JP4564523B2 - Communication system and communication terminal - Google Patents

Description

  The present invention relates to a call control device that performs call control between a plurality of communication terminals that perform IP packet communication, a communication terminal, a communication system that includes these, and a call control failure countermeasure method.

  Conventional IP packet communication systems include those shown in FIG.

  This IP packet communication system includes a plurality of communication terminals 7 and 8 that perform IP packet communication, and a call control device 3 that performs call control between the plurality of communication terminals 7 and 8. A plurality of communication terminals 7 and 8 and the call control device 3 are connected by a LAN line 9. Examples of the communication terminals 7 and 8 include an IP telephone, an IP gateway, and an IP / PBX (Private Branch Exchanger) to which a plurality of general telephones are connected.

  The call control device 3 includes a first call control unit 5a, a second call control unit 5b, and a call control management unit 6 that manages these call control units 5a and 5b in order to perform non-stop call service. And a communication interface 4 for performing IP packet communication. In the call control device 3, if the first call control unit 5a is in an operating state, the second call control unit 5b is in a standby state. At this time, the call control management unit 6 constantly monitors whether or not a failure has occurred in the first call control unit 5a in the operating state, and the call owned by the first call control unit 5b. The service setting information and the call control status information are given to the second call control unit 5b as they are. In other words, when the first call control unit 5a acquires the call service information and the call control state information, the information is dead-copied to the second call control unit 5b almost at the same time. Note that the call service setting information is information related to a call service that can be set by each terminal, for example, various services such as an incoming call transfer service for transferring an incoming call to the terminal itself to another terminal. Call control status information is information relating to the status of each terminal, such as which terminal is busy.

  In this call control device 3, when a failure occurs in the first call control unit 5a, the call control management unit 6 immediately detects this failure and owns all the information of the first call control unit 5a. The waiting second call control unit 5b is activated to realize a non-stop call service.

  However, in the above prior art, in addition to the first call control unit 5a, a second call control unit 5b as a spare device is provided, and hardware independent of the two call control units 5a and 5b is provided. Therefore, there is a problem that the apparatus cost is increased. In particular, as described above, when the first call control unit 5a acquires the call service setting information and call control state information of the terminal, the call control management unit 6 sends these information to the second call control unit almost simultaneously. In order to make a dead copy in 5b, it is composed of special hardware and is very expensive.

  The present invention has been made by paying attention to such problems of the prior art, and can suppress a device cost and can cope with a failure in call control, a communication system including the device, and An object is to provide a countermeasure method for a call control failure.

In order to achieve the object, the call control device comprises:
Communication means for performing IP packet communication with a plurality of communication terminals and other call control devices;
Call control means for performing call control of a plurality of the communication terminals;
An operation enable notification indicating that the call control is possible is received from the other call control device via the communication means, and when the operation enable notification cannot be received for a predetermined time or more, the other call control device A monitoring unit that determines that the call control unit is in a disabled state, activates the call control unit in a standby state, and sets the operation state;
It is characterized by having.

Here, the call control device
Setting information related to the call service of a plurality of terminals, the call service setting information used when the call control means performs call control, in the standby state, the other call control device via the communication means It is preferable to include a setting information management means that acquires and manages from the above.

In this case, when the call control means is in operation,
The setting information management means sends the call service setting information managed by the setting information management means to the other call control device via the communication means,
The monitoring means monitors whether or not a failure has occurred in the call control by the call control means, and when the failure has not occurred and the call control is possible, the other call is performed at the predetermined time intervals. When an operation enable notification is sent to the control device, and it is recognized that a failure has occurred in the call control by the call control means, transmission of the operation enable notification to the other call control device is stopped, and the call control It is preferable to change the means from the operation state to the standby state.

In addition, another call control device for achieving the above-mentioned object is:
Communication means for performing IP packet communication with a plurality of communication terminals and other call control devices;
Call control means for performing call control of a plurality of the communication terminals;
It monitors whether or not a failure has occurred in call control by the call control means, and when the failure has not occurred and is in a call control enabled state, it sends an operational notification to the other call control device, and When recognizing that a failure has occurred in the call control by the control means, the monitoring means for stopping the transmission of the operation enable notification to the other call control device and changing the call control means from the operating state to the standby state When,
It is characterized by having.

Here, the call control device
The setting information on the call service of the plurality of terminals, which manages call service setting information used when the call control unit performs call control, and in the operation state, at regular intervals via the communication unit It is preferable to further comprise setting information management means for sending the call service setting information to the other call control device.

Each of the above call control devices
When the call control means is in an operating state, the monitoring means preferably notifies the plurality of communication terminals that the call control is possible via the communication means.

Further, each of the above call control devices
When the call control means is in an operating state, the monitoring means sends a response request from any one of the plurality of communication terminals to a call control apparatus that is currently in an operation state in which call control is possible. When received via the means, the IP address of the call control device is preferably transmitted to the communication terminal that has transmitted the response request.

A communication terminal for achieving the object is as follows:
Communication means for performing IP packet communication with other communication terminals and a plurality of call control devices;
When one call control device of the plurality of call control devices is in an operational state in which call control is possible, and when the other call control device is in a standby state, from the one call control device via the communication means When it is received every certain time that it is in an operational state in which call control is possible, the one call control device in the operational state is monitored, and the fact that it is in an operational state in which call control is possible cannot be received for a certain period of time or more A monitoring means for recognizing that a failure has occurred in the call control by the one call control device and releasing the call control connection to the one call control device to the communication means;
It is characterized by having.

  Here, the monitoring unit of the communication terminal is unable to receive the call control enabled operation state for the predetermined time or more, and after releasing a call control connection to the one call control device, It is preferable to request a response from a call control apparatus that is currently in an operation state in which call control is possible, via the communication means.

In addition, an operation program of the call control device for achieving the object is as follows:
A call control procedure for performing call control of a plurality of communication terminals;
Accepting an operation enable notification indicating that the call control enabled state is received from another call control device, and determining that the other call control device is in a call control disabled state when the operation enable notification cannot be received for a predetermined time or more, A monitoring procedure for activating the call control means in a standby state to put it in an operating state;
Is executed by an arithmetic unit.

An operation program of another call control device for achieving the object is as follows:
A call control procedure for performing call control of a plurality of communication terminals;
It monitors whether or not a failure has occurred in the call control in the call control procedure, and when the failure has not occurred and is in a call control enabled state, an operation ready notification is sent to another call control device, When recognizing that a failure has occurred in the call control in the control procedure, monitoring of the call control procedure from the operation state to the standby state is stopped by stopping transmission of the operation enable notification to the other call control device. Procedure and
Is executed by an arithmetic unit.

In the operation program of the communication terminal for achieving the object,
When one call control device of a plurality of call control devices is in an operational state in which call control is possible and another call control device is in a standby state, the other call control device is connected to another call terminal. A call control requesting procedure for requesting call control for communication via a communication means;
Receiving from the one call control device that the call control is in an operable state at regular intervals, monitoring the one call control device in the operation state, and indicating that the call control is in an operable state If it cannot be received for a certain period of time or longer, it recognizes that a failure has occurred in call control by the one call control device, causes the communication means to release the call control connection to the one call control device, and After releasing the call control connection to one call control device, among the plurality of call control devices, a response from the call control device that is currently in the call control enabled state is sent via the communication means. The required monitoring procedures;
It is characterized by having the arithmetic unit execute. Also, a countermeasure method for a call control failure to achieve the above-mentioned purpose is as follows:
A first call control device and a second call control device capable of IP packet communication with a plurality of communication terminals;
The first call control device includes:
A call control step for performing call control of a plurality of the communication terminals;
Whether or not a failure has occurred in the call control in the call control step is monitored, and when the failure has not occurred and the call control is possible, the second call control device can operate at regular intervals. When a notification is sent and it is recognized that a failure has occurred in the call control in the call control process, the transmission of the operation enable notification to the second call control device is stopped and the call control process is operated. A monitoring process for switching from a state to a standby state;
Run
The second call control device includes:
A call control step for performing call control of a plurality of the communication terminals;
When a notification indicating that the call control is possible is received from the first call control device, and the operation enable notification cannot be received for the predetermined time or longer, the first call control device is in a call control disabled state. A monitoring step of activating the call control step in the standby state to bring it into an operating state;
Is executed.

Here, in the countermeasure method for the above call control failure,
Among the first call control device and the second call control device, in the monitoring step of the call control device in which the call control step is in operation, call control is possible for a plurality of the communication terminals. Notify every time that it is in a state,
When the plurality of communication terminals cannot receive the operational state in which the call control is possible for the predetermined time or longer, the call control is currently performed between the first call control device and the second call control device. Request a response from a call control device in a possible operational state,
Among the first call control device and the second call control device, in the monitoring process of the call control device that is currently in an operation state in which the call control is possible, in response to the response requests from the plurality of communication terminals It is preferable that the IP address of the call control device is transmitted to the communication terminal that has transmitted the response request.

  According to the present invention, even if a failure occurs in the active call control device of the two call control devices, the call control device in the standby state becomes the active state and performs call control between the communication terminals. Therefore, damage due to call control failure can be minimized. In addition, since it is confirmed by communication whether or not call control is possible between the two call control devices, in addition to the two call control devices, call control management for managing these separately. An apparatus becomes unnecessary, and the apparatus cost can be suppressed.

  Hereinafter, various embodiments of an IP packet communication system according to the present invention will be described with reference to the drawings.

  First, an IP packet communication system as a first embodiment according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the IP packet communication system according to the present embodiment includes first and second communication terminals 20, 28, and 29 that perform IP packet communication and first and second that perform call control between the plurality of communication terminals. Call control devices 10a and 10b. A plurality of communication terminals 20, 28, 29 and call control devices 10a, 10b are connected to each other by a LAN line 9. In this embodiment, one of the plurality of communication terminals 20, 28 and 29 is the IP gateway 20, and the rest are the IP telephones 28 and 29.

  Each of the first and second call control devices 10a and 10b includes communication interfaces 11a and 11b for performing IP packet communication, and call control units 12a and 12b for actually performing call control between the communication terminals. A monitoring unit 13a that monitors the states of the call control units 12a and 12b and the other call control devices 10b and 10a, and a setting information management unit 14a that manages setting information related to the call control service of each of the terminals 20, 28, and 29. Storage units 15a and 15b for storing call service setting information, IP addresses of the respective communication terminals, and the like.

  The monitoring units 13a and 13b monitor the call control units 12a and 12b and the communication interfaces 11a and 11b, and can operate to indicate that the call control is possible via the communication interfaces 11a and 11b if there is no failure. A notification is sent to the other call control device. In addition, the other call control device receives an operable notification via the communication interfaces 11a and 11b. The monitoring units 13a and 13b are based on the monitoring results of the call control units 12a and 12b and the communication interfaces 11a and 11b and the operational notification from the other call control device, and the call control units 12a and 12b and the setting information management unit 14a, 14b is switched from the standby state to the operational state, or from the operational state to the standby state.

  In the operational state, the setting information management units 14a and 14b transmit the call service setting information stored in the storage units 15a and 15b to the other call control device via the communication interfaces 11a and 11b. In this case, call service setting information is acquired from the other call control device and registered in the storage units 15a and 15b.

  Each communication terminal 20, 28, 29 converts a communication interface 21 for performing IP packet communication and an IP packet received by the communication interface 21 into a voice signal and the like, while converting a voice signal and the like into an IP packet. The encoder / decoder 22, the A / D converter 23 that converts the audio signal decoded by the encoder / decoder 22 into an analog signal, and the states of the two call control devices 10 a and 10 b are monitored. And a monitoring unit 25. When the communication terminal is the IP gateway 20, an interface 24 for transmitting / receiving an audio signal or the like to / from the PBX or the like is connected to the A / D converter 23. When the communication terminals are IP telephones 28 and 29, a handset or the like is connected to the A / D converter.

  Next, the operation of the communication system of the present embodiment described above will be described with reference to FIG. In the figure, by the initial setting, the call control unit 11a of the first call control device 10a is in an operating state, the first call control device 10a functions as an active system, and the call of the second call control device 10b. It is assumed that the control unit 11b is set in a standby state so that the second call control device 10b functions as a standby system. Further, it is assumed that the communication terminal 20 is in a connection operation with respect to the first call control device 10a working as an active system.

  The monitoring unit 13a of the first call control device 10a, which is the active system, periodically monitors its own call control unit 12a and the communication interface 11a to confirm that the call control is possible, and the communication interface 11a. Then, an operation enable notification is transmitted to the second call control device 10b via the LAN line 9 (step 1). In addition, the monitoring unit 13b of the second call control device 10b, which is a standby system, also periodically transmits an operation enable notification to the first call control device 10a (step 2). In addition, the setting information management unit 14a of the first call control device 10a periodically transmits call service setting information of each communication terminal stored in the storage unit 15a via the communication interface 11a and the LAN line 9. Transmit to the second call control device 10b (step 3). Note that the call service setting information of each communication terminal 20 is set by an operation by a user or the like in each communication terminal 20, and this information is set information management of the call control device 10a by call control communication (step 4) described later. To the unit 14a.

  When the communication terminal 20 makes a call with another communication terminal, call control communication is performed with the call control device 10a that the communication terminal 20 recognizes as an active system, that is, the communication terminal 20 Call control device 10a is requested to perform call control between the communication terminal and another communication terminal (step 4). When a communication line with another communication terminal is established by this call control communication, a call can be made with the other communication terminal.

The monitoring unit 13a of the active call control device 10a periodically monitors its own call control unit 12a and the communication interface 11a and confirms that the call control is possible, as in the case of sending the operation enable notification. Then, it indicates that the call control is possible through the communication interface 11a and the LAN line 9, and transmits an operation confirmation request for requesting the response to each communication terminal 20 (step 5). When receiving the operation confirmation request, the monitoring unit 25 of the communication terminal 20 recognizes that the operation confirmation request source is the active system. Then, as an answer to the operation confirmation request, an operation confirmation response is transmitted to the active call control device 10a (step 6).
In other words, the active system call control device 10a periodically transmits, for example, every 5 seconds, an operation enable notification and call service setting information to the standby system call control device 10b (steps 1 and 3), and the standby system call control. The device 10b periodically transmits an operation enable notification to the active call control device 10a (step 2). Further, the active call control device 10a periodically transmits an operation confirmation request to each communication terminal 20 (step 5).

  As described above, whether the two call control devices 10a and 10b transmit the operation ready notification to the other call control devices 10b and 10a, so that the other call control device is in a state in which call control is possible. You can recognize whether or not. Further, the call service setting information can be shared by the active call control device 10a periodically transmitting the call service setting information to the standby call control device 20b. In addition, when the active call control device 10a periodically transmits an operation check request, each terminal 10 can recognize which call control device is currently active.

  When a failure occurs in the call control unit 12a or the communication interface 11a of the active call control device 10a (step 7), the monitoring unit 13a of the active call control device 10a recognizes this failure, and the current standby call control device. The operation permission notification to 10b and the operation confirmation request to each communication terminal are stopped, the call control unit is set in a standby state, and the standby system is switched (step 8).

  Since the monitoring unit 13b of the second call control device 10b, which is the standby system, initially does not receive an operation permission notification from the first call control device 10a, which is the active system, for the first period, Recognizing that a failure has occurred in the call control device 10a, the call control unit 12b, which has been in a standby state, is put into an operation state, and the second call control device 10b is switched to the operation system (step 9).

  In addition, since the monitoring unit 25 of each communication terminal 20 does not receive an operation confirmation request for a certain period from the first call control device 10a that was initially active, the first call control device 10a. Recognizing that a failure has occurred, the connection with the first call control device 10a is released (step 10).

  The monitoring unit 25 of each communication terminal 20 transmits a search response request by multicast together with the IP address of the terminal itself in order to search for a call control device capable of call control (step 11). In response to this search response request, the first call control device 10b switched to the standby system does not respond, and the monitoring unit 13b of the second call control device 10b switched to the active system communicates with the search response request. The IP address of the second call control device 10b is transmitted to the terminal 20 together with the search response so that the call control device 10b currently in operation is recognized (step 12), and the communication terminal that requested the search response 20 IP addresses are stored (step 15). The communication interface 21 of the communication terminal 20 that has received the IP address of the second call control device 10b together with the search response stores this IP address (step 13), and then the second call control device that has become the active system. Connection processing for call control communication is performed with 10b (step 14).

  The monitoring unit 13b of the second call control device 10b that has been switched to the active system periodically performs its own call control unit 12b and communication interface 11b in the same manner as when the first call control device 10a is the active system. Is confirmed to be in a call controllable state, an operation ready notification is transmitted to the first call control device 10a as a standby system (step 21), and an operation confirmation request is transmitted to each communication terminal. (Step 25). In response to this operation confirmation request, each communication terminal 20 returns an operation confirmation response to the second call control apparatus 10b that is currently in operation (step 26). The setting information management unit 14b of the second call control device 10b transmits call service setting information to the first call control device 10a (step 23). The monitoring unit 13a of the first call control device 10a, which is a standby system, monitors its own call control unit 12a and the communication interface 11a. Operational notification is periodically transmitted to the call control device 10b.

  When the communication terminal 20 makes a call with another communication terminal, as in step 4, the call control device recognized by the monitoring unit of the communication terminal 20 as the active system, in this case, the second call Call control communication is performed with the control device 10b (step 24). When a communication line with another communication terminal is established by this call control communication, a call can be made with the other communication terminal.

  Note that the processing in steps 11 to 14 described above is performed as initial processing so that each communication terminal 20 recognizes the active call control device even when each communication terminal 20 is started up. Specifically, as shown in the flowchart of FIG. 3, first, the monitoring unit 25 of the communication terminal 20 transmits a search response request by multicast together with the IP address of the terminal itself in order to search for a call control device that can perform call control. (Step 11). Subsequently, the monitoring unit 25 waits for reception of a search response from the active call control device in response to this search response request (step 12). When this search response is received, the monitoring unit 25 is sent together with the search response. The IP address of the active call control device is registered in the storage unit 26 (step 13). Further, the monitoring unit 25 causes the communication interface 21 to execute a connection process for performing call control communication with the active call control device (step 14).

  Thereafter, when the communication terminal 20 makes a call with another communication terminal, call control communication is performed with the call control device stored as the active system in the storage unit 26 of the communication terminal 20 (step). 24). Further, the monitoring unit 25 determines whether or not an operation check request from the active call control device is periodically received (step 25). If the operation check request cannot be received, the monitoring unit 25 returns to step 11; If the operation confirmation request has been received, an operation confirmation response is sent to the active call control device (step 26).

  Here, the operation of each call control device will be described together with FIG.

  If there is no failure, the active call control device periodically sends an operational notification and call service setting information to the standby call control device, regardless of whether or not there is a failure in the standby call control device. To do. Also, an operation confirmation request is transmitted to the communication terminal, a search response is returned in response to the search response request, and a call service instruction at the time of call control connection is given.

  When a failure occurs in the active call control device, this active system is transferred to the standby system, and the standby system is moved to the active system, the call control device moved from the standby system to the active system is changed from the active system to the standby system. Regardless of whether the call control device has a fault or not, the operation control notification and call service setting information are periodically transmitted to the transferred call control device. Also, an operation confirmation request is transmitted to the communication terminal, a search response is returned in response to the search response request, and a call service instruction at the time of call control connection is given.

  When there is no failure, the standby call control device periodically transmits an operation enable notification to the active call control device. The transmission of call service setting information to the active call control device, the transmission of an operation confirmation request to the communication terminal, the search response to the search response request from the communication terminal, and the call service instruction at the time of call control connection are all active call control. It is performed by the device, and the standby call control device is not performed.

  When a failure occurs in the active call control device, and this active system is transferred to the standby system, the call control device that has been transferred from the active system to the standby system receives an operation enable notification and call service setting information for the active call control device. Do not send. Furthermore, the transmission of an operation confirmation request to the communication terminal, the search response to the search response request from the communication terminal, and the call service instruction at the time of call control connection are not performed.

  As described above, in this embodiment, even if a failure occurs in the active call control device 10a among the two call control devices 10a and 10b, the standby call control device 10b becomes the active system, and each communication Since terminal-to-terminal call control is performed, damage due to call control failure can be minimized. In addition, since the two call control devices 10a and 10b confirm whether or not the call control is possible by communication, in addition to the two call control devices 10a and 10b, these are separately provided. The call control management device for managing the device becomes unnecessary, and the device cost can be reduced.

  Next, an IP packet communication system as a second embodiment according to the present invention will be described with reference to FIGS.

  In the IP packet communication system of this embodiment, as shown in FIG. 5, two communication bases A and B are connected via a WAN (Wide Area Network) 1 that is an IP network and relay devices 2a and 2b such as routers. It is what has been. Each of the communication bases A and B includes call control devices 10a and 10b, the above-described relay devices 2a and 2b, and a plurality of communication terminals 20a, 29a, 20b, and 29b. The call control devices 10a and 10b, the relay devices 2a and 2b, and the plurality of terminals 20a, 29a, 20b, and 29b are connected to each other by LAN lines 9a and 9b. That is, in the first embodiment, two call control devices and a plurality of communication terminals are provided in a certain base. However, in the first embodiment, two communication bases are respectively provided via the WAN 1. A call control device for each unit and a plurality of communication terminals are provided.

  As in the first embodiment, the call control devices 10a and 10b at the respective bases A and B are calls that actually perform call control between the communication interfaces 11a and 11b for performing IP packet communication and the communication terminals. Control units 12a and 12b, monitoring units 13a and 13b that monitor the states of the call control units 12a and 12b and the other call control device, and a setting information management unit 14a that manages setting information related to the call control service of each terminal. 14b and storage units 15a and 15b for storing call service setting information and the like.

  Similarly to the first embodiment, the communication terminals 20a and 20b of the respective bases A and B also use the communication interface 21 for performing IP packet communication and the IP packet received by the communication interface 21 as a voice signal or the like. An encoding / decoding unit 22 that converts an audio signal or the like into an IP packet, and an A / D converter 23 that converts the audio signal decoded by the encoding / decoding unit 22 into an analog signal, , A monitoring unit 25 for monitoring the states of the two call control devices, and a storage unit 26.

  Next, the operation of the communication system of the present embodiment described above will be described with reference to FIG. In the figure, it is assumed that the first call control device 10a at the site A functions as an active system and the second call control device 10b at the site B functions as a standby system by the initial setting. . In addition, it is assumed that the communication terminals 20a and 20b at the respective bases A and B are connected to the first call control device 10a working as an active system.

  As in the first embodiment, the monitoring unit 13a of the first call control device 10a, which is the active system, notifies the operation enable notification and the call of each communication terminal via the communication interface 11a, the relay devices 2a and 2b, and the WAN1. The service setting information is transmitted to the second call control device 10b which is a standby system (steps 31 and 33). In addition, the monitoring unit 13b of the second call control device 10b, which is a standby system, also periodically sends an operation enable notification to the first call control device 10a in the same manner as described above (step 32).

  When the communication terminals 20a and 20b at the bases A and B make a call with the other communication terminals 20b and 20a, a call is made with the call control device 10a that the communication terminals 20a and 20b recognize as an active system. Control communication is performed (steps 34a and 34b).

  The monitoring unit 13a of the active call control device 10a at the site A transmits an operation confirmation request to the communication terminals 20a and 20b at the sites A and B (steps 35a and 35b). When receiving the operation confirmation request, the monitoring units 13a and 13b of the communication terminals 20a and 20b at the respective bases A and B recognize that the operation confirmation request source is an active system and operate as a response to the operation confirmation request. A confirmation response is transmitted to the active call control device 10a (steps 36a and 36b).

  That is, the processes from step 31 to 36b are the same as the processes from step 1 to 6 in the first embodiment.

  When a failure occurs in the relay line between the bases A and B (step 37), the monitoring unit 13a of the active call control device 10a does not recognize the failure of its own call control unit 12a. First, an operation permission notification is transmitted to the standby call control device 10b at the site B (step 38), and an operation confirmation request is transmitted to the communication terminals 20a and 20b at the sites A and B (steps 40a and 40b). In addition, the monitoring unit 13b of the standby call control device 10b at the site B also transmits an operation confirmation request to the active call control device 10a at the site A (step 39). However, since a failure has occurred in the relay line between the bases A and B, the operation enable notification and the operation confirmation request from the active call control device 10a of the base A to the base B do not reach the base B (step 38). , Step 40b), and the notification of the availability of operation from the standby call control device 10b at the site B to the site A does not reach the site A (step 39).

  Since the active call control device 10a at the site A cannot receive the operation enable notification from the standby call control device at the site B, it recognizes that a failure has occurred at the site B, and thereafter only the communication terminal 20a at the site A. Then, an operation confirmation request is transmitted (step 40a), and an operation confirmation response is received from this terminal 20a (step 41a). Furthermore, call control communication is performed only with the communication terminal at the site A (step 42a). However, the operation confirmation request is transmitted to the base B periodically thereafter (steps 38, 38,...).

  On the other hand, since the monitoring unit 13b of the standby call control device 10b at the site B does not receive an operation permission notification from the active call control device 10a at the site A for a certain period (step 38), the operation of the site A Recognizing that a failure has occurred in the system call control device 10a, the call control unit 12b, which has been in a standby state, is put into an operation state, and the second call control device 10b, which is a standby system, is switched to the operation system (step 43). ).

  In addition, since the monitoring unit 25 of each communication terminal 20b at the site B does not receive an operation confirmation request for a certain period from the first call control device 20a that was initially active (step 40b), the site Recognizing that a failure has occurred in the first call control apparatus 10a of A, the connection with the first call control apparatus 10a is released (step 41).

