JP2010153958A - Distributed ip-pbx system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the maintenance operation of an IP-PBX installed at a remote site. <P>SOLUTION: Remote nodes 40 and 50 are connected through an IP network 10 to a center node 30, the center node 30 performs the operation monitoring and fault monitoring of the entire system by unitarily managed station data, and the remote nodes 40 and 50 cooperate as one system under the control of the center node 30. Even when communication with the IP-PBX 1a disposed in the center node 30 is interrupted due to an IP network fault or the like, since the IP-PBXes 1b and 1c disposed in the remote sites 40 and 50 are autonomously operated, telephone call origination and transmission inside the remote sites 40 and 50 are secured without installing a backup device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a distributed IP-PBX (Internet Protocol-Private Branch Exchange: IP) in which IP-PBXs are distributed and distributed over a plurality of geographically dispersed sites and combined on an IP network to operate as one large-scale system. (Private Branch Exchange) system.

  Conventional distributed IP-PBX systems of this type generally connect a plurality of geographically separated sites via an IP network, and can handle telephones installed at the plurality of sites as extension telephones of the same extension telephone system. I am doing so. For example, in the system described in Patent Document 1, the main site has an IP-PBX, the remote site has a remote device and a backup PBX, and the IP-PBX and the remote device are connected via an IP network.

  The remote device receives the IP signal transmitted from the IP-PBX, extracts the call signal from the IP signal, transmits the call signal to the transmission destination in the remote site, and from the telephone accommodated by itself. The received call signal is converted into an IP signal and transmitted to the IP-PBX at the main site. The IP-PBX changes the destination of the IP signal received from the remote device to the remote device that accommodates the destination of the call signal stored in the IP signal and transmits the IP signal. When a failure occurs in the IP-PBX at the main site or the communication path, the backup exchange installed at the remote site replaces the IP-PBX at the main site and controls the extension in the remote site. The technique described in Patent Document 1 is characterized in that even if a call is made between extensions within a remote site, the connection is always made via the IP-PBX at the main site.

  Further, Patent Document 2 treats station data common to IP-PBXs at each site as network station data, so that even if the physical interface between PBXs is trunk connection, call control similar to that between extensions is performed. Thus, a technique for providing services equivalent to those accommodated in one PBX to all subscribers in the network is disclosed.

  This technology is characterized in that a specific IP-PBX in a distributed node switching network also serves as a network management node, and the switching connection processing in the node is processed only by the call control processing device of the node. Even if the logical connection with all other nodes is disconnected in the logical connection management circuit, the exchange connection processing is possible by the autonomous operation of the node.

  On the other hand, the IP terminal group backup method in the technologies described in Patent Document 1 and Patent Document 2 has already been realized by the conventional technology. Examples of such an IP-PBX backup system are described in Patent Document 3 and Patent Document 4, for example. These IP-PBX backup systems are composed of an IP-PBX installed at the main site, an IP terminal device group connected to the network, and a backup device that holds terminal data of the IP terminal device group in the network. And works as follows.

  That is, the backup device is installed at the remote site, and when the IP-PBX at the main site becomes unable to control the IP terminal / device installed at the remote site, the backup device starts operation on behalf of the IP-PBX. Therefore, it is possible to continuously operate components such as a group of IP terminal devices at the remote site within the remote site.

Japanese Patent Laying-Open No. 2006-67372 (pages 4 to 5, FIG. 1) Japanese Patent Laid-Open No. 10-210156 (pages 5-7, FIG. 5) Japanese Patent Laying-Open No. 2005-006121 (pages 4-5, FIG. 1) JP 2007-88544 A (page 3 to page 5, FIG. 7)

  However, in the technology described in Patent Document 1, a remote device is installed to accommodate a conventional terminal (hereinafter referred to as a “legacy terminal”) such as an analog telephone or an ISDN telephone at a remote location. A device for making a legacy terminal appear as an IP terminal. And since it does not have a switching function, a control signal is always transmitted / received via the IP-PBX at the main site even if the call is between extensions at a remote site. There is a problem that. In addition, it is possible to adopt an embodiment in which an IP-PBX installed at each site performs switching within each site as a remote site backup switch when a communication failure with the main site occurs. Is a problem.

  In the technique described in Patent Document 2, network station data (information common to all IP-PBXs constituting the system) is used to operate a plurality of distributed IP-PBXs as if they were one system. It is managed in common at each site's IP-PBX, but information unique to each site must be managed individually at each site by local station data (information unique to each IP-PBBX constituting the system). However, there is a problem that the amount of maintenance work at each site increases. In addition, external trunks such as leased line circuit trunks can be used in common with the network, but intra-station trunks such as three-party conference trunks are set not by network station data but by local station data that is unique to each site. Therefore, there is a problem that it cannot be used commonly in each node constituting the network.

