subscriber assigned with “2000” as the subscriber ID) to the exchange server A (step S12). Thus, the telephone terminal of the subscriber 2000 is registered in the exchange server A. FIG. 3 is a diagram illustrating an example of subscriber data managed by the exchange server A. Exchange server A registers variable data in the subscriber data of subscriber 2000. The variable data includes registration IP address, terminal capability, and registration date / time data. The registered IP address is the IP address of the telephone terminal of the subscriber 2000. The terminal capability is data collected by the exchange server A from the telephone terminal of the subscriber 2000. The registration date / time is data of the date / time when the exchange server A processes the “register” request. As a result of registration with the exchange server A, the SIP address of the telephone terminal of the subscriber 2000 is 2000 @ A. Here, A is a SIP domain name that serves as an identifier for identifying the exchange server A. For simplicity of explanation, the exchange server name is assumed to be the SIP domain name. The variable data in the subscriber data is deleted when a certain valid period elapses after registration. Therefore, in order to keep the registration state at all times, it is necessary to perform the registration procedure again before the validity period elapses.

  In FIG. 1, subscriber 2001 calls subscriber 2000. The telephone terminal of the subscriber 2001 transmits an “invite” request (call connection request) with 2000 @ A as the destination SIP address to an arbitrary exchange server (exchange server B in FIG. 1) (step S14). Receiving this, exchange server B transfers an “invite” request to exchange server A according to the SIP domain name of the destination SIP address (step S16). In response to this, the exchange server A transfers an “invite” request to the telephone terminal of the subscriber 2000 according to the subscriber data managed by itself (step S18). As a result, an “invite” request from the telephone terminal of the subscriber 2001 reaches the telephone terminal of the subscriber 2000.

  FIG. 4 is a diagram for explaining the operation when the exchange server is not in operation. The operation when the exchange server is not operating will be described with reference to FIG. Assume that the telephone terminal of the subscriber 2000 is registered in the exchange server A. When the exchange server A becomes inoperable for some reason such as an earthquake, the exchange server A does not accept any message from another communication device. For example, even when the subscriber 2001 calls the subscriber 2000 (step S22), the response from the exchange server A is not returned to the “invite” request (step S24) transferred to the exchange server A by the exchange server B. . Further, even if the telephone terminal of the subscriber 2000 transmits a “register” request again to the exchange server A before the valid period of registration elapses (step S26), no response from the exchange server A is obtained.

  In response to the failure of the registration procedure for the exchange server A, the subscriber 2000 performs the registration procedure for another exchange server (the exchange server C in FIG. 4) (step S28). As a result, the SIP address of the telephone terminal of the subscriber 2000 becomes 2000 @ C. This exchange server registration change may be set in the telephone terminal of the subscriber 2000 so that it is automatically performed in the event of an emergency. This exchange server registration change allows subscriber 2000 to continue to receive calls, but in order to receive calls addressed to subscriber 2000, inform the other party that the SIP address has changed to 2000 @ C. It is necessary to keep.

  When the subscriber 2001 sends an “invite” request with 2000 @ C as the destination SIP address to an arbitrary exchange server (exchange server B in FIG. 4) (step S30), the exchange server B that has received the request sends the destination SIP address. The “invite” request is transferred to the exchange server C according to the SIP domain name (step S32). In response to this, the exchange server C transfers an “invite” request to the telephone terminal of the subscriber 2000 according to the subscriber data managed by the exchange server C (step S34). As a result, an “invite” request from the telephone terminal of the subscriber 2001 reaches the telephone terminal of the subscriber 2000.

  In one embodiment of the present invention, a plurality of exchange servers are grouped in advance. It is desirable that the exchange servers constituting this exchange server group are geographically dispersed in order to reduce the influence of disasters such as earthquakes. Therefore, this exchange server group is called a regional distribution set. The SIP address of the telephone terminal registered in the exchange server constituting the regional distribution set is notified to other subscribers by adding the SIP domain name of the regional distribution set instead of the SIP domain name of the exchange server. When each exchange server receives a message transmitted to a SIP address having the SIP domain name of the regional distribution set of which it is a constituent member, each exchange server configures the SIP domain name of the destination SIP address in the regional distribution set. The message is transferred by replacing it with the SIP domain name of the exchange server.

