JP2010041088A - Terminal handover system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a terminal handover system and a method, which correctly hand over a terminal in one call agent to another call agent. <P>SOLUTION: The system has one or more first call control relay devices for accommodating a plurality of terminals each performing call control between terminals in communication; and a variable address setting means for giving a variable address of the call control relay device to a terminal. In the system, the first call control relay devices each give subscriber information of each subscription terminal to the second call control relay device of switching destination and hand over the subscriber terminal, a message transfer means converts a call control message addressed to each first call control relay device or each second call control relay device into a call control message addressed to each second call control relay device or each first call control arbitration device and transfers the converted call control message after the subscriber information is transferred, and the variable address setting means changes the variable address of the call control relay device assigned to each subscriber terminal from the address of the first call control relay device to that of the second call control relay device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a terminal accommodation switching system and method, and can be applied to, for example, a switching system and method for switching a call agent (CA) that accommodates a large number of VoIP (Voice Over IP) gateways.

  With the recent spread of VoIP communication systems, the use of VoIP is increasing, so that call agents that accommodate VoIP gateways need to be replaced with new call agents that have higher capacity and processing capacity.

  In that case, since real-time performance is required for voice communication, it is not desirable to interrupt a call during a call, and it is necessary to respond to a call start / end request during call agent exchange. .

  In addition, it is necessary to accurately transfer call information, subscriber information, and the like held by the call agent before exchange to a new call agent. Therefore, it is desirable to exchange call agents without stopping.

  Patent Document 1 describes a technique related to the exchange processing for the call agent as described above, which provides high communication quality and reliability and is an effective technique.

JP 2007-124231 A

  By the way, although it was not necessary in the conventional VoIP communication system, in recent years, for example, the number of VoIP gateways accommodated in the CA may exceed the CA subscriber accommodation capacity due to the increase in the number of subscribers. There is a problem of changing the accommodation of subscribers in the CA, such as accommodating the VoIP gateway in a CA having a larger subscriber accommodation capacity.

  As is well known, VoIP communication such as an IP phone is real-time communication, and each subscriber starts and ends VoIP communication at an arbitrary timing based on their own circumstances. It can be said that it is a service that needs to be provided by stopping. Therefore, for example, if the call control cannot be performed at the time of the accommodation change and the VoIP communication cannot be performed, it is recognized by a huge number of subscribers as a significant deterioration in communication quality (service quality) or communication reliability.

  The configuration of a VoIP communication system 10 using a DHCP server is as shown in FIGS. FIG. 11 shows a case where there is only one CA, and FIG. 12 shows a case where there are two CAs, CA 11 that will not accommodate the VoIP gateway 13 and CA 15 that will accommodate the VoIP gateway 13 due to the accommodation change. Show.

  In FIG. 12, in the VoIP communication system 10, since the VoIP gateway 13 has received the setting of the IP address of the CA 11 as the IP address of the call agent from the DHCP server 12 before the accommodation change, The server 12 changes the IP address (here, I11) of the CA set for each VoIP gateway (one is 13) to another IP address (here, I15).

  However, since the VoIP gateway 13 transmits a setting request to the DHCP server 12 when the power is turned on (started up) according to a normal DHCP procedure, the call that the DHCP server 12 sets in the VoIP gateway (for example, 13). The IP address of the agent is set to each VoIP gateway at the timing when this setting request is transmitted.

Since the power-on timing is different for each VoIP gateway, even if the IP address of the call agent is changed from I11 to I15 by setting in the DHCP server 12, the VoIP gateway cannot change the accommodation destination CA at the same time. For this reason, during the transition period from when a new call agent IP address is set to the first VoIP gateway to when a new call agent IP address is set to all VoIP gateways, outgoing and incoming calls between VoIP gateways are made. The possibility of not being able to be increased.

  As a method for solving this, the following methods (M1) and (M2) are conceivable.

  (M1) The DHCP lease time is set to an extremely short time (for example, about several minutes).

  (M2) Each VoIP gateway is restarted by remote operation via the network.