  In addition, the technologies described in Patent Document 3 and Patent Document 4 are configured to back up only a group of IP terminals installed at a remote site, and legacy terminals such as analog telephones and ISDN telephones cannot be installed at remote locations. . Further, for the convenience of installing at the remote site as a backup device in the event of a failure in the communication path between the main site IP-PBX or the main site-remote site, the communication path between the main site IP-PBX or the main site-remote site As long as no failure occurs, it cannot be in an operating state, and cannot operate as a plurality of IP-PBXs distributed at remote sites to form one large-scale IP-PBX. Further, it is problematic in terms of introduction cost to make a capital investment for a backup device that cannot be in an operating state unless a failure occurs.

  Therefore, the present invention has been made in view of the above problems in the prior art, and can be constructed as one large capacity system by combining a plurality of geographically dispersed IP-PBXs on an IP network. Another object of the present invention is to provide a distributed IP-PBX system that requires a small amount of maintenance work, can reduce the cost of introducing a backup device, and does not restrict service functions.

  In order to achieve the above object, the present invention provides a distributed IP-PBX system in which IP-PBXs are distributed and arranged on a plurality of geographically dispersed sites and combined on an IP network to operate as one large-scale system. Each node of the site includes an IP-PBX, a speech path switch, a line circuit that accommodates the legacy terminal group, a trunk circuit that accommodates the office line / dedicated line, and a call control processing device capable of controlling the intra-site connection. One center node monitors the operation of the entire system and monitors faults by loading station data to all remote nodes and managing them centrally, and the remote nodes operate cooperatively under the control of the center node. And

  Further, each IP-PBX has one unique processor number in the entire system, and the processor number is controlled and converted from the accommodation position that does not overlap in the entire system. .

  In addition, each of the remote nodes acquires station data from the center node via the IP network immediately after the power is turned on and starts operation, and the line circuit and the trunk circuit are commonly used in the system. Each remote node can start operating as a single system coupled on an IP network. The terminals accommodated in the center node and the remote node have the relationship of “extension of the same system”, and it is possible to construct a network with better service transparency than that of constructing a network with a common line.

  Further, the data setting of the remote node is also about the IP address information and processor number of the remote node necessary at the time of startup and the IP address information necessary to access the center node. Since the data uses the station data acquired from the center node via the IP network, the procedure for maintaining and operating the remote node is reduced, and the system capacity can be easily increased by adding the remote node. It is possible to expand.

  In addition, the center node and each remote node send and receive status monitoring signals via the IP network to check the connection, monitor the communication path on the IP network between the nodes, and determine whether communication to each node is possible. By grasping the state in advance, it is possible to suppress the occurrence of call loss due to communication failure. The center node notifies the state between the communication paths between the remote node and the remote node as an information element of the state monitoring signal from the center node to the remote node, thereby ensuring consistency of the node state and communication path state in the entire system. Can keep.

  If the remote node detects a failure or down of the center node as a result of transmission / reception of the status monitoring signal, or if a communication failure between the center node and the remote node is detected due to an IP network failure, the operation mode of the remote node is changed from cooperative operation. Change and start autonomous operation as a single system. As a result, it is possible to secure incoming and outgoing calls of the remote node, and it is possible to provide survival. Each remote node can automatically re-establish a connection with the center node when detecting a communication failure recovery between the center node and the remote node.

  In addition, the time for detecting a communication failure in the IP network can be arbitrarily set for each node according to the network bandwidth between the nodes, so that the remote node detects the failure and switches the remote node itself to autonomous operation. Can be shortened. Furthermore, when communication failure recovery between the center node and the remote node is detected, communication with the center node can be automatically re-established, so there is no need for the maintenance person to manually perform recovery work. The communication stop time between nodes can be minimized.

  Also, when the remote node starts autonomous operation, the failure information registration that the remote node has shifted to autonomous operation is registered in the remote node and the center node, and the maintenance person is notified that a network failure has occurred. Means can be provided. An indication that the autonomous node is operating is displayed on the extension terminal accommodated in the remote node that has shifted to autonomous operation, and the lamp of the extension terminal is lit / flashed to allow the remote node to operate autonomously. Means can be provided for notifying that the migration is in progress. While the remote node is autonomously operating, it is not possible to make or receive calls to the extension of other nodes, but it is possible to set an automatic detour operation to the public network by setting the station data. Incoming and outgoing calls can be continued, and the service function is not limited.

