JP2006101352A - Distributed accommodation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically balance loads of a plurality of call control servers unbalanced by fault occurrence or the like after fault recovery. <P>SOLUTION: A distributed accommodation system of the present invention comprises: a plurality of IP telephone apparatuses to be accommodated; a plurality of call control servers for carrying out call control while accommodating one or more IP telephone apparatuses to be accommodated by indefinite connection established via an IP network; and a load balancer which determines a call control server of a destination to accommodate an IP telephone apparatus to be accommodated that issues a connection establishment request and establishes connection with that call control server so as to balance loads of the plurality of call control servers. Each of the IP telephone apparatuses to be accommodated includes a connection re-establishment executing means for executing processing to re-establish connection by cutting off the established connection intermittently and automatically. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a distributed accommodation system, and is particularly suitable when a call control server that performs call control is applied to a plurality of multi-system IP-PBX systems.

  As an IP-PBX system, there is a multi-system system including a plurality of call control servers (hereinafter referred to as CM servers) that accommodate IP telephone terminals corresponding to extension terminals. And accommodated in any CM server via a load balancer.

  Here, for the call control of the CM server for each extension IP telephone terminal, there are a method using an indefinite connection and a method using a connection for each call or for each message. In many cases, a method of performing call control using an indefinite connection is often used in order to enhance the extension function.

  By the way, in a multi-system using a load balancer, if a method of performing call control using an indefinite connection is adopted, it is possible to change the accommodation of an extension IP telephone terminal to another CM server due to a failure of the CM server. can do. In this case, the load on the faulty CM server is shifted to another CM server.

  Conventionally, manual operation such as resetting the entire system has been required to restore the original load balance upon failure recovery.

  Therefore, there is a demand for a distributed accommodation system that can automatically balance the load of a plurality of call control servers that are unbalanced due to the occurrence of a failure after the failure is restored.

  In order to solve such a problem, a distributed accommodation system according to the present invention includes one or a plurality of accommodated IP telephone devices by a plurality of accommodated IP telephone devices and an indefinite connection established via an IP network. A plurality of call control servers that accommodate and execute call control, and a call control server that accommodates the accommodated IP telephone device that has issued a connection establishment request so that loads on the plurality of call control servers are equalized A load balancer that establishes a connection with the call control server, and an IP address assignment server that assigns an IP address in response to a request from each of the accommodated IP telephone devices. Intermittently and automatically disconnects established connections and reestablishes connections to reestablish connections Characterized in that it has a line unit.

  According to the distributed accommodation system of the present invention, even if the connection itself is normal, the connection re-establishment process is periodically executed. As a result, the load distribution among the plurality of call control servers is unbalanced due to some cause. Even in such a case, the load distribution can be shifted to an appropriate state by the re-establishment processing of each accommodated IP telephone device.

(A) First Embodiment Hereinafter, a first embodiment in which a distributed accommodation system according to the present invention is applied to an IP-PBX system having a multi-system configuration will be described with reference to the drawings.

(A-1) Configuration of the First Embodiment FIG. 1 is a block diagram showing a network configuration of the IP-PBX system 1 of the first embodiment. In FIG. 1, the IP-PBX system 1 of the first embodiment includes CM servers 10-1 to 10-N (N is an integer of 2 or more) that performs call control, and these CM servers 10-1 to 10-. A load balancer 11 that balances N loads, and an IP telephone terminal (hardware) as an extension terminal accommodated in any CM server 10-n (n is 1 to N) via the IP network 12 and the load balancer 11. TCP / IP network settings such as an IP address when the IP telephone terminal 13-m (m is 1 to M) is started, etc. And a DHCP server 14 for allocating information.

  Note that the IP telephone terminal is a concept that includes all terminals that communicate via an IP network. In addition, the load balancer 11 may be constructed as a dedicated device, or may be installed in any CM server. The CM servers 10-1 to 10-N and the load balancer 11 can be seen as one IP-PBX server from the IP telephone terminal 13-m. The CM servers 10-1 to 10-N and the load balancer 11 are the same as the existing ones.

  FIG. 2 is a block diagram showing an example of the internal configuration of the IP telephone terminal 13-m. In FIG. 2, the IP telephone terminal 13-m includes a microphone 20, a speaker 21, a codec unit 22, a control / VOIP processing unit 23, an IP line interface unit 24, an operation panel unit 25, a memory unit 26, and the like.

  The microphone 20 (transmitter) captures the user's voice, and the speaker (receiver) 21 generates and outputs control sounds such as voice and PB sound to the user. For example, an off-hook switch is provided in connection with the handset (20 and 21).