  FIG. 5 is a diagram showing a system configuration example of the exchange server according to the embodiment of the present invention. As shown in FIG. 5, the exchange server 2 includes a transmission / reception unit 12 for transmitting / receiving data to / from other communication devices via the communication network 4, and a data buffer 14 for storing data to be relayed. The input / output unit 22 for outputting data to the operator and accepting data input from the operator, the regional distribution set management unit 24 for executing processing regarding the regional distribution set, and the data regarding the regional distribution set in a table format A table creating unit 26 for creating, a storage unit 28 for storing various data managed by the exchange server 2, and a control unit 30 for controlling the entire exchange server 2 are included. Of the functions processed by the exchange server 2, the control unit 30 executes all functions not explicitly described in this specification, including the functions processed by a normal exchange server.

  FIG. 6 is a diagram for explaining an embodiment of the present invention. An embodiment of the present invention will be described with reference to FIG. In FIG. 6, it is assumed that the exchange server A, the exchange server B, and the exchange server C constitute a regional distribution set. A regional distribution set is named. For example, it is assumed that the regional distribution set name α is assigned to the regional distribution set including the exchange server A, the exchange server B, and the exchange server C in FIG. For the sake of simplicity, the regional distribution set name is treated as the SIP domain name in the same manner as the exchange server name. Information on the exchange servers constituting the regional distribution set is managed by each exchange server. That is, the regional distribution set table in which A, B, and C are registered in association with α is managed by each of the exchange server A, exchange server B, and exchange server C that are members of the regional distribution set α. FIG. 7 is a diagram showing an example of the regional distribution set table in the embodiment of the present invention. This data is registered in advance in the exchange server 2 by the operator of the exchange server 2. FIG. 8 is a diagram showing an example of a regional distribution set registration screen according to an embodiment of the present invention. The input / output unit 22 displays this on the display screen, and accepts input of the regional distribution set name α and the configuration exchange server names A, B, and C by the operator. In response to an instruction from the regional distribution set management unit 24, the table creation unit 26 creates a regional distribution set table and registers it in the storage unit 28.

  The subscriber can receive by registering with any exchange server. In the example of FIG. 6, a “register” request is transmitted from the telephone terminal of the subscriber 2000 to the exchange server A (step S 42), whereby the telephone terminal of the subscriber 2000 is registered in the exchange server A. Exchange server A registers variable data in the subscriber data of subscriber 2000. As a result of registration with the exchange server A, the SIP address of the telephone terminal of the subscriber 2000 is 2000 @ A. Exchange server A passes the regional distribution set table to the telephone terminal of subscriber 2000. The telephone terminal of the subscriber 2000 notifies the other telephone terminals as not having 2000 @ A as its SIP address but as 2000 @ α with the SIP domain name replaced with α.

  FIG. 9 is a diagram showing a call connection sequence in one embodiment of the present invention. When the subscriber 2001 makes a call to the subscriber 2000, the telephone terminal of the subscriber 2001 transmits an “invite” request having 2000 @ α as a destination SIP address to an arbitrary exchange server. It is assumed that this has reached one of the members of the regional distribution set α (the exchange server B in FIGS. 6 and 9) (step S46). Since the exchange server B is a member of the regional distribution set α, the “invite” request is transferred to each exchange server that is a member of the regional distribution set α according to the regional distribution set table. At this time, the SIP domain name in the destination SIP address is replaced with the SIP domain name of each exchange server. When the “invite” request is transferred to the exchange server A (step S48), the exchange server A transfers the “invite” request to the telephone terminal of the subscriber 2000 according to the subscriber data managed by itself (step S50). As a result, an “invite” request from the telephone terminal of the subscriber 2001 reaches the telephone terminal of the subscriber 2000. When the “invite” request is transferred to the exchange server B (step S52), the exchange server B returns an error because the subscriber 2000 is not registered in itself. When the “invite” request is transferred to the exchange server C (step S54), the exchange server C returns an error because the subscriber 2000 is not registered in itself.

  FIG. 10 is a diagram for explaining an operation when the exchange server is not operating in the embodiment of the present invention. Based on FIG. 10, the operation when the exchange server is not operating in one embodiment of the present invention will be described. Assume that the telephone terminal of the subscriber 2000 is registered in the exchange server A. When the exchange server A becomes inoperable for some reason such as an earthquake, the exchange server A does not accept any message from another communication device. Therefore, even if the telephone terminal of the subscriber 2000 transmits a “register” request to the exchange server A again before the valid period of registration elapses (step S62), a response from the exchange server A cannot be obtained.