  However, in the method (M1), since the lease time currently set to about 24 hours becomes extremely short, the traffic of packets transmitted and received according to the DHCP procedure increases rapidly and consumes network bandwidth. An excessive load is applied to the processing capability of the DHCP server 12. Further, in order to change the lease time, it is necessary to change the setting for the DHCP server 12 a plurality of times.

  Usually, the environment in which the VoIP communication system 10 is constructed is a multi-vendor environment mainly including distributed control when including nodes of a transmission control level such as a router. In a large-scale system that is currently operated, It is difficult to accurately predict what kind of effect will occur when such a sudden increase in traffic, an increase in the load on the DHCP server, or multiple setting changes are performed, and unexpected problems may occur Is expensive.

  In addition, the method (M2) is to perform a remote operation and attempt to restart the VoIP gateway (for example, 13), but the state of the VoIP gateway at that time (for example, in a state where the power is turned off for a long time, It may not be possible to restart depending on whether it is left unattended, etc., and the remote operation is usually performed manually by a maintenance person or the like, so that the work load is large.

Even if all VoIP gateways can be restarted almost simultaneously, packet traffic sent and received in accordance with the DHCP procedure is generated almost simultaneously for all VoIP gateways. The problem of capacity load and traffic spikes are significant. Alternatively, when a large number of VoIP gateways that could not be restarted are generated, the problem of how to deal with them remains, and the feasibility is low.

  The present invention relates to the technology described in Patent Document 1 and provides high communication quality and reliability.

  In order to solve this problem, the terminal accommodation switching system according to the first aspect of the present invention mediates transfer of call control messages transmitted / received between a plurality of terminals that perform call control between opposite terminals and communicate with each other. A variable address setting means for assigning a call control mediating device and giving a variable address of the call control mediating device to the terminal, and one or a plurality of first receiving a plurality of terminals in response to the setting of the variable address setting means In a terminal accommodation switching system comprising a call control mediating device and accommodating each accommodating terminal accommodated in each first call control mediating device in one or a plurality of second call control mediating devices, (1) each first The call control intermediary device includes subscriber information transfer means for transferring the stored subscriber information of each accommodating terminal to the second call control intermediary device to be switched, and (2) the subscriber information After the relocation, each first call system A message transfer means for converting the call control message addressed to the mediation device or each second call control mediation device to the respective second call control mediation device or each first call control mediation device and transferring the message (3) The variable address setting means changes the variable address of the call control mediating device assigned to each accommodation terminal from the variable address of the first call control mediating device to the variable address of the second call control mediating device. And a variable address changing unit.

  The terminal accommodation switching method according to the second aspect of the present invention assigns a plurality of terminals that perform call control between opposite terminals and communicates, and a call control mediating apparatus that mediates exchange of call control messages transmitted and received between the terminals, A variable address setting means for giving a variable address of the call control intermediary device to the terminal, one or a plurality of first call control mediation apparatuses accommodating a plurality of terminals in response to the setting of the variable address setting means, and message transfer A terminal accommodation switching method in which each accommodation terminal accommodated in each first call control mediating device is accommodated in one or a plurality of second call control mediation devices. (1) Each first call control The intermediary device transfers the stored subscriber information of each accommodating terminal to the second call control intermediary device that is the switching destination, and (2) the message transfer means Addressed to the first call control mediation device The call control message addressed to each second call control mediating device is converted and transferred to each second call control mediating device or to each first call control mediating device, and (3) variable address setting means, The variable address of the call control mediating device assigned to each accommodating terminal is changed from the variable address of the first call control mediating device to the variable address of the second call control mediating device.

  According to the present invention, call control and subscriber information held by a call agent before switching can be accurately transferred, and call control can be correctly performed even during switching.

(A) 1st Embodiment Below, the 1st Embodiment of the terminal accommodation switching system and method of this invention is described in detail, referring drawings.

  The first embodiment exemplifies an embodiment when the present invention is applied to a switching system that exchanges a call agent in a VoIP communication system with another call agent.

(A-1) Configuration of the First Embodiment FIG. 2 is an overall configuration diagram showing the overall configuration of the first embodiment VoIP communication system.

  In FIG. 2, the VoIP communication system 20 includes an old call agent 22 to be exchanged, a new call agent 23, a forwarding device 24, a DHCP server 25, VoIP gateways 26 and 27, and general telephones 28 and 29 connected to a network 21. It is configured to have at least.

  Among these, the network 21 is a network in which the IP protocol is used in the network layer of the OSI reference model. An IP network or the like operated by a specific communication carrier may be used, or the Internet may be used. A number of routers (not shown) exist in the network 21 and relay IP packets at the network layer.

  The call agent 22 is a call agent to be exchanged. As a function related to the call control of the call agent 22, the subscriber information SD is held in the same manner as the function of the existing call agent, and the call control message relay processing between VoIP gateways and various controls necessary for VoIP communication. And manage.

  Here, the subscriber information SD includes the telephone numbers of the general telephones 28 and 29 of the users U1 and U2, the IP addresses of the VoIP gateways 26 and 27 that accommodate the general telephones 28 and 29, and these telephone numbers and IP addresses. This information also includes the correspondence relationship.

  The call agent 23 is a new call agent. As the function of the call agent 23, an existing one similar to the call agent 22 can be applied.

  The forwarding device 24 is a transfer device that converts a transmission destination IP address of a packet received from the network 21 into another IP address set in advance and transfers the packet.

  Further, the forwarding device 24 is installed in the call agent 22 to be exchanged before changing the IP address of the call agent in the DHCP server 25 from the IP address I22 of the call agent 22 to the IP address I23 of the call agent 23. . Then, the IP address of the packet addressed to the call agent 22 is converted into the IP address of the call agent 23 newly established by the forwarding device 24 and transferred.

  As a result, the forwarding device 24 can transfer the packet addressed to the call agent 22 to the call agent 23.

  Further, since the forwarding device 24 is installed in the call agent 22 to be exchanged before the setting of the IP address of the call agent in the DHCP server 25 is changed, the IP address of the call agent for the VoIP gateways 26 and 27 is set by the DHCP server 25. The packet can be transferred to the new call agent 23 before paying out (before re-acquiring the IP address).

  As the forwarding device 24, for example, a standard IP packet forwarding function such as UNIX (registered trademark) or Linux (registered trademark) or a physically independent IP packet forwarding device can be applied.

  In the first embodiment, a case where a physically independent IP forwarding device is used is illustrated.

  In response to a request from the DHCP client, the DHCP server 25 sends TCP / IP-related basic configuration information (for example, default gateway, DNS server IP address, communication device) to the communication device equipped with the DHCP client. The IP address to be assigned is set. In general, a DHCP client requests configuration information setting according to a DHCP procedure when the communication device is powered on and the OS of the communication device is started.

  The DHCP server 25 is not limited to VoIP communication and is widely used in TCP / IP networks, but the DHCP server 25 is different from the DHCP server used in a general TCP / IP network in that the IP address of the call agent is Is set.

  For example, when the IP address assigned to the call agent 22 is I22, when the call agent 22 is used by the VoIP gateways 26 and 27, the IP address I22 of the call agent 22 is set in the VoIP gateways 26 and 27.

  Here, the use refers to, for example, the VoIP gateways 26 and 27 causing the call agent 22 to relay a call control message. Further, since the network 21 is an IP network, the call control message is transmitted in a form accommodated in an IP packet.

  The VoIP gateways 26 and 27 are gateway devices having a call control function and a VoIP compatible function, and an existing VoIP gateway can be applied.

  The general telephones 28 and 29 are telephones used by the users U 1 and U 2. The general telephone 28 is accommodated in the VoIP gateway 26 and the general telephone 29 is accommodated in the VoIP gateway 27.

  The first embodiment exemplifies a case where the general telephones 28 and 29 do not have a VoIP compatible function, and the general telephones 28 and 29 are connected to the network 21 by being accommodated in the VoIP gateways 26 and 27. VoIP communication is realized.

  Further, I26 is an IP address of the VoIP gateway 26, and TN26 is a telephone number of a general telephone 28 accommodated therein. I27 is an IP address of the VoIP gateway 27, and TN27 is a telephone number of a general telephone 29 accommodated therein.

(A-2) Operation of the First Embodiment Next, the operation of the subscriber information accommodation device switching process in the VoIP communication system 20 of the first embodiment will be described with reference to the drawings.

  1 and 3 are explanatory diagrams for explaining the operation of switching processing of the subscriber information accommodation apparatus of the first embodiment.

  1 and 3 exemplify the case where the call agent 22 that accommodates the VoIP gateway 26 is replaced with a newly established call agent 23. FIG.

  Before switching the call agent, when the DHCP server 25 receives an acquisition request for an IP address of a call agent that can be used from the VoIP gateway 26 functioning as a DHCP client, the IP address I22 of the call agent 22 is assigned. Is provided to the VoIP gateway 26.

  At this time, the DHCP server 25 sets the IP address of the call agent 22 as configuration information to be set in the VoIP gateway 26, but also sets the lease time for the expiration date of the IP address.

  For example, the lease time of the expiration date for use of the IP address of the call agent 22 is set based on a predetermined rule, but for example, a lease time of 24 hours is set. When the expiration date of the lease time ends, the configuration information including the assignment of the IP address of the call agent 22 is reset.

  The VoIP gateway 26 acquires the IP address I22 of the call agent 22 from the DHCP server 25, and performs call control using the call agent 22.

  That is, in the state before the switching, the VoIP gateway 26 that performs call control uses the IP address I22 as the destination IP address of the call control message and transmits the call control message to the call agent 22 to perform call control.

  The call agent 22 holds subscriber data of the VoIP gateway 26 and performs call control based on a call control message from the VoIP gateway 26.

  Thereafter, the switching process from the call agent 22 to the new call agent 23 is performed according to the following procedure.

  First, the forwarding device 24 sets the packet received to the IP address I22 of the call agent 22 to be transferred to the IP address of the call agent 23, and sets it to the call agent 22 to be switched. At this time, a forwarding destination set by the forwarding device 24 is set, but the forwarding process is not executed.

  Next, all subscriber information held in the call agent 22 is moved (copied) to the newly established call agent 23 (step S10).

  When all the migration of the subscriber information is completed, the call agent 22 is disconnected from the network 21, and the forwarding device 24 is installed in the network 21 instead of the call agent 22 (step S11).

  At this time, in the DHCP server 25, the IP address of the call agent set in the VoIP gateway 26 is set to I22.

  Accordingly, the VoIP gateway 26 that has acquired the IP address I22 of the call agent 22 from the DHCP server 25 transmits a call control message addressed to the call agent 22 (step S12).

  The forwarding device 24 that has received the call control message from the VoIP gateway 26 converts the destination of the received call control message to the IP address I23 of the new call agent 23, and forwards the call control message to the call agent 23 (step). S13).

  The call control message forwarded by the forwarding device 24 is given to the call agent 23, and a response message to the call control message is returned to the VoIP gateway 26 by the call agent 23 to perform call control (step S14).

  Thereafter, the DHCP server 25 changes the IP address setting of the call agent 22 accommodating the migration target VoIP gateway 26 in FIG. 3 (step S15). That is, the IP address of the call agent assigned to the VoIP gateway 26 is changed from I22 to I23.

  Here, after the IP address setting of the call agent is changed in the DHCP server 25, the VoIP gateway 26 makes a request to the DHCP server 25 in accordance with the DHCP procedure (step S16). Since resetting (including resetting of the IP address of the call agent) is performed, the VoIP gateway 26 that has performed the DHCP access sequentially transmits call control messages to the newly established call agent 23 (step S17). The new call agent 23 that has received the call control message returns a response message to the VoIP gateway 26 to perform call control.

  In this way, it waits for re-acquisition of configuration information from the DHCP server 25 for all VoIP gateways accommodated by the call agent 22.