  The codec unit 22 converts the call signal from the microphone 20 into a digital signal and gives it to the control / VOIP processing unit 23, or converts the digital call signal from the control / VOIP processing unit 23 into an analog signal and gives it to the speaker 21. It is something to do. The codec unit 22 is mainly responsible for A / D conversion and D / A conversion, and the control / VOIP processing unit 23 performs encoding before IP packet assembly and decoding after IP packet decomposition. It shall be.

  The control / VOIP processing unit 23 is composed of, for example, a one-chip processor on which a CPU and a DSP are mounted. The control / VOIP processing unit 23 follows the program, fixed data, and registration data stored in the memory unit 26, and the memory unit 26 is used as a working memory. As a result, the overall operation of the IP telephone terminal 13-m is controlled, and VOIP processing such as assembly and disassembly of IP packets is performed.

  The IP line interface unit 24 performs an interface with the IP network 12.

  The operation panel unit 25 includes a key for taking in a telephone number and the like, and a display for displaying a destination number, and implements a man-machine interface under the control of the control / VOIP processing unit 23.

  The memory unit 26 stores programs, fixed data, registration data, and the like necessary when the control / VOIP processing unit 23 executes processing, and is also used as a working memory when the control / VOIP processing unit 23 performs processing. It is what is done.

  In the case of the first embodiment, the memory unit 26 stores the IP address reacquisition program 26a and the TCP / IP network setting information shown in FIG. 5, and the allocation included in the TCP / IP network setting information. The IP address reacquisition program 26a is started when the deadline (rebounding period elapses) 26b is reached.

  FIG. 3 is a block diagram illustrating an internal configuration example of the DHCP server 14. The DHCP server 14 includes, for example, a CPU 30, a memory 31, a program storage unit 32, a data storage unit 33, and an IP line interface unit 34, and these components are connected via a server internal bus 35. The IP line interface unit 34 performs an interface with the IP network 12.

  Note that the network used for communication between the IP telephone terminal 13-m and the DHCP server 14 is not limited to the IP network 12.

  In the DHCP server 14, for example, a program or data relating to the processing requested at that time is appropriately extracted from the program storage unit 32 (for example, HDD) or the data storage unit 33 (for example, HDD) and set in the memory 31. Then, the CPU 30 executes the program set in the memory 31 so as to provide the functions required for the DHCP server 14.

  In the case of the first embodiment, the program storage unit 32 stores the IP address allocation program 32a shown in FIG. 4, and the data storage unit 33 stores the latest allocation time limit data 33a and the allocatable IP address. Group (data) 33b, an IP address 33c on the server side that accommodates the IP telephone terminal 13-m, and the like. Note that the assignable IP address group (data) 33b is accompanied by attribute information such as not only the IP address but also whether or not it is assigned and the validity period of the assignment (allocation deadline).

(A-2) Operation of the First Embodiment Hereinafter, a characteristic operation in the IP-PBX system 1 of the first embodiment will be described. First, the operation when the IP telephone terminal 13-m first acquires its own IP address will be described.

  When the IP telephone terminal 13-m is newly installed and its power is turned on, the IP telephone terminal 13-m sends a request for assigning an IP address to itself to the DHCP server 14.

  Upon receiving such a request, the DHCP server 14 (the CPU 30 thereof) starts the IP address assignment program 32a shown in FIG. 4 (by setting it in the memory 31). First, from the assignable IP address group 33b, One IP address with unassigned attributes is taken out and determined as the IP address to be assigned this time (step 100). Thereafter, the DHCP server 14 (the CPU 30 thereof) retrieves the data 33a of the latest allocation deadline, and determines the expiration date of the IP address assigned this time by adding a predetermined time (for example, 30 minutes) to the deadline (step) 101).

  Then, the DHCP server 14 (the CPU 30) sets the “assigned” state as the attribute information of the IP address assigned this time in the assignable IP address group 33b, and the assignment deadline determined in step 101 Is added (note that information specifying the IP telephone terminal 13-m may also be added), and the latest allocation time limit data 33a is also updated to the one determined in step 101 (step 102).

  Thereafter, the DHCP server 14 (CPU 30 thereof) assembles TCP / IP network setting information to be returned to the requested IP telephone terminal 13-m (step 103), and the IP telephone terminal that has requested the TCP / IP network setting information. 13-m is returned to end the series of processing shown in FIG. 4 (step 104). The TCP / IP network setting information to be returned includes the IP address 33c on the server side, which is the IP address of the device on the side accommodating the IP telephone terminal 13-m, in addition to the assigned IP address and the assignment deadline. Yes. Furthermore, it may include other information necessary for executing communication.