  In response to the failure of the registration procedure with the exchange server A, the subscriber 2000 performs the registration procedure with respect to another exchange server (the exchange server C in FIG. 10) that constitutes the same regional distribution set α (step S64). ). As a result, the SIP address of the telephone terminal of the subscriber 2000 becomes 2000 @ C. This exchange server registration change may be set in the telephone terminal of the subscriber 2000 so that it is automatically performed in the event of an emergency. This exchange server registration change allows subscriber 2000 to continue receiving calls. Since the exchange server C which is the registration destination after the registration change is a member of the same regional distribution set α as the exchange server A which is the registration destination before the registration change, the telephone terminal of the subscriber 2000 is compared with other telephone terminals. Thus, it is not necessary to notify 2000 @ α again as its own SIP address.

  FIG. 11 is a diagram showing a call connection sequence when the exchange server is not operating in one embodiment of the present invention. The telephone terminal of the subscriber 2001 transmits an “invite” request with 2000 @ α as a destination SIP address to an arbitrary exchange server. It is assumed that this has reached one of the members of the regional distribution set α (exchange server B in FIGS. 10 and 11) (step S68). Since the exchange server B is a member of the regional distribution set α, the “invite” request is transferred to each member of the regional distribution set α according to the regional distribution set table. At this time, the SIP domain name in the destination SIP address is replaced with the SIP domain name of each exchange server. Even if the “invite” request is transferred to the exchange server A (step S70), no response is returned from the exchange server A. When the “invite” request is transferred to the exchange server B (step S72), the exchange server B returns an error because the subscriber 2000 is not registered in itself. When the “invite” request is transferred to the exchange server C (step S74), the exchange server C transfers the “invite” request to the telephone terminal of the subscriber 2000 according to the subscriber data managed by the exchange server C (step S76). As a result, an “invite” request from the telephone terminal of the subscriber 2001 reaches the telephone terminal of the subscriber 2000. In this way, even if the subscriber 2000 changes the registration from the failed switching server to another switching server in the same group, it is not necessary to issue a SIP address change notification and receives the incoming call addressed to the previous SIP address. be able to.

  In order to realize this, when the exchange server 2 receives a message transmitted to the SIP address having the SIP domain name α of the regional distribution set α of which the exchange server 2 is a constituent member, the exchange server 2 receives the SIP domain name of the destination SIP address. Is replaced with the SIP domain name A of the exchange server A, the SIP domain name B of the exchange server B, and the SIP domain name C of the exchange server C constituting the regional distribution set, respectively, and the message is transferred. Thereafter, α, A, B, and C are replaced with respect to the SIP domain name of the destination SIP address of the related message. For this replacement, the exchange server 2 creates and manages a call state table indicating the state of each call addressed to α, A, B, and C and a related call information table for associating each call. FIG. 12 is a diagram showing an example of a related call information table and a call status table in one embodiment of the present invention.

Next, the details of regional dispersion set management will be described. FIG. 13 is a diagram showing a processing flow when an “Invite” request is received in the embodiment of the present invention. Based on FIG. 13, the flow of processing when an “Invite” request is received in one embodiment of the present invention will be described.
(Step S102) The transmission / reception unit 12 receives an “Invite” request.
(Step S104) The regional distribution set management unit 24 matches the SIP domain name of the destination SIP address of the received “Invite” request with the regional distribution set name registered in the regional distribution set table stored in the storage unit 28. That is, it is checked whether or not the received “Invite” request is addressed to the regional distribution set of which it is a constituent member.
(Step S106) When the received “Invite” request is addressed to the regional distribution set of which it is a constituent member (Step 104: Yes), the table creation unit 26 stores the regional distribution set stored in the storage unit 28. A related call information table ID # x is created based on the data registered in the table.
(Step S108) Next, the table creation unit 26 creates the call state table ID # 1 of the caller based on the data registered in the regional distribution set table stored in the storage unit 28. The “call state” is “waiting for“ 100 ”response”. “Source” is the SIP address of the “Invite” request. “Destination” is the destination SIP address of the “Invite” request. Finally, the table creation unit 26 links the related call information table ID # x and the call state table ID # 1 of the caller to each other.
(Step S110) Further, the table creation unit 26 creates call state tables ID # 2 to ID # 4 of each destination based on the data registered in the regional distribution set table stored in the storage unit 28. The “call state” is “waiting for“ 100 ”response”. “Source” is the SIP address of the “Invite” request. “Destination” uses the SIP domain name of the destination SIP address of the “Invite” request as the SIP domain name of each destination exchange server. Finally, the table creation unit 26 links the related call information table ID # x and the call status tables ID # 2 to ID # 4 of each destination.
(Step S112) The regional distribution set management unit 24 replaces the destination SIP address of the received “Invite” request with the “destination” of the call state tables ID # 2 to ID # 4 of each destination, and after the replacement An “Invite” request is transmitted via the transmission / reception unit 12.
(Step S114) When the received “Invite” request is not addressed to the regional distribution set of which the received “Invite” request is a constituent member (No at Step 104), the control unit 30 performs a normal operation on the received “Invite” request. Perform relay processing.