  When the reacquisition of the configuration information of all the VoIP gateways to be migrated is completed and the call control messages of all the VoIP gateways are transmitted and received only by the call agent 23, the forwarding device 24 is disconnected from the network 21 (step S18).

(A-3) Effect of the First Embodiment As described above, when the call agent subscriber accommodation is changed, the call is made and received during the time depending on the lease time of the configuration information in the DHCP server. However, according to the procedure described in the first embodiment, the use of a forwarding device can absorb the time lag of DHCP reacquisition that occurs for each VoIP gateway. Time during which incoming calls cannot be made can be eliminated.

(B) 2nd Embodiment Next, 2nd Embodiment of the terminal accommodation switching system and method of this invention is described in detail, referring drawings.

  The second embodiment also exemplifies an embodiment when the present invention is applied to a switching system in which a call agent in a VoIP communication system is exchanged with another call agent.

(B-1) Configuration and operation of the second embodiment The second embodiment differs from the first embodiment in the processing procedure for changing the subscriber accommodation of a call agent.

  The configuration of the second embodiment uses a forwarding function provided as a standard in UNIX (registered trademark), Linux (registered trademark), and the like, which is provided in a newly established call agent.

  Therefore, although the forwarding device 24 shown in FIG. 2 is not used, the other configuration is the same as that of the first embodiment, and therefore, the second embodiment will be described with reference to FIG.

  The new call agent 23 is a call agent having a call control function, as in the first embodiment. Further, as described above, the call agent 23 includes the forwarding function unit 23a provided as standard in UNIX (registered trademark) or the like.

  Similar to the forwarding device 24 described in the first embodiment, the forwarding function unit 23a converts the destination address of the received packet into a predetermined IP address and transfers it.

  4 and 5 are explanatory diagrams for explaining the operation of the switching process of the subscriber information accommodation apparatus of the second embodiment.

  Before the call agent 22 is switched, the call agent 22 holds subscriber information of the VoIP gateway 26, and the VoIP gateway 26 is accommodated in the call agent 22.

  The VoIP gateway 26 acquires the IP address I22 of the call agent 22 from the DHCP server 25, transmits and receives a call control message to and from the call agent 22, and the call agent 22 performs call control.

  Next, a new call agent 23 is connected to the network 21 and installed.

  At this time, when newly establishing a new call agent 23, the call agent 22 moves the stored subscriber information of the VoIP gateway 26 to the newly established call agent 23 (step S20).

  Further, the call agent 23 sets the activation of the forwarding function unit 23a (step S21). At this time, the forwarding function unit 23a is set so that the transmission destination address of the packet addressed to the call agent 23 is converted into the IP address I22 of the old call agent 22 and transferred.

  Thereafter, the IP address I22 of the call agent 22 set in the DHCP server 25 is changed to the IP address I23 of the new call agent 23 (step S22).

  Here, after the call server IP address setting is changed in the DHCP server 25, the VoIP gateway 26 makes a request to the DHCP server 25 according to the DHCP procedure (step S23). Since resetting (including resetting of the IP address of the call agent) is performed, the VoIP gateway 26 that has performed DHCP access sequentially transmits a call control message to the newly established call agent 23 (step S24).

  When the call control message from the VoIP gateway 26 is given to the call agent 23, the forwarding function unit 23a of the call agent 23 forwards the received call control message to the call agent 22 (step S25).

  When the call agent 22 receives the forwarded call control message from the call agent 23, the call agent 22 returns the response message to the VoIP gateway 26 to perform call control (steps S26 and S27).

  In this way, it waits for re-acquisition of configuration information from the DHCP server 25 for all VoIP gateways accommodated by the call agent 22.

  When the transfer of all the VoIP gateways to be migrated is completed and there is no call control message addressed to the call agent 22 and all the call control messages are given to the call agent 23, the forwarding function unit of the call agent 23 The setting of 23a is canceled (step S28), and the call agent 22 is disconnected.

  Further, all the migration target VoIP gateways 26 transmit and receive call control messages to and from the call agent 23 (step S29).