  Although the flowchart and sequence diagram are omitted, the IP telephone terminal 13-m to which the TCP / IP network setting information as described above is returned stores the returned TCP / IP network setting information in the memory unit 26, and then the server. An indefinite connection (TCP connection) is established according to a well-known procedure with the counterpart device having the IP address 33c on the side to establish a connection (see FIG. 5).

  Note that a connection establishment message (IP packet) including the server-side IP address 33c reaches the load balancer 11, and the load balancer 11 loads the loads on the CM servers 10-1 to 10-N at that time. Considering this, the CM server 10-n that accommodates the IP telephone terminal 13-m to be used for establishing the connection is determined and the connection is established. Even if the connection is established, from the IP telephone terminal 13-m, the CM servers 10-1 to 10-N and the entire load balancer 11 appear as IP-PBX servers, and the CM servers actually accommodated are The changing IP phone terminal 13-m does not know.

  When establishing such a connection, a call is made by establishing a session.

  In each IP telephone terminal 13-m, the control / VOIP processing unit 23 activates a predetermined processing program at regular intervals based on the time measured by a timer (not shown).

  The control / VOIP processing unit 23 of each IP telephone terminal 13-m reacquires the IP address shown in FIG. 5 when the allocation time limit 26b included in the TCP / IP network setting information stored in the memory unit 26 is reached. The program 26a is activated.

  First, the control / VOIP processing unit 23 determines whether or not a call is currently being made (step 200). If the call is in progress, the IP address reacquisition program 26a shown in FIG. 5 is set to restart at a predetermined time (for example, 1 minute), and the series of processing shown in FIG. 6 is terminated (step 201).

  If the call is not currently in progress, the control / VOIP processing unit 23 executes a disconnection process with the accommodated (virtual) IP-PBX server side (step 202). Thereafter, a request for assigning the IP address to itself is transmitted to the DHCP server 14 (step 203), and the TCP / IP network setting information is awaited to be returned (step 204). The allocation request at this time may be the same as or different from the allocation request issued when the IP telephone terminal 13-m is powered on.

  Also in response to the allocation request at this time, the DHCP server 14 executes the IP address allocation program 32a shown in FIG. 4 and returns TCP / IP network setting information to the requesting IP telephone terminal 13-m.

  The IP telephone terminal 13-m stores the returned TCP / IP network setting information in the memory unit 26 (step 205), and then follows a well-known procedure with the counterpart apparatus having the server-side IP address 33c. Then, an indefinite connection (TCP connection) is established (step 206), and the series of processing shown in FIG.

  Next, although the flowchart is omitted, the scheduled processing in the DHCP server 14 (CPU 30 thereof) will be briefly described.

  One of the scheduled processes (programs) in the DHCP server 14 is an IP address allocation state restoration process.

  When the DHCP server 14 (the CPU 30 thereof) starts the return processing of the IP address assignment state, an IP address whose attribute is in the assignment state and whose current time exceeds the assignment deadline is included in the assignable IP address group 33b. If there is such an IP address, the attribute is changed to unallocated.

(A-3) Effect of First Embodiment According to the IP-PBX system having the multi-system configuration of the first embodiment, when a failure occurs in any CM server and it is recovered, it is automatically In addition, it is possible to return to an appropriate load distribution state to a plurality of CM servers.

  For example, as shown in FIG. 6A, there are two CM servers 10-1 and 10-2, and IP telephone terminals 13-1 and 13-2 are accommodated in the CM server 10-1. When a failure occurs in the CM server 10-1 in a state where the 13-3 and 13-4 are accommodated in the CM server 10-2, all the IPs as shown in FIG. The telephone terminals 13-1 to 13-4 are changed to a state accommodated in the CM server 10-2.

  Eventually, when the CM server 10-1 recovers from the failure, the load balancer 11 recognizes that fact.

  When the IP address allocation time limit is reached, the IP telephone terminal 13-1 disconnects the connection so far, receives an IP address reset from the DHCP server 14, and performs a connection establishment operation. At this point, the load balancer 11 has three IP telephone terminals 13-2 to 13-4 accommodated in the CM server 10-2, and the CM server 10-1 does not accommodate one IP telephone terminal. Therefore, the CM server 10-1 is determined to accommodate the IP telephone terminal 13-1 related to the current connection establishment.

  The load distribution to the plurality of CM servers is restored to an appropriate state by the connection resetting process executed by the IP telephone terminal 13-1 for each IP address allocation deadline as described above.