FIG. 14 is a diagram showing a processing flow when a “180” response is received in the embodiment of the present invention. Based on FIG. 14, the flow of processing when a “180” response is received in one embodiment of the present invention will be described.
(Step S202) The transmission / reception unit 12 receives a “180” response.
(Step S204) The regional distribution set management unit 24 extracts the call state table ID # j (j is any one of 2 to 4) of the destination corresponding to the received “180” response from the storage unit 28.
(Step S206) The regional distribution set management unit 24 checks whether or not there is a link to the related call information table ID # x in the extracted call state table ID # j of the incoming call destination.
(Step S208) When there is a link to the related call information table ID # x in the extracted call status table ID # j of the destination (Step S206: Yes), the regional distribution set management unit 24 extracts the destination The “call state” in the call state table ID # j is changed to “waiting for“ 200 ”response”.
(Step S210) The regional distribution set management unit 24 extracts the call state table ID # 1 of the caller from the storage unit 28.
(Step S212) The regional distribution set management unit 24 checks whether the “call state” in the call state table ID # 1 of the caller is “waiting for“ 200 ”response”. If “waiting for“ 200 ”response” (step S212: Yes), the process is terminated.
(Step S214) When the “call state” of the call state table ID # 1 of the caller is not “waiting for“ 200 ”response” (step S212: No), the regional distribution set management unit 24 calls the call state table ID of the caller The “call state” of # 1 is changed to “waiting for“ 200 ”response”.
(Step S216) The regional distribution set management unit 24 replaces the destination SIP address of the received “180” response with the “destination” of the call state table ID # 1 of the caller, and replaces the “180” response after the replacement. The data is transmitted via the transmission / reception unit 12.
(Step S218) When there is no link to the related call information table ID # x in the extracted call state table ID # j of the destination (Step S206: No), the control unit 30 responds to the received “180” response. On the other hand, normal relay processing is performed.

FIG. 15 is a diagram showing a processing flow when a “200” response is received in one embodiment of the present invention. Based on FIG. 15, the flow of processing when a “200” response is received in one embodiment of the present invention will be described.
(Step S302) The transmission / reception unit 12 receives the “200” response.
(Step S304) The regional distribution set management unit 24 extracts the call state table ID # j (j is any one of 2 to 4) of the destination corresponding to the received “200” response from the storage unit 28.
(Step S306) The regional distribution set management unit 24 checks whether or not there is a link to the related call information table ID # x in the extracted call state table ID # j of the incoming call destination.
(Step S308) When there is a link to the related call information table ID # x in the extracted call state table ID # j of the destination (Step S306: Yes), the regional distribution set management unit 24 extracts the destination The “call state” in the call state table ID # j is changed to “waiting for“ Ack ””.
(Step S310) The regional distribution set management unit 24 uses the call state table ID # i (i = 2, 3, or4, i ≠ j) of each destination other than the extracted call state table ID # j of the destination. The mutual link with the related call information table ID # x is disconnected. That is, the “related call information ID” of the call state table ID # i of each destination is cleared, and each ID # i is cleared from the “destination call state ID” of the related call information table ID # x. Further, the regional distribution set management unit 24 sets “destination” in the call state table ID # i of each destination as the destination SIP address for each destination that has not yet received a response of “200” or more. Send a “Cancel” request.
(Step S312) The regional distribution set management unit 24 extracts the call state table ID # 1 of the caller from the storage unit 28.
(Step S314) The regional distribution set management unit 24 changes the “call state” in the call state table ID # 1 of the caller to “wait for“ Ack ””.
(Step S316) The regional distribution set management unit 24 replaces the destination SIP address of the received “200” response with the “destination” of the call state table ID # 1 of the caller, and replaces the “200” response after the replacement. The data is transmitted via the transmission / reception unit 12.
(Step S318) When there is no link to the related call information table ID # x in the extracted call state table ID # j of the destination (Step S306: No), the control unit 30 responds to the received “200” response. On the other hand, normal relay processing is performed.