(B-2) Effects of Second Embodiment As described above, according to the second embodiment, the same effects as those of the first embodiment can be obtained.

(C) Third Embodiment Next, a third embodiment of the terminal accommodation switching system and method of the present invention will be described in detail with reference to the drawings.

  The third embodiment also exemplifies an embodiment in which the present invention is applied to a switching system that exchanges a call agent in a VoIP communication system with another call agent.

(C-1) Configuration and operation of the third embodiment The third embodiment differs from the first embodiment in the processing procedure for changing the subscriber accommodation of a call agent.

  The configuration of the third embodiment uses a forwarding function provided as standard in UNIX (registered trademark), Linux (registered trademark), and the like, which is included in the old call agent.

  Therefore, the forwarding device 24 shown in FIG. 2 is not used, but the other configuration is the same as that of the first embodiment, and therefore, the third embodiment will be described with reference to FIG.

  Similarly to the first embodiment, the call agent 22 is a call agent having a call control function, holds subscriber information of one or a plurality of VoIP gateways 26, and accommodates these VoIP gateways 26. is there. Further, as described above, the call agent 23 includes the forwarding function unit 22a provided as standard in UNIX (registered trademark) or the like.

  Similar to the forwarding device 24 described in the first embodiment, the forwarding function unit 22a converts the destination address of the received packet into a predetermined IP address and transfers it.

  6 and 7 are explanatory diagrams for explaining the operation of the switching process of the subscriber information accommodation apparatus according to the third embodiment.

  Before the call agent 22 is switched, the call agent 22 holds subscriber information of the VoIP gateway 26, and the VoIP gateway 26 is accommodated in the call agent 22.

  The VoIP gateway 26 acquires the IP address I22 of the call agent 22 from the DHCP server 25, transmits and receives a call control message to and from the call agent 22, and the call agent 22 performs call control.

  Next, a new call agent 23 is connected to the network 21 and installed, and the call agent 22 moves the stored subscriber information of the VoIP gateway 26 to the new call agent 23 (step S30).

  Until the transfer of subscriber information from the call agent 22 to the call agent 23 is completed, the call agent 22 does not activate the forwarding function unit 22a.

  Accordingly, when the call agent 22 receives the call control message from the VoIP gateway 26, the call agent 22 returns a response message of the call control message to the VoIP gateway 26 to perform call control (step S31).

  When the transfer of subscriber information is completed, the call agent 22 sets activation of the forwarding function unit 22a (step S32). At this time, the forwarding function unit 22a is set so that the transmission destination address of the packet addressed to the call agent 22 is converted into the IP address I23 of the new call agent 23 and transferred.

  When the call control message from the VoIP gateway 26 is given to the call agent 22, the forwarding function unit 22a of the call agent 22 forwards the received call control message to the call agent 23 (step S33).

  Thereafter, the IP address I22 of the call agent 22 set in the DHCP server 25 is changed to the IP address I23 of the new call agent 23 (step S34).

  Here, after the setting change of the IP address of the call agent is performed in the DHCP server 25, when the VoIP gateway 26 makes a request to the DHCP server 25 according to the DHCP procedure (step S35), the configuration information Since resetting (including resetting of the IP address of the call agent) is performed, the VoIP gateway 26 that has performed the DHCP access sequentially transmits call control messages to the new call agent 23 (step S36).

  Then, it waits for re-acquisition of configuration information from the DHCP server 25 for all VoIP gateways accommodated in the call agent 22.

  When the transfer of all VoIP gateways to be migrated is completed, there is no call control message addressed to the call agent 22, and all the call control messages are given to the call agent 23, the call agent 22 is removed (step S37). .

(C-2) Effects of Third Embodiment As described above, according to the third embodiment, the same effects as those of the first embodiment can be obtained.

(D) Fourth Embodiment Next, a fourth embodiment of the terminal accommodation switching system and method of the present invention will be described in detail with reference to the drawings.

  The fourth embodiment also exemplifies an embodiment when the present invention is applied to a switching system in which a call agent in a VoIP communication system is exchanged with another call agent.

  In the fourth embodiment, subscriber information held by a plurality of call agents is transferred to one call agent.

  In the fourth embodiment, the subscriber information of a plurality of call agents is integrated into one newly established call agent. As processing for changing the subscriber accommodation of the call agent, the first to third embodiments are used. The switching process described in the above can be applied.

  FIG. 8 is an explanatory diagram for explaining the subscriber accommodation changing process of the call agent according to the fourth embodiment. Note that the components and reference numerals shown in FIG. 8 correspond to the components and reference numerals described in the first embodiment shown in FIG.

  FIG. 8 shows a case where the subscriber information held by the two call agents 22-1 and 22-2 is transferred to one new call agent 23.

  FIG. 8 illustrates the case where the call agent subscriber accommodation process described in the third embodiment is applied. Since the procedure for changing the subscriber accommodation of the call agent 22-1 and the call agent 22-2 has been described in detail in the third embodiment, a description thereof will be omitted.

  The subscriber accommodation change processing of the call agents 22-1 and 22-2 does not have to be performed at the same time, and can be performed separately at the respective start timings. Further, the subscriber accommodation changing process of each call agent may be performed in parallel at the same time.

  Further, the call agent 23 is not newly provided, but may be already provided on the network. That is, it is not necessary to be a new call agent, and an existing call agent that can accommodate subscriber information can be applied.

  As described above, according to the fourth embodiment, in addition to the effects of the first to third embodiments, subscriber information held by a plurality of call agents can be integrated into one call agent. .

(E) Fifth Embodiment Next, a fifth embodiment of the terminal accommodation switching system and method of the present invention will be described in detail with reference to the drawings.

  The fifth embodiment also exemplifies an embodiment when the present invention is applied to a switching system for exchanging a call agent in a VoIP communication system with another call agent.

  In the fifth embodiment, subscriber information held by one call agent is transferred to a plurality of call agents.

  In the fifth embodiment, the subscriber information of one call agent is divided into a plurality of call agents, and the subscriber accommodation change processing of the call agent will be described in the first to third embodiments. The switching process performed can be applied.

  FIG. 9 and FIG. 10 are explanatory views for explaining the subscriber accommodation changing process of the call agent according to the fifth embodiment. In addition, the component and code | symbol shown in FIG.9 and FIG.10 show the thing corresponding to the component and code | symbol demonstrated in 1st Embodiment shown in FIG. 2 for convenience of explanation.

  9 and 10 show a case where the subscriber information held by the call agent 22 is divided into two call agents 23-1 and 23-2.

  FIGS. 9 and 10 show a case where the call agent subscriber accommodation process described in the second embodiment is applied.

  Here, as a method of accommodating the call agent subscriber information in a divided manner, a new call agent 23 assigned to each of the VoIP gateways 26-1 and 26-2 in the DHCP servers 25-1 and 25-2. (23-1 and 23-2) can be divided according to how to set the IP address.

  That is, the VoIP gateway 26-1 can be realized by changing the IP address I22 of the call agent 22 to the IP address I23-1 of the transfer destination call agent 23-1 in the DHCP server 25-1.

  As described above, according to the fifth embodiment, in addition to the effects of the first to third embodiments, the subscriber information held by a certain call agent is divided and accommodated in a plurality of call agents. Can do.

(F) Other Embodiments By performing the procedure described in the first to fifth embodiments, it is also possible to apply to replacement of a CA server (including migration to a new system) when the maintenance period expires. is there.

  In the first to fifth embodiments, the case where the number of DHCP servers existing in the VoIP communication system is one is illustrated, but a configuration in which a plurality of DHCP servers exist may be used. When each VoIP gateway needs to communicate with a DHCP server via a router, for example, a function such as a DHCP relay agent may be used.

  In the first to fifth embodiments, the configuration of a general telephone connected to the VoIP gateway has been exemplified, but an IP telephone having a VoIP compatible function including these components may be used.

  The function of each component of the system described in the above description is realized by software processing. For example, each server described above can be realized by the CPU of each server executing the processing program using the processing program stored in the ROM and data necessary for the processing.