(B) Second Embodiment Next, a second embodiment in which the distributed accommodation system according to the present invention is applied to an IP-PBX system having a multi-system configuration will be described with reference to the drawings. The difference will be mainly described.

  In the first embodiment, only the IP telephone terminals 13-1 to 13-M are accommodated in the CM server 10-n. However, in the second embodiment, in addition to this, the remote unit 15-1 to 15-K are also accommodated (IP connection) in the CM server 10-n via the unit load balancer 16. The remote unit 15-k (k is 1 to K) accommodates a plurality of lines (up to 128 lines) of analog terminal interfaces and office line interfaces, and is IP-connected to the CM server 10-n. The “accommodated IP telephone device” in the claims includes not only the IP telephone terminal but also such a remote unit.

  Each CM server 10-n is load-balanced by a load balancer, but the IP telephone terminal 13-m and the remote unit 15-k are load-balanced by different virtual IP addresses.

  The remote unit 15-k also acquires the same information (assigned IP address and the like) as in the first embodiment from the DHCP server 14, but the IP telephone terminal 13-m and the remote unit 15-k acquire the connection. The IP address of the destination server is different (the load balancer to be connected is different between 11 and 16).

  Except for the above points, the second embodiment is the same as the first embodiment.

  In the IP-PBX system having the multi-system configuration of the second embodiment, the remote unit is also targeted as an element accommodated by the IP-PBX main body, but the same effect as that of the first embodiment can be obtained. it can. In other words, even if an IP telephone terminal and a remote unit having different loads per TCP connection are accommodated, when one of the CM servers fails and is recovered, a plurality of CM servers are automatically created. It is possible to return to an appropriate load distribution state.

(C) Other Embodiments In the above embodiments, the IP telephone terminal or remote unit re-acquires the IP address from the DHCP server and then reestablishes the connection with the CM server side. Without re-acquiring the address, after a predetermined period of time has elapsed since the previous connection was established, the connection may be temporarily disconnected and then re-established with the CM server side based on the initially acquired IP address. . That is, the connection may be disconnected and re-established regardless of the allocation time limit assigned by the DHCP server.

  In each of the above embodiments, the distributed accommodation system of the present invention is applied to an IP-PBX system having a multi-system configuration. However, in the switching system having the same configuration as the IP-PBX system having a multi-system configuration, The present invention can be applied.

It is a block diagram which shows the network structure of the IP-PBX system of 1st Embodiment. It is a block diagram which shows the internal structural example of the IP telephone terminal of 1st Embodiment. It is a block diagram which shows the internal structural example of the DHCP server of 1st Embodiment. It is a flowchart which shows the allocation process of the IP address in the DHCP server of 1st Embodiment. It is a flowchart which shows the re-establishment process of the connection in the IP telephone terminal of 1st Embodiment. It is explanatory drawing of the effect of 1st Embodiment. It is a block diagram which shows the network structure of the IP-PBX system of 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... IP-PBX system, 10-1-10-N ... CM server, 11, 16 ... Load balancer, 12 ... IP network, 13-1-13-M ... IP telephone terminal, 14 ... DHCP server, 15-1 ~ 15-K ... Remote unit.

Claims (5)

A plurality of accommodated IP telephone devices;
A plurality of call control servers for accommodating one or a plurality of the accommodated IP telephone devices and performing call control by an indefinite connection established via the IP network;
A load balancer for defining a destination call control server for the accommodated IP telephone device that has issued a connection establishment request so as to equalize the load on the plurality of call control servers and establishing a connection with the call control server; ,
An IP address assignment server for assigning an IP address in response to a request from each of the accommodated IP telephone devices,
Each of the accommodated IP telephone devices has connection re-establishment execution means for executing a process of disconnecting the established connection and re-establishing the connection intermittently and automatically.   2. The distributed accommodation system according to claim 1, wherein the connection re-establishment executing unit re-acquires an IP address from the IP address assignment server and executes re-establishment processing when re-establishing the connection. . When the IP address allocation server returns the IP address allocated in response to the request from the accommodated IP telephone device, the IP address allocation server replies with the expiration date information of the IP address,
The distributed accommodation system according to claim 2, wherein the connection re-establishment executing unit executes connection re-establishment processing at a timing when a time limit indicated by the expiration date information of the received IP address is exceeded. ｀
The connection re-establishment executing means executes connection re-establishment processing after waiting for the end of the call state if a call is in progress at the start timing of connection re-establishment processing. 4. The distributed accommodation system according to any one of 3 above. The load balancer includes a first load balancer and a second load balancer, and the first and second load balancers target different types of accommodated IP telephone devices having different loads per connection. Item 5. The distributed storage system according to any one of Items 1 to 4.

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