  In the above-described embodiment, a plurality of exchange servers are grouped in advance, and the SIP address having the SIP domain name serving as an identifier for identifying the group is notified as the SIP address of the telephone terminal. Since the “Invite” request sent to this SIP address is transferred to each exchange server that constitutes this group, the telephone terminal registered in the exchange server in the group is registered in another exchange server in the group. Even after that, the “Invite” request arrives at this telephone terminal while maintaining the previous SIP address. Thus, according to an embodiment of the present invention, it is possible to provide a communication relay method that facilitates transmission from a failed exchange server to a subscriber whose registration is changed to another exchange server in the same group. .

  The exchange server according to the embodiment of the present invention can be implemented as hardware or computer software. For example, a program for causing a computer to execute the functions of the transmission / reception unit 12, the regional distribution set management unit 24, the table creation unit 26, and the control unit 30 shown in FIG. 5 is created, and the program is read into the memory of the computer. If executed, an exchange server can be realized.

  As shown in FIG. 16, the program for realizing the exchange server according to the embodiment of the present invention is a portable recording medium such as a CD-ROM, CD-RW, DVD-R, DVD-RAM, DVD-RW, or flexible disk. It may be recorded not only on the medium 84 but also on another storage device 88 provided at the end of the communication line 86, a storage device such as a hard disk or RAM of the computer system 82, or the recording medium 90. When the program is executed, the program is loaded and executed on the main memory.

  The components of the exchange server according to the embodiment of the present invention may be realized in any combination. A plurality of constituent elements may be realized as one member, or a single constituent element may be composed of a plurality of members.

It is a figure for demonstrating the example of the IP telephone service by an exchange server. It is a figure which shows the example of subscriber data. It is a figure which shows the example of the subscriber data which the exchange server A manages. It is a figure for demonstrating operation | movement at the time of a non-operating exchange server. It is a figure which shows the system configuration example of the exchange server concerning one Embodiment of this invention. It is a figure for demonstrating one Embodiment of this invention. It is a figure which shows the example of the area dispersion | distribution set table in one Embodiment of this invention. It is a figure which shows the example of the area dispersion | distribution set registration screen in one Embodiment of this invention. It is a figure which shows the call connection sequence in one Embodiment of this invention. It is a figure for demonstrating the operation | movement at the time of the non-operation of the exchange server in one Embodiment of this invention. It is a figure which shows the call connection sequence at the time of the non-operation of the exchange server in one Embodiment of this invention. It is a figure which shows the example of the related call information table and call state table in one Embodiment of this invention. It is a figure which shows the processing flow at the time of "Invite" request reception in one Embodiment of this invention. It is a figure which shows the processing flow at the time of "180" response reception in one Embodiment of this invention. It is a figure which shows the processing flow at the time of "200" response reception in one Embodiment of this invention. It is a figure which shows the example of a computer environment.

Explanation of symbols

2: Exchange server 4: Communication network 12: Transmission / reception unit 14: Data buffer 22: Input / output unit 24: Regional distribution set management unit 26: Table creation unit 28: Storage unit
30: Control unit

Claims (3)

A communication relay method executed by an exchange server that is a member of an exchange server group having plural exchange servers as members,
Storing the domain name of the plurality of exchange servers in association with the domain name of the exchange server group;
Receiving a first call connection request for a communication device;
When the domain name included in the destination address of the first call connection request is the domain name of the exchange server group, the domain name included in the destination address of the first call connection request is Replacing the domain name of the exchange server stored in association with the domain name to generate a second call connection request;
Transmitting the second call connection request to the communication device;
The communication relay method characterized by including. A communication relay program that causes a computer that is a member of an exchange server group having a plurality of exchange servers as members to execute a communication relay method, wherein the communication relay method includes:
Storing the domain name of the plurality of exchange servers in association with the domain name of the exchange server group;
Receiving a first call connection request for a communication device;
When the domain name included in the destination address of the first call connection request is the domain name of the exchange server group, the domain name included in the destination address of the first call connection request is Replacing the domain name of the exchange server stored in association with the domain name to generate a second call connection request;
Transmitting the second call connection request to the communication device;
A communication relay program comprising: A communication relay device that is a member of an exchange server group having a plurality of exchange servers as members;
A storage unit for storing a domain name of the plurality of exchange servers in association with a domain name of the exchange server group;
A transmission / reception unit for transmitting / receiving a call connection request;
When the domain name included in the destination address of the received first call connection request is the domain name of the exchange server group, the domain name included in the destination address of the first call connection request is changed to the exchange server group. An exchange server group management unit for generating a second call connection request in place of the domain name of the exchange server stored in association with the domain name of
A communication relay device comprising: