This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2006-265979, filed Sep. 28, 2006, the entire contents of which are incorporated herein by reference.
1. Field
One embodiment of the invention relates to, for example, an Internet protocol (IP) telephone system. More specifically, the present invention relates to a main apparatus of a communication system configured to make voice communications among a plurality of communication terminals and an IP network through interface units, and a registration method for use in the main apparatus.
2. Description of the Related Art
In recent years, a network telephone system (IP telephone system) which interactively transmits and receives an image and a voice as packet data in real time has become widely used. Such an IP telephone system may perform extension communications and outside line outgoing/incoming calls among main apparatus via the IP network as well as perform extension communications and outside line outgoing/incoming calls for each main apparatus connected to the IP network. The IP telephone system has widely used a session initiation protocol (SIP) as its protocol.
This type of system associates URI (terminal ID) of an extension terminal for each main apparatus with identification information (connection ID) of an interface to be used for a connection with the IP network to pre-register it in a server of an enterpriser on the IP network. When makes speeches through the IP network by means of the extension terminals, a server authenticates the extension terminals based on the association between the registered terminal IDs and connection IDs.
The system may register a plurality of interfaces to which the extension terminals are connected in association with priorities in registering the terminal IDs and connection IDs in the server. Therefore, when an interface with the top priority becomes fault, if an incoming call arrives at the extension terminal accommodated in the interface, a first incoming call does not terminate due to the fault of the interface, but the system tray to terminate the first incoming call by shifting to an interface with the next top priority, so that the system becomes able to terminate the incoming call while detouring the fault interface as a result. However, the incoming call is delayed until it is determined that the first incoming call is invalid. Since the system shifts only within a pre-registered range, if all interfaces go wrong, the incoming call may not be terminated.
Conventionally, a concentrator system, which has a plurality of lines to the IP network, reds out a fault state of connection lines, treats the fault connection lines as non-selection objects and connects the terminal to another line if the connection line is in fault, has been proposed (e.g., Jpn. Pat. Appln. KOKAI Publication 2003-111116).
However, when the foregoing concentrator system is applied to an SIP, it becomes necessary to associate between a server of an enterpriser on the IP network and the plurality of lines in advance to register them.
A general architecture that implements the various feature of the invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the invention and not to limit the scope of the invention.
FIG. 1 is a preferred block diagram illustrating a configuration of an IP network communication system regarding the first embodiment of the invention;
FIG. 2 is a preferred view illustrating a correspondence relation with identification information (connection ID) of local area network (LAN) interfaces which is stored in a database depicted in FIG. 1, and is associated with URIs that are client information to be registered in each enterpriser in accordance with extensions;
FIG. 3 is a preferred view illustrating the number of sessions which is stored in the database depicted in FIG. 1 and is connectable to each enterpriser for each LAN interface unit at the same time;
FIG. 4 is a preferred view illustrating traffic (the averaged number of calls) which is stored in the database depicted in FIG. 1 and is registered for each enterpriser in accordance with extensions;
FIG. 5 is a preferred view illustrating re-distribution registration system to be stored in the database depicted in FIG. 1;
FIG. 6 is a preferred flowchart illustrating a control processing procedure of a registration control unit which re-registers URIs associated with the LAN interface units when an fault occurs at any of the LAN interface units in the first embodiment of the invention; and
FIG. 7 is a preferred view illustrating a management table in which traffic is re-distributed in the first embodiment of the invention.
Various embodiments according to the invention will be described hereinafter with reference to the accompanying drawings. In general, according to one embodiment of the invention, a main apparatus of a communication system which accommodates a plurality of communication terminals and enables being connected with a packet communication network including at least one registration server via a plurality of interface units, comprising: a communicator which registers a first management table in which terminal IDs specifying the plurality of communication terminals are associated with connection IDs specifying the plurality of interface units to the registration server, to communicate between the communication terminals and the packet communication network through each session of the plurality interface units; and a controller which updates the first management table registered in the registration server to a second management table in which association among the terminal IDs and the connection IDs is changed based on prescribed conditions.
FIG. 1 is a block diagram showing a configuration of an IP network communication system regarding the first embodiment of the invention, and the symbol 1 indicates a main apparatus.
A gateway GW is connected to the main apparatus 1 via a local area network (LAN) 2 - 1 . The gateway GW connects between an IP network IPN and the LAN 2 - 1 , and has a conversion function for a communication protocol and a signal format between the IP network IPN and the LAN 2 - 1 .
Further, registration servers RA and RB of a plurality of enterprisers are connected to the IP network IPN. To make the description short, FIG. 1 shows only two registration servers RA and RB.
The main apparatus 1 has extension interface units S 1 and S 2 , LAN interface units L 1 -L 4 , a registration control unit C 1 , and databases DB 1 -DB 4 .
LAN interface units L 1 -L 3 perform interface processing to and from the LAN 2 - 1 .
The LAN interface unit L 4 accommodates a LAN 2 - 2 , and an IP extension terminal IT 1 is connected to the LAN 2 - 2 . The LAN interface unit L 4 conducts an interface operation such as outgoing and incoming call processing to and form the IP extension terminal IT 1 . The LAN interface unit L 4 conducts transmissions and receptions of a variety of items of control information concerning the interface operation for the LAN 2 - 2 to and from the registration control unit C 1 . An extension number (DN: 203 ) is assigned to the IP extension terminal IT 1 as a terminal ID.
The extension interface unit S 1 accommodates extension terminals ST 1 and ST 2 . The extension interface S 1 performs interface operations for the extension terminals ST 1 and ST 2 . The extension interface S 1 transmits and receives a variety of kinds of control information regarding the interface operations for the extension terminals ST 1 and ST 2 to and from the control unit C 1 . An extension number (DN: 200 ) is assigned to the extension terminal ST 1 , and an extension number (DN: 201 ) is assigned to the extension terminal ST 2 .
The extension interface unit S 2 accommodates an extension terminal ST 3 . The extension interface unit S 2 conducts an interface operation of outgoing and incoming call processing, etc., to the extension terminal ST 3 . The extension interface unit S 2 transmits and receives a variety of kinds of control information concerning interface operations to and from the control unit C 1 . An extension number (DN: 202 ) is assigned to the extension terminal ST 3 .
The database DB 1 stores, as shown in FIG. 2, identification information (connection ID) of the LAN interface units L 1 -L 3 associated with a URI that is client information to be registered in each enterpriser in accordance with extensions.
The database DB 2 stores, as depicted in FIG. 3, how many sessions can be connected at the same time in each enterpriser for each LAN interface unit L 1 -L 3 .
The database DB 3 , as shown in FIG. 4, stores traffic (the number of averaged calls) for each enterpriser in accordance with extensions.
The database DB 4 stores, as illustrated in FIG. 5, a system how to re-distribute and register the URI when any fault occurs in the LAN interface units for each enterpriser A and B into the remaining LAN interface unit.
The control unit C 1 includes a fault monitoring unit 11 , a re-registration control unit 12 , a recovery monitoring unit 13 and a traffic storage unit 14 (hereinafter referred to as storage unit 14 ) in addition to a control function to realize an operation as the main apparatus 1 . The fault monitoring unit 11 monitors fault occurrences in the LAN interface units L 1 -L 3 .
When a fault is detected by the monitoring unit 11 , the control unit 12 refers to the storage contents of the database DB 2 -DB 4 , associates the extension terminals ST 1 -ST 3 , and IP extension terminal IT 1 with normal LAN interface units L 1 and L 2 , updates the storage content of the database DB 1 , further, and makes communications with the registration servers RA and RB to execute re-registration of the update content of the database DB 1 for the registration servers RA and RB.
The recovery monitoring unit 13 monitors a recovery situation of the LAN interface unit L 3 in which a fault has occurred.
When the recovery monitoring unit 13 detects the fact of the recovery of the defected LAN interface unit L 3 , the re-registration control unit 12 returns the storage content of the database DB 1 as before, and makes communications with the registration servers RA and RB to return the update content of the database DB 1 for the registration servers RA and RB as it was before.
The storage unit 14 measures each pieces of traffic of the extension terminals ST 1 -ST 3 , and the IP extension terminal IT 1 to store them. The storage unit 14 obtains average of the periodically stored each pieces of traffic of the extension terminals ST 1 -ST 3 and IP extension terminal IT 1 to store them in the database DB 3 .
Next to this, operations of the IP network communication system configured as mentioned above will be described.
FIG. 6 is a flowchart depicting a control processing procedure of the registration control unit C 1 to re-register the URI associated to the LAN interface unit L 3 in the case of an occurrence of a fault in the LAN interface unit L 3 .
The control unit C 1 firstly extracts the fact that the extension numbers associated to the LAN interface unit L 3 are two of DN: 202 , and DN: 203 by referring to the database DB 1 (block ST 6 a ).
Next, the control unit C 1 extracts the fact that the extension numbers DN 202 and 203 are associated with the enterprisers A and B, respectively, from a reference result to the database DB 1 (block ST 6 b ).
The control unit C 1 re-registers association information to an enterpriser A in accordance with the following method. Obtaining a ratio of the number of sessions between the remaining normal LAN interface units L 1 and L 2 by referring to the database DB 2 (block ST 6 c ) results in an expression, L 1 :L 2 =1:1.
A re-registration distribution system of the enterpriser ‘A’ decides to obtain a ratio of the number of sessions with reference to the database DB 4 . The control unit C 1 then shifts from a block ST 6 d to a block ST 6 e , and there, distributes the DN 202 and DN 203 by means of the ratio of the number of sessions of 1:1.
As shown in FIG. 7, the resulting distribution generates a management table in which the DN 202 , and DN 203 are re-distributed to the LAN interface units L 1 and L 2 one by one, respectively, to register this management table in the registration server RA of the enterpriser A (block ST 6 f ). At this moment, the management table is inserted into a REGISTER request defined by the SIP and transmitted to the registration server RA.
As described above, in the first embodiment, for example, in the case of an occurrence of a fault at a LAN interface unit L 3 , the main apparatus 1 refers to the databases DB 2 -DB 4 , associates the terminal ID (DN 202 ) of the extension terminal ST 3 with the connecting ID (1) of the normal LAN interface unit L 1 based on the reference result, creates the management table in which the terminal ID (DN 203 ) of the IP extension terminal IT 1 is associated with the connection ID (2) of the normal LAN interface unit L 2 , and updates the registration content of the registration server RA of the enterpriser A on the IP network IPN to the content of the management table as well as updates the storage content of the database DB 1 to the content of the management table.
Accordingly, in the case in which the LAN interface unit L 3 is not available due to the occurrence of the fault, the registration control unit C 1 can register the re-associated management table in the registration server RA of the enterpriser A, thereby the LAN interface unit L 3 to be used in connecting the extension terminal ST 3 and the IP extension terminal IT 1 to the IP network IPN automatically switches to the normal LAN interface units L 1 and L 2 , and then the control unit C 1 may continue the voice communication.
The user of the main apparatus 1 may register association information among the extension terminals ST 1 -ST 3 , the IP extension terminal IT 1 and the interface units L 1 -L 3 only once in the registration server RA of the enterpriser A, thereby the registration operation may be simplified extremely. Further, as long as the normal LAN interface units L 1 and L 2 exist, the control unit C 1 can execute the re-registration of the management table to the registration server RA repeatedly.
In the first embodiment, when the fault of the LAN interface unit L 3 of the main apparatus 1 is recovered, the connection between the IP extension terminal IT 1 and the LAN interface unit L 3 which have been associated with each other firstly is recovered automatically.