  Then, the monitoring unit 25 of each communication terminal 20b at the base B transmits a search response request by multicast together with the IP address of the terminal itself in order to search for a call control device capable of call control (step 44). In response to this search response request, the monitoring unit 13b of the second call control device 10b switched to the active system sends the second call control together with the search response to the communication terminal 20b of the base B that has made the search response request. The IP address of the device 10b is transmitted to recognize the call control device 10b that is currently in operation (step 45), and the IP address of the communication terminal 20b that requested the search response is stored (step 48). The communication interface 21 of the communication terminal 20b that has received the IP address of the second call control device 10b together with the search response stores the IP address in the storage unit 25 (step 46), and then the second interface that has become the active system. Connection processing for call control communication is performed with the call control device 10b (step 47).

  The monitoring unit 13b of the second call control device 10b that has been switched to the active system periodically performs its own call control unit 12b and communication interface 11b in the same manner as when the first call control device 10a is the active system. Is confirmed to be in a call controllable state, an operation enable notification is transmitted to the first call control device 10a at the site A (step 52), and an operation confirmation request is sent to each communication terminal 20b at the site B. Is transmitted (step 50b). In response to this operation confirmation request, each communication terminal 20b at the site B returns an operation confirmation response (step 51b).

  As described above, when a failure occurs in the trunk line, the first call control device 10a at the site A maintains the active system, but only as a call control device for each communication terminal 20a at the site A. The second call control device 10b of the base B that was initially a standby system functions as a call control device only for each communication terminal 20b of the base B, although it is switched to the active system. That is, when a failure occurs in the relay line, the call control device at each site becomes the active call control device at each site.

  Next, the operation when the failure of the trunk line is recovered will be described with reference to FIG.

  When the failure of the trunk line is recovered (step 55), the operation ready notification from the second call control device 10b at the site B reaches the first call control device 10a at the site A (step 56). Similarly, the notification that the operation is possible from the first call control device 10a at the site A reaches the second call control device 10b at the site B (step 57).

  As a result, the monitoring unit 13b of the second call control device 10b at the base B recognizes that the failure of the first call control device 10a at the base A, which was the active system, has been recovered, and is in an operating state. Then, the call control unit 12b is set in a standby state, and the second call control device 10b, which is the active system, is switched to the standby system (step 58). Then, as a standby system, an operation enable notification is transmitted to the first call control device 10a at the site A (step 60). Note that the monitoring unit 13b of the second call control device 10b at the site B does not transmit an operation confirmation request to each communication terminal 20b at the site B from the time of switching to the standby system.

  In addition, the monitoring unit 13b of the first call control device 10a at the site A transmits an operation enable notification that has been periodically transmitted even during the occurrence of a failure to the second call control device 10b at the site B (step 57). When the operation is notified from the second call control device 10b at the site B (step 60), the second call control device 10b recognizes that the second call control device 10b has recovered, and the setting information management unit of the first call control device 10a 14a starts transmitting the call service setting information to the second call control device 10b at the base B (step 61).

  On the other hand, since the monitoring unit 25 of the communication terminal 20b at the site B does not receive an operation confirmation request for a certain period from the second call control device 10b that has been the active system until now (step 50b), the site B Recognizing that a failure has occurred in the second call control device 10b, the connection with the second call control device 10b is released (step 62).

  Then, the monitoring unit 25 of each communication terminal 20b at the base B transmits a search response request by multicast together with the IP address of the terminal itself in order to search for a call control device capable of call control (step 63). In response to this search response request, the monitoring unit 13a of the first call control device 10a that has become the active system again sends the first response together with the search response to the communication terminal 20b of the base B that has made the search response request. The IP address of the call control device 10a is transmitted to recognize the call control device 10a that is currently in operation (step 64), and the IP address of the communication terminal 20b that requested the search response is stored (step 68). The communication interface 21 of the communication terminal 20b that has received the IP address of the first call control device 10a together with the search response stores this IP address (step 65), and then the first call control device that has become the active system. Connection processing for call control communication is performed with 10a (step 67).

  Thereafter, the first call control device 10a at the site A transmits an operation check request to the communication terminals 20a and 20b at the sites A and B in the same manner as before the failure of the trunk line shown in FIG. (Steps 35a and 35b), operation confirmation responses are received from the communication terminals 20a and 20b at the bases A and B (Steps 36a and 36b). Further, the first call control device 10a transmits the operation enable notification and the call service setting information to the second call control device 10b which has become the standby system again (steps 31 and 33), and this second call control device. An operation enable notification is received from 10b (step 32).