  In addition, when performing maintenance / fault monitoring of the entire system, station data setting and fault monitoring of a plurality of nodes can be performed from a single maintenance console. Station data can be set at the center node, and it is centrally managed at the center node as common information for each IP-PBX that constitutes the system, even though it is an IP-PBX system composed of multiple IP-PBXs. Is done. Each node has the same station data as the center node (acquired automatically at startup), and is distributed to each remote node every time station data is set from the maintenance console connected to the center node. When the remote node is operating cooperatively, the station data is automatically copied periodically from the center node to the remote node via the IP network.

  Also, billing information such as internal mutual billing / outgoing billing / incoming billing generated at each node, or fault information output when a fault occurs, is collected from each remote node to the center node so that maintenance is centrally managed. it can.

  Furthermore, in the IP terminal group, by setting the registration destination node as “belonging node”, it becomes possible to control the IP terminal group directly to the remote node, and communication with the center node is cut off. Even in this case, since the remote node can continue to use the exchange connection process, it is possible to construct a system that does not require the installation of the backup device at the remote site, so that the introduction cost of the backup device can be suppressed.

  As described above, according to the present invention, IP-PBXs are distributed and arranged at a plurality of geographically dispersed sites, and these IP-PBXs are combined on an IP network to form one large-scale IP-PBX system. Since each node that is constructed as a system and operates according to one station data that is centrally managed by the center node, the line circuit and the trunk circuit accommodated in each node can be used in common in the system. The first effect can be obtained.

  Also, because it is a single system, maintenance for each remote node is not required, and when a failure occurs in the communication path between the center node or the center node and the remote node, the remote node operates autonomously, and a backup device for the IP terminal group By pretending to be, the maintenance cost and introduction cost of the backup device can be reduced, and the telephone call between the legacy terminal group and the IP terminal group accommodated in the remote node can be secured, and it is also provided during autonomous operation. The service function is not limited, and in addition, there is no extra device in constructing the distributed IP-PBX system, and a sufficient redundant configuration can be provided, so that the highly reliable independent cooperative distributed IP-PBX system 2nd effect that can be provided can be acquired.

  Next, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

(1) System Configuration FIG. 1 is a diagram showing an embodiment of a distributed IP-PBX system according to the present invention. In this distributed IP-PBX system, IP-PBXs are distributed and arranged at three geographically separated sites A, B, and C, and one large-scale IP-PBX system is configured on the IP network 20. The IP-PBX 1a installed at the site A is connected to the IP network 20 via a PSTN (Public Switched Telephony Network) 2a and the router 3a, and includes a legacy terminal group 4a, an IP terminal group 5a, a maintenance console 6a, and a charging device 7a. And the center node 30 is configured. The IP-PBXs 1b and 1c installed at the sites B and C are connected to the IP network 20 via the PSTNs 2b and 2c and the routers 3b and 3c, respectively, and accommodate the legacy terminal groups 4b and 4c and the IP terminal groups 5b and 5c. Remote nodes 40 and 50 are configured.

  FIG. 2 shows a functional configuration of the center node 30 and the remote node 40 shown in FIG. In FIG. 2, a center node 30 controls at least one or more extension terminals H1, a line circuit H2 that controls the extension, a call control unit H3 that controls call processing, and switching in the nodes of each node. SW control unit H4, processor transfer control unit H5 that controls transfer inside and outside the processor, communication control unit H8 that connects to the IP network, main controller H9, trunk circuit H10 that connects to the PSTN, and IP network 20 has an IP line circuit H11 for connection to the station 20, and a station data file H12. The processor transfer control unit H5 includes a processor number conversion unit H6 that converts the accommodation position information into the processor number and an IP address conversion unit H7 that converts the processor number into the IP address of the node.

  The remote node 40 includes at least one extension terminal J1, a line circuit J2 that controls the extension, a call control unit J3 that controls call processing, and a SW control unit J4 that controls switching in the nodes of each node. And a processor transfer control unit J5 that controls transfer inside and outside the processor, a communication control unit J8 that connects to the IP network, a main control device J9, a trunk circuit J10 that connects to the PSTN, and a connection to the IP network 20 IP line circuit J11 and a station data file J12. The processor transfer control unit J5 includes a processor number conversion unit J6 that converts the accommodation position information into the processor number and an IP address conversion unit J7 that converts the processor number into the IP address of the node.

  Next, inter-processor communication between nodes according to the present invention will be described with reference to FIG. 2, FIG. 3, and FIG.

  Each node constituting this distributed IP-PBX system has a unique processor number in the system. The line circuit, trunk circuit, etc. accommodated in each node are assigned accommodation positions indicating all physical mounting positions. The accommodation position information is the accommodation position corresponding to the processor number, and the accommodation positions do not overlap in the system. The processor number conversion units H6 and J6 are circuits that perform conversion from the accommodation position to the processor number, and hold the table shown in FIG.