Therefore, for instance, when the fault of the LAN interface unit L 3 is returned to normal, the control unit C 1 may quickly recover the connection among the firstly associated extension terminal ST 3 , IP extension terminal IT 1 and LAN interface unit L 3 without having to wait for a recovery operation by a maintenance person.
Moreover, in the first embodiment, the re-associated management table may be re-registered in the server RA by the use of the existing registration request such as the REGISTER request defined by the SIP.
Accordingly, there is no need to newly set an exclusive signal and re-register the management table to the registration server RA again; and thereby the registration processing may be implemented directly through a further simple processing procedure.
The second embodiment of the invention is related to an example of re-registering association information to the registration server RB of the enterpriser B.
The control unit C 1 obtains a ratio between the numbers of sessions of the remaining normal LAN interface units L 1 and L 2 as, L 1 :L 2 =1:1, by referring to the database DB 2 .
Here, the re-registration distribution system of the enterpriser B decides a distribution ratio as a traffic ratio with reference to the database DB 4 .
The control unit C 1 shifts from the block ST 6 d to a block ST 6 g , there distributes the sessions so that the traffic ratio becomes equivalent to ‘1:1’ that is the session ratio as much as possible. That is, since the current traffic ratio of the LAN interface unit L 1 to the LAN interface unit L 2 is equivalent to the ratio of the extension numbers DN 200 to the DN 201 , the resulting ratio becomes, 10:5=2:1. Because the ratio of the numbers of sessions is ‘1:1’, the control unit C 1 intends to approach the ratio of traffic in distributing the extension numbers DN 202 and DN 203 becomes close to ‘1:1’ as much as possible.
To make it true of a ratio between traffic of the extension with the extension number DN 200 +traffic of a extension re-distributed to the interface unit L 1 and traffic of the extension with the extension number DN 201 +traffic of the extension re-distributed to the interface unit L 2 =1:1, if the control unit C 1 distributes the extension with DN 203 to the interface unit L 1 , and the extension with DN 202 to the interface unit L 2 , it becomes true for the formula, 10+5:5+10=15:15=1:1.
As a result, the control unit C 1 re-assigns the extension with DN 202 to the interface unit L 2 , and the extension with DN 203 to the interface unit L 1 one by one to create the management table, then, registers the management table to the registration server RB of the enterpriser B.
The procedure given above completes the re-registration of the URIs to be connected to the enterpriser associated with the defected LAN interface unit L 3 , then; the control unit C 1 terminates the processing. At this moment, the content of the database DB 1 has been changed to that of the management table depicted in FIG. 7.
As mentioned above, in the second embodiment, since the control unit C 1 executes comparison determination etc. between the ratio of total traffic of the extension terminals ST 1 , ST 2 , ST 3 , and IP extension terminal IT 1 and the ratio of the number of available sessions associated to each normal LAN interface unit L 1 and L 2 by using averaged traffic for each extension terminal ST 1 , ST 2 , ST 3 and IP extension terminal IT 1 stored and managed in and by the database DB 3 , the control unit C 1 may perform association processing of the extension terminals ST 1 , ST 2 , ST 3 and IP extension terminal IT 1 to the normal LAN interface units L 1 and L 2 with a simple procedure.
The invention is not limited to each embodiment given above. While each embodiment mentioned above has been described about the example to connect the IP network to the main device through the gateway, having the gateway built-in the master device to directly connect the IP network is a possible approach.
Although each embodiment described above has been described about the example to use the REGISTER request of the SIP and reregister the association information to the registration server of the enterpriser on the IP network, it is understood that the re-registration of the association information to the registration server of the enterpriser on the IP network may be carried out by using a protocol other than the SIP.
Other than this, a type and a configuration of a system, a configuration of a master device, a kind of an extension terminal such as a communication terminal, a storage content of each database, a fault detection control procedure and a re-registration control procedure in a LAN interface unit, etc., may be achieved depending on various modifications without departing from the spirit of the invention.
While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.