  As described above, in this embodiment, even if a failure occurs in a relay line between two bases, the call control device provided at each base becomes an active system, and each communication terminal in each base Because call control is performed, damage caused by a trunk line failure can be minimized. Also, even if a failure occurs in the trunk line and the call control device that was the standby system is switched to the active system, the call service setting information is acquired from the call control device that was the active system from the beginning. The same service can be provided at the base.

  In the present embodiment, when a failure occurs in the first call control device 10a, which is the active system, the second call control device 10b becomes the active system as in the first embodiment. The second call control device 10b performs call control of the communication terminals 20a and 20b at the bases A and B. Therefore, also in this embodiment, the same effect as that of the first embodiment can be obtained.

  Moreover, in this embodiment, although the example which provided the call control apparatuses 10a and 10b in the two bases A and B was shown, this invention is not limited to this, respectively. A call control device may be provided. In this case, priorities are determined in advance for the standby call control devices at a plurality of bases, and when a failure occurs in the active call control device at one base, One should be active.

It is a functional block diagram of the communication system in a 1st embodiment concerning the present invention. It is a sequence diagram of the communication system in 1st Embodiment which concerns on this invention. It is a flowchart which shows the operation | movement from the time of starting of the communication terminal in 1st Embodiment which concerns on this invention. It is explanatory drawing which shows the operation | movement in each state of the call control apparatus in 1st Embodiment which concerns on this invention. It is a circuit block diagram of the communication system in 2nd Embodiment which concerns on this invention. It is the sequence diagram (the 1) of the communication system in 2nd Embodiment which concerns on this invention. It is the sequence diagram (the 2) of the communication system in 2nd Embodiment which concerns on this invention. It is a functional block diagram of the conventional communication system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... WAN, 2a, 2b ... Relay apparatus, 3, 10a, 10b ... Call control apparatus, 9, 9a, 9b ... LAN line, 11a, 11b ... Communication interface, 12a, 12b ... Call control part, 13a, 13b ... Monitoring 14a, 14b ... setting information management unit, 15a, 15b ... storage unit, 20, 20a, 20b, 28, 29, 29a, 29b ... communication terminal, 21 ... communication interface, 22 ... encoding / decoding unit, 25 ... monitoring unit, 26 ... storage unit.

Claims (4)

One active call control device that performs call control between a plurality of communication terminals that perform IP packet communication, and at least one standby call control device that can be connected to the active call control device via a relay line In the communication system provided,
The operational call control device is:
Communication means for performing IP packet communication between the plurality of communication terminals and the standby call control device via the relay line, call control means for performing call control of the plurality of communication terminals, and the communication means. through it, receiving the operation-friendly notification indicating that the call control state from the standby system call control apparatus, if said operating friendly notification is not received a certain time or more has a monitoring means for maintaining the operational state, the ,
The standby call control device includes:
Communication means for performing IP packet communication between the plurality of communication terminals and the active call control device via the relay line, call control means for performing call control of the plurality of communication terminals, and the communication means. through it, to receive an operation-friendly notification indicating that the call control state from the active system call control apparatus, if said operating friendly notification is not received a certain time or more, it activates the call control means wait state And a monitoring means for setting the operation state.
A communication system characterized by the above. The communication system according to claim 1 ,
The monitoring means of the standby call control device can perform call control from the active call control device via the communication means when the call control means of the standby call control device is in an operating state. When receiving the operable notification indicating the state, the call control means is placed in a standby state.
A communication system characterized by the above. A communication terminal that is controlled by one of the active call control device and the standby call control device and performs IP packet communication with another communication terminal in the communication system according to claim 1 or 2. And
A communication means for performing IP packet communication with the other communication terminal , the active call control device and the standby call control device ;
When one call control device of the active call control device and the standby call control device is in an operational state in which call control is possible, and when the other call control device is in a standby state, via the communication means, Receiving from the one call control device that the call control is in an operable state at regular intervals, monitoring the one call control device in the operation state, and indicating that the call control is in an operable state If the call cannot be received for a certain period of time, it is recognized that a failure has occurred in call control by the one call control device , and a new call is established between the active call control device and the standby call control device. Monitoring means for obtaining an IP address of the call control device from the call control device in a controllable operating state via the communication means;
A communication terminal comprising: The communication terminal according to claim 3,
If the monitoring means cannot receive the call control enabled operation state for a certain period of time or more, the monitoring means releases a call control connection to the one call control device, and among the plurality of call control devices, Requesting a response from the call control device in the operation state capable of call control via the communication means,
A communication terminal characterized by that.

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