  In addition, since each node constituting this IP-PBX system operates with one station data, accommodation position information such as lines / trunks, extension number information, and other various service function control accommodated by other nodes. Necessary information can be recognized through the station data.

  Here, consider a case where the extension H1 accommodated in the center node 30 makes an extension call to the extension J1 accommodated in the remote node 40. The line circuit unit H2 of the center node 30 analyzes the number dialed by the calling extension H1, and obtains the accommodation position information of the called extension J1 from the station data. The processor number conversion unit H6 refers to the table of FIG. 3 and converts the accommodation position information into the processor number. When the obtained processor number is compared with the processor number of the own node, the called extension J1 becomes the remote node 40. Turned out to be contained in Next, the IP address conversion unit H7 refers to the table of FIG. 4 and derives the IP address of the remote node 40 from the processor number of the remote node 40 that is the destination. The processor transfer control unit H5 transfers information to the communication control unit H8 of the center node 30 to transmit the call signal to the remote node 40 that is the transfer destination, and the call control signal is transmitted to the IP network.

  On the remote node 40 side that accommodates the incoming call extension, when the communication control unit J8 receives a call control signal from the center node 30, it transfers the call control signal to the processor transfer control unit J5. The processor transfer control unit J5 recognizes in the processor number conversion unit J6 in the same control unit that the call signal is addressed to its own node.

  The embodiment of the inter-processor transfer of the distributed IP-PBX system according to the present invention has been described above. Switching in each node is performed by a known means. Since the switching system is a well-known technique and is well known to those skilled in the art, the detailed description is omitted, but the control signal is transmitted via the IP network, but the voice signal uses the trunk interface system. Alternatively, a peer-to-peer interface method using an IP line circuit may be used.

(2) Concept of the Invention The present distributed IP-PBX system cooperates as a single large-scale IP-PBX system by connecting IP-PBX systems distributed at a plurality of geographically separated sites on an IP network. The remote node itself operates autonomously so as to serve as a backup device at the remote site. For this purpose, the line circuit and the trunk circuit accommodated in the remote nodes 40 and 50 are commonly used in the system by using the station data that is centrally managed by the center node. First, the initial setting of the station data of the center node 30 and the remote node 40 will be described with reference to FIG.

  For the center node 30, the IP address 192.168.0.30 of the center node itself and the IP address information of the remote node are set for each processor number of the remote node constituting the system. For example, as the information of the remote node 40, the processor number 40 and the IP address 192.168.2.40 are registered in the station data at the maintenance console 6a. On the other hand, after starting the node, the remote node 40 has its own processor number 40, its own IP address information 192.168.2.40, and IP address information 192.168.8.0 for accessing the center node 30. .30 is registered at the maintenance console 6a and the station data is backed up in the remote node 40. By registering the data in the center node 30 and the remote node 40, communication between nodes becomes possible.

  Also, the initially set station data is updated in a timely manner. That is, the IP address of the IP terminal is distributed to all the nodes by broadcast transmission periodically or when the IP terminal is newly registered with each accommodating node. Thereby, the latest IP addresses of all the IP terminals accommodated in each node can be shared by all the nodes.

  Next, cooperative operation and autonomous operation will be described. The cooperative operation means that remote nodes distributed at remote sites operate as one large-scale IP-PBX system under the control of the center node. In this operation, the remote node can enjoy the network service with other remote nodes and the center node by the same operation as the service within the local station.

  Autonomous operation, on the other hand, means that the remote node cannot communicate with the center node due to an IP network failure, etc., and even if the control from the center node is lost, It means to operate with a single node. In this operation, communication between extension lines with the center node and other remote nodes is not possible, but outgoing and incoming calls outside the remote can be bypassed to the public network.

(3) Transition to Initial Cooperative Operation FIG. 6 shows a sequence of cooperative operation transition of the remote node. When the center node 30 is in a normal operation state (A1 in FIG. 6), when the power of the remote node 40 is turned on (B1 in FIG. 6), the remote node 40 loads the station data after starting up itself (B2). An initial setting request signal is transmitted to the terminal 30 via the IP network 20 (B3).

  The center node 30 that has received the initial setting request signal returns an initial setting request response signal indicating that the initial setting request signal has been received to the remote node 40 (A2). The remote node 40 that has received the initial setting request response signal next acquires the station data from the center node 30 and first stores the station data held by itself and the master station data held by the center node. In order to confirm whether or not there is a difference, a station data verification request signal is transmitted to the center node 30 (B4).