It is explanatory drawing explaining the process of subscriber accommodation change of the call agent of 1st Embodiment. It is a whole block diagram which shows the main structures of the VoIP communication system of this invention. It is explanatory drawing explaining the process of subscriber accommodation change of the call agent of 1st Embodiment. It is explanatory drawing explaining the subscriber accommodation change process of the call agent of 2nd Embodiment. It is explanatory drawing explaining the subscriber accommodation change process of the call agent of 2nd Embodiment. It is explanatory drawing explaining the subscriber accommodation change process of the call agent of 3rd Embodiment. It is explanatory drawing explaining the subscriber accommodation change process of the call agent of 3rd Embodiment. It is explanatory drawing explaining the subscriber accommodation change process of the call agent of 4th Embodiment. It is explanatory drawing explaining the process of subscriber accommodation change of the call agent of 5th Embodiment. It is explanatory drawing explaining the process of subscriber accommodation change of the call agent of 5th Embodiment. It is explanatory drawing explaining the process of the subscriber accommodation change of the conventional call agent. It is explanatory drawing explaining the process of the subscriber accommodation change of the conventional call agent.

Explanation of symbols

20 ... VoIP communication system, 21 ... network,
22, 22-1 and 22-2 ... call agent (old), 22a, 22a-1 and 22a-2 ... forwarding function unit,
23, 23-1 and 23-1 ... call agent (new), 23a, 23a-1 and 23a-2 ... forwarding function unit,
24 ... Forwarding device, 25 ... DHCP server, 26 and 27 ... VoIP gateway, 28 and 29 ... General telephone.

Claims (4)

A plurality of terminals that perform call control and communicate with each other;
Variable address setting means for assigning a call control mediating device that mediates transfer of a call control message transmitted and received between the terminals, and giving the variable address of the call control mediating device to the terminal;
Receiving one or more first call control mediating devices that receive the setting of the variable address setting means and accommodate a plurality of the terminals;
In the terminal accommodation switching system for accommodating each accommodation terminal accommodated in each of the first call control mediation devices in one or more second call control mediation devices,
Each of the first call control mediating devices includes subscriber information moving means for transferring the held subscriber information of each of the accommodating terminals to the second call control mediating device of the switching destination.
After the transfer of the subscriber information, a call control message addressed to each first call control mediating device or each second call control mediating device is sent to each second call control mediating device or each first A message transfer means for converting and transferring to the call control mediating apparatus of
The variable address setting means changes the variable address of the call control mediating apparatus assigned to each accommodating terminal from the variable address of the first call control mediating apparatus to the variable address of the second call control mediating apparatus. A terminal accommodation switching system, comprising: a variable address changing unit.   The message transfer means comprises a physically independent dedicated transfer device, and is installed on the network in place of each of the first call control mediating devices. The terminal accommodation switching system according to 1.   The message transfer means uses an IP forwarding function provided in an operation system of each of the first call control mediating devices or each of the second call control mediating devices. The terminal accommodation switching system as described. A plurality of terminals that perform call control and communicate with each other;
Variable address setting means for assigning a call control mediating device that mediates transfer of a call control message transmitted and received between the terminals, and giving the variable address of the call control mediating device to the terminal;
One or a plurality of first call control mediating devices accommodating a plurality of the terminals in response to the setting of the variable address setting means;
Message transfer means,
In the terminal accommodation switching method of accommodating each accommodation terminal accommodated in each of the first call control mediation devices in one or more second call control mediation devices,
Each of the first call control mediating devices provides subscriber information of each of the accommodation terminals held by the second call control mediating device to be switched to be transferred,
After the transfer of the subscriber information, the message transfer means sends a call control message addressed to each first call control mediating device or each second call control mediating device to each second call control mediating device. Converted to and addressed to the first call control mediating device
The variable address setting means changes the variable address of the call control mediating device assigned to each of the accommodation terminals from the variable address of the first call control mediating device to the variable address of the second call control mediating device. A terminal accommodation switching method characterized by:

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