  The center node 30 that has received the station data verification request signal executes a checksum on its own station data (A3), and returns the checksum result to the remote node 40 on the station data verification request response signal (A4). ). The remote node 40 that has received the station data collation request response signal executes a checksum on its own station data (B5), and collates the checksum of its own station data with the checksum received from the center node (B6). ) If there is a difference in the station data (No in B7), a station data information transmission request signal is transmitted to the center node 30 (B8).

  Upon receiving the station data information transmission request signal, the center node 30 places the file number information (for example, the number of files 10) of the station data held by the center node 30 on the station data information transmission request response signal and returns it to the remote node 40. (A5). The remote node 40 that has received the station data information transmission request response signal transmits the station data transmission request signal 1 for requesting the station data file 1 to the center node 30 (B9). The center node 30 that has received the station data transmission request signal 1 transmits the station data file 1 on the station data transmission request response signal 1 to the remote node 40 (A6). The remote node 40 that has received the station data file 1 from the center node 30 then transmits a station data transmission request signal 2 for requesting the station data file 2 to the center node 30 (B10). In response to the request from the remote node 40, the center node 30 that has received the station data transmission request signal 2 places the station data file 2 on the station data transmission request response signal 2 and transfers it to the remote node 40 (A7).

  The remote node 40 repeats the exchange in the same procedure as B9 to A7 until the reception of the station data file of the file number information which is the information element of the station data information transmission request response signal is completed. Data is acquired (B12). When the reception of all the station data from the center node 30 is completed, the remote node 40 transmits to the center node 30 that the copy of the station data has been completed in a station data copy completion notification signal (B13).

  Further, the remote node 40 performs its own system initial in order to reflect the station data transmitted from the center node 30 on its own RAM (B14). When the system initialization is completed, the remote node 40 transmits an initial setting completion notification signal to the center node 30 in order to notify the center node that its initial setting is completed (B15). The center node 30 that has received the initial setting completion notification signal from the remote node 40 (A9) is already in the cooperative operation state in response to the cooperative operation start instruction signal that requests the remote node 40 to start the cooperative operation. Information on other remote nodes is loaded and transmitted to the remote node 40 (A10).

  The remote node 40 that has received the cooperative operation start instruction signal starts operation under the control of the center node 30 and enables inter-processor communication between the center node 30 and the remote node 40. In addition, the remote node 40 is one of the information elements of the cooperative operation start instruction signal received from the center node 30, and the remote node that is in the cooperative operation state based on the processor number information of another remote node that is already in the cooperative operation state. Communication between processors (for example, the remote node 50) becomes possible (B15).

  Further, the remote node 40 can obtain the IP address information from the processor number of another remote node in a cooperative state by reading the station data copied from the center node 30. In addition, the remote node 40 received from the center node 30 so that the station data received from the center node 30 can be operated by a single node even when the remote node 40 is restarted due to power-on again. Back up station data. In addition, the IP address information of the remote node 40 set first and the IP address information of the center node 30 are overwritten by the station data received from the center node 30, but the remote that configures the system in advance at the center node 30. There is no problem because it is station data in which the IP address information of the remote node is set for each processor number of the node.

(4) Transition of cooperative operation and autonomous operation (4.1) Condition of transition Next, state transition of the cooperative operation and autonomous operation of a remote node will be described with reference to FIG. The condition C1 for transitioning from the autonomous operation state to the cooperative operation state is when the initial setting request processing is completed after powering on the remote node or after detecting a failure by transmitting / receiving a state monitoring signal. The condition C2 for transitioning from the cooperative operation state to the autonomous operation state is when communication of the state monitoring signal with the center node is interrupted for a certain time during the cooperative operation.

  In addition, the condition that the remote node in the autonomous operation state continues the autonomous operation state is that the remote node cannot connect to the center node at the time of system reset due to power-on etc. (including the case where the connection is not permitted). ).

  As described above, if the remote node has acquired the station data from the center node, if the remote node cannot be connected to the center node, the remote node will be described in detail. If the remote node cannot be connected, the remote node operates autonomously as a single system, and calls can be made and received within the remote node range.

(4.2) Outline of the state monitoring operation between the center node and the remote Hereinafter, the outline of the state monitoring operation between the center node and the remote for detecting a failure related to the state transition condition of the cooperative operation and the autonomous operation will be described first.

  Each remote node transmits and receives a state monitoring signal between the center node and the remote node until the control of the center node is removed from the transition to the cooperative operation state. Note that the state monitoring signal is not transmitted to or received from the remote node in the autonomous operation state. The transmission / reception interval of the state monitoring signal can be set arbitrarily. The state monitoring signal is transmitted and received again after an arbitrarily set transmission and reception interval. The transmission / reception result of the state monitoring signal between the center node and the remote node is held in the state monitoring table of each node. The state monitoring signal transmitted from the center node to the remote node includes the processor number of the remote node that is performing the cooperative operation, and each remote node that has received it receives the state monitoring table stored in the remote node. The processor state table is updated, and the processor information of the remote node that is performing the cooperative operation can be made consistent among all the nodes.

  In the center node and each remote node, if there is no response to the state monitoring signal, a state abnormality is detected. If the response of the status monitoring signal is not returned within the specified time, the center node makes the inter-processor communication enable / disable status table of the status monitoring table for the remote node abnormal, and thereafter temporarily transfers the processor to the remote node. Is impossible.

  On the other hand, the remote node side makes the inter-processor communication enable / disable state table in the state monitoring table for the center node abnormal, and thereafter temporarily disables inter-processor transfer to the center node. After that, if no status monitoring signal is returned within the specified time, the center node makes the processor status table of the status monitoring table for the remote node abnormal, and thereafter stops sending the status monitoring signal to the remote node. .

  On the other hand, on the remote node side, the processor status table of the status monitoring table for the center node and the inter-processor communication enable / disable status table of the status monitoring table for other remote nodes are regarded as abnormal and shift to autonomous operation. Also, the transmission of the status monitoring signal to the center node and other remote nodes is stopped. The remote node that has shifted to the autonomous operation is repeatedly subjected to the initial setting request signal transmission process, and transmission / reception of the state monitoring signal is resumed after shifting to the cooperative operation.

(4.3) Details of Status Monitoring Operation Between Center Node and Remote Node An operation sequence for status monitoring between the center node 30 and the remote node 40 will be described with reference to FIGS. The same applies to transmission / reception of the state monitoring signal between the center node 30 and other remote nodes.

  The center node 30 in the operational state (D1 in FIG. 8) sets a reception wait timer for the state monitoring response signal, and sends a state monitoring signal (D2) to the remote node 40 in the cooperative state (E1 in FIG. 8). Send. When receiving the state monitoring signal from the center node 30, the remote node 40 returns a state monitoring response signal to the center node 30 (E2). When the center node 30 receives the state monitoring response signal from the remote node 40 before the expiration of the state monitoring response signal reception waiting timer, the center node 30 clears the state monitoring response signal reception waiting timer and sets the state monitoring table for the remote node 40 in the state monitoring table. The processor state table is set to a normal state, and a state monitoring re-response signal is returned to the remote node 40 (D3). When the remote node 40 receives the state monitoring re-response signal from the center node 30 before expiration of the state monitoring re-response signal reception waiting timer, the remote node 40 clears the state monitoring re-response signal reception waiting timer and sets the state for the center node 30. Set the monitoring table to normal status and set the status monitoring signal reception waiting timer.

  However, when a failure occurs in the IP network between the center node 30 and the remote node 40 and the state monitoring signal transmitted from the center node 30 does not reach the remote node 40 (D4), or from the center node 30 When the transmitted state monitoring signal reaches the remote node 40, but the state monitoring response signal returned from the remote node 40 to the center node 30 does not reach the center node 30 (E3), in the center node 30, Attempts to retransmit the state monitoring signal at a preset time / number of times (D4). If the state monitoring response signal is not replied within the set time, it is detected that the response to the remote node 40 is not more than an arbitrary number of times, a communication failure detection (temporary) is detected (D5), and the remote node 40 The inter-processor communication availability state table of the state monitoring table is set to an abnormal state, and transmission of control signals other than transmission / reception of state monitoring signals is stopped.

  It should be noted that the time and number of times of trying the above retransmission (D4) may be variably set according to the network bandwidth. Thereby, communication failure detection according to the network band can be performed.

  While the center node 30 is detecting a communication failure detection (temporary) for the remote node 40, the center node 30 tries again to transmit / receive the state monitoring signal for a preset time / number of times (D6, D7), but within the set time / number of times. If a response signal cannot be received, communication failure detection (fixed) is detected (D8), the processor status table of the status monitoring table of the remote node 40 is set to an abnormal status, and transmission of status monitoring signals thereafter is stopped. To do.

  On the other hand, the remote node 40 detects a communication failure detection (temporary) when the next state monitoring signal cannot be received from the center node 30 within a specified time from the state monitoring re-response signal last received from the center node 30. At the same time (E4), the inter-processor communication enable / disable state table of the state monitoring table for the center node 30 is set to an abnormal state, and transmission of control signals other than transmission / reception of state monitoring signals is stopped.

  The remote node 40 waits for reception of a state monitoring signal from the center node 30 for a predetermined time set in advance, but detects a communication failure detection (fixed) when a response signal cannot be received at the set time (E7). In addition, the processor status table of the status monitoring table of the remote node 40 is set to “abnormal”, and thereafter, the operation shifts to an autonomous operation (E8). At this time, the extension terminal J1 (FIG. 2) accommodated in the remote node 40 that has shifted to the autonomous operation is displayed on the extension terminal J1 indicating that the autonomous operation is in progress, and the lamp of the extension terminal J1 is lit / flashed. Alternatively, the remote node 40 may be notified that it is operating autonomously.

  During the autonomous operation, the remote node 40 continues to repeatedly transmit the initial setting request signal (B3 in FIG. 6) to the center node 30 until it shifts to the cooperation mode again. In addition, although it is not possible to make and receive calls to other nodes, it is possible to set an automatic detour operation to the PSTN via, for example, the trunk circuit J0 (FIG. 2) by setting the station data, so that the center node 30 can be connected even during the automatic operation. You can also continue to make and receive calls.

(4.4) Overview of Status Monitoring Operation Between Remote Nodes Each remote node transmits and receives status monitoring signals to and from other remote nodes from the time when it enters the cooperative state until it is out of control of the center node. The transmission / reception interval of each state monitoring signal can be arbitrarily set. The state monitoring signal is transmitted and received again after an arbitrarily set transmission / reception interval.

  When a specific remote node starts cooperative operation, the processor status of each node of the entire system notified by the status monitoring signal with the center node is reflected in the processor status table managed by the own node, and the remote node-remote Start transmission / reception of status monitoring signals between nodes. In the state monitoring between the remote node and the remote node, when the response signal cannot be received within the specified timer for the state monitoring signal transmission, the state monitoring signal is retransmitted as a temporary failure. If a response signal cannot be received within the specified timer even with respect to the retransmitted status monitoring signal, an error is detected, the processor transfer status of the status monitoring target is abnormal, and the inter-processor transfer to the remote node is stopped. While the inter-processor transfer is stopped, if the status monitoring signal is continuously transmitted and if the status monitoring response signal is received from the remote node within the specified number of times, the processor transfer status is normal and Resume interprocessor transfer.

(4.5) Details of Status Monitoring Operation Between Remote Nodes An operation sequence for status monitoring between the remote node and the remote node will be described between the remote node 40 and the remote node 50 with reference to FIG.

  The remote node 40 that has a young processor number and is in a cooperative state (F1 in FIG. 10) sets a timer for waiting for reception of a state monitoring response signal, has an old processor number, and is in a cooperative state (FIG. 10). G1) A state monitoring signal is transmitted to the remote node 50 (F2). When the remote node 50 receives the state monitoring signal from the remote node 40, the remote node 50 sets a reception wait timer for the state monitoring re-response signal, and returns the state monitoring response signal to the remote node 40 (G2).

  When the remote node 40 receives the state monitoring response signal from the remote node 50 before the expiration of the state monitoring response signal reception waiting timer, the remote node 40 clears the state monitoring response signal reception waiting timer and sets the state monitoring table for the remote node 50. Is set to a normal state, and a state monitoring re-response signal is returned to the remote node 50 (F3). When the remote node 50 receives the state monitoring re-response signal from the remote node 40 before the expiration of the state monitoring re-response signal reception timer, the remote node 50 clears the state monitoring re-response signal reception timer and sets the state for the remote node 40. Set the monitoring table to normal status and set the status monitoring signal reception waiting timer.

  However, when a failure occurs in the IP network between the remote node 40 and the remote node 50 and the state monitoring signal transmitted from the remote node 40 does not reach the remote node 50 (F4), or from the remote node 40 When the transmitted state monitoring signal reaches the remote node 50, but the state monitoring response signal returned from the remote node 50 to the remote node 40 does not reach the remote node 40 (G3), in the remote node 40, Attempts to retransmit the state monitoring signal for a preset time and number of times. If the status monitoring response signal is not returned within the set time, it is detected that the response to the remote node 50 is not more than an arbitrary number of times, a communication failure detection (temporary) is detected (F5), and the remote node 50 The inter-processor communication availability state table of the state monitoring table is set to an abnormal state, and transmission of control signals other than transmission / reception of state monitoring signals is stopped.

  It should be noted that the time and number of times for the above retransmission may be variably set according to the network bandwidth. Thereby, communication failure detection according to the network band can be performed.

  On the other hand, the remote node 50 detects a communication failure detection (temporary) when the next state monitoring signal cannot be received from the remote node 40 within a specified time from the state monitoring re-response signal last received from the remote node 40. (G4), the inter-processor communication enable / disable state table of the state monitoring table of the remote node 40 is set to an abnormal state, and transmission of control signals other than transmission / reception of the state monitoring signal is stopped.

  Although FIG. 10 shows the transmission / reception of the state monitoring signal between the remote node 40 and the remote node 50, the same applies to the transmission / reception of the state monitoring signal between other remote nodes.

  As described above, the communication path on the IP network is monitored in advance by sending and receiving state monitoring signals between the center node and the remote node, and between the remote node and the remote node, so that the communication availability status of each node is grasped in advance. Therefore, it is possible to suppress occurrence of call loss due to transfer failure between processors.

  In addition, the time until the remote node detects a failure and switches to autonomous operation can be shortened. Further, when communication failure recovery between the center node and the remote node is detected, communication with the center node is automatically performed. Can be established. For this reason, it is not necessary for the maintenance person to manually perform the recovery work, the time until the recovery can be shortened, and the communication stop time between the nodes can be minimized.

  In addition, since each IP terminal is directly accommodated in the node to which it belongs, even if a communication failure occurs between the center node and the remote node due to an IP network failure or the like, the accommodated remote node can be used instead of the backup device. Therefore, it can be used continuously.

The figure which shows one Embodiment of the distributed IP-PBX system which concerns on this invention The figure which shows the function structure of the center node and remote node which were shown in FIG. The figure which shows the content of the table which a processor number conversion part has The figure which shows the content of the table which an IP address conversion part has Sequence diagram of initial setting of station data to center node and remote node Sequence diagram for transition of cooperative operation of remote nodes Diagram for explaining state transition of remote node cooperative operation and autonomous operation Operation sequence diagram for status monitoring between the center node and the remote node The figure which shows the state monitoring table which each node has Operation sequence diagram for status monitoring between remote nodes

Explanation of symbols

A, B, C Site 10, 20 IP network 30 Center node 40, 50 Remote node 1a, 1b, 1c IP-PBX
2a, 2b, 2c PSTN
3a, 3b, 3c Router 4a, 4b, 4c Legacy terminal group 5a, 5b, 5c IP terminal group 6a Maintenance console 7a Billing device H1, J1 Extension terminal H2, J2 Line circuit H3, J3 Call control unit H4, J4 SW control unit H5, J5 Processor transfer controller H6, J6 Processor number converter H7, J7 IP address converter H8, J8 Communication controller H9, J9 Main controller H10, J10 Trunk circuit H11, J11 IP line circuit H12, J12 Station data

Claims (9)

In a distributed IP-PBX system in which IP-PBXs are distributed and distributed over a plurality of geographically dispersed sites and combined on an IP network to operate as one large-scale system,
Each node of the site includes a call control processing device capable of controlling intra-site connection, a line circuit accommodating the IP-PBX, a speech path switch, a legacy terminal group, a trunk circuit accommodating a station line / dedicated line,
One center node performs operation monitoring and failure monitoring of the entire system by loading station data to all remote nodes and managing them centrally.
The distributed IP-PBX system, wherein the remote node operates cooperatively under the control of the center node.   Each of the IP-PBXs has one processor number unique to the entire system, and the processor number is controlled and converted from the accommodation position without overlapping in the entire system. Item 4. The distributed IP-PBX system according to item 1.   Each of the remote nodes starts operation by acquiring the station data from the center node via the IP network immediately after power-on, and the line circuit and the trunk circuit are commonly used in the system. The distributed IP-PBX system according to claim 1 or 2.   4. The data setting of the remote node is IP address information and processor number of the remote node required at the time of startup, and IP address information necessary for accessing the center node. Distributed IP-PBX system. The center node and each remote node send and receive a state monitoring signal via the IP network to monitor a communication path on the IP network between the nodes,
As a result of the transmission / reception of the state monitoring signal, when the remote node detects a failure or down of the center node, or detects a communication failure between the center node and the remote node due to the IP network failure, the remote node changes its own operation mode. Change from the cooperative operation, start autonomous operation as a single system, and each remote node automatically re-establishes connection with the center node when it detects a communication failure recovery between the center node and the remote node The distributed IP-PBX system according to claim 4, which can be performed.   6. The distributed IP-PBX system according to claim 5, wherein a time for detecting a communication failure in the IP network can be arbitrarily set for each node in accordance with a network bandwidth between the nodes.   When the remote node starts the autonomous operation, the failure information registration that the remote node has shifted to the autonomous operation is registered in the remote node and the center node, and the maintenance person is notified that a network failure has occurred. The distributed IP-PBX system according to claim 5 or 6,   8. The distributed IP-PBX system according to claim 5, wherein during the autonomous operation of the remote node, an automatic detour operation to a public network can be set by setting the station data.   The billing information such as extension mutual billing / outgoing billing / incoming billing generated at each node or fault information output when a fault occurs is collected from each remote node to the center node. The distributed IP-PBX system according to 1 to 8.

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