JP4249680B2 - Private telephone system and extension telephone accommodation method - Google Patents

Description

  The present invention relates to a private telephone system, and more particularly to a private telephone system including a private network that accommodates a plurality of IP telephones and a method for accommodating such extension telephones.

  FIG. 4 is a block diagram showing an example of the configuration of the local telephone system.

  As shown in FIG. 4, the private telephone system is capable of making incoming and outgoing calls from a plurality of extension telephones to each other and a call between the extension telephones for a wide area network (public network, Internet or WAN: Wide Area Network). The main apparatus 1 (for example, PBX: Private Branch eXchange) that performs telephone exchange control is connected to a conventional subscriber telephone 2, an IP telephone 3, etc. as an extension telephone.

  The main device 1 includes a control unit 11 that performs telephone exchange control of an extension telephone, a conventional telephone I / F unit 12 that accommodates a conventional subscriber telephone 2, and an IP telephone I / F unit 13 that accommodates an IP telephone 3. And an external line I / F unit 14 that accommodates a line of a wide area network. For example, a well-known SIP (Session Initiation Protocol) is used as the communication protocol of the IP telephone 3.

  The private telephone system as shown in FIG. 4 is capable of making and receiving calls from all extension telephones to a wide area network, and having functions such as line holding, transfer, busy display, and mutual telephone calls. It is.

  In the private telephone system shown in FIG. 4, in order to use the IP telephone 3 as an extension telephone, the telephone number and IP address information of the IP telephone 3 are stored in advance in the address management table 15 of the main apparatus 1 (extension registration). ) Need to be kept. When the main apparatus 1 is activated, no information on the IP telephone 3 is registered in the address management table 15.

  When the extension registration of the IP telephone 3 is performed in the main apparatus 1, as shown in FIG. 5, the IP telephone 3 (IP telephones A and B in FIG. 5) first requests REGISTER (registration of the current position) defined by SIP. Method) message is transmitted to the main apparatus 1.

  As shown in FIG. 6, the REGISTER message stores a Request URI for designating the type of method to be requested, a From header in which information on the sender (IP address) is stored, and information on the destination (IP address). And a Contact header in which information necessary for extension registration is stored. In SIP, only the REGISTER message stores the destination IP address in the From header as in the To header.

  When receiving the REGISTER message from the IP telephone 3, the main apparatus 1 extracts the caller's telephone number and IP address from the Contact header in the REGISTER message, and stores them in the address management table 15 in association with each other. Further, a normal response (200 OK) indicating that the message has been normally received and processed is sent back to the originating IP telephone 3, and the IP telephone 3 is recognized as an extension telephone.

  When the extension registration with respect to the main apparatus 1 is completed, the IP telephone 3 (IP telephone A in FIG. 5) that performs the transmission process transmits an INVITE (method for calling a user) message defined by SIP to the main apparatus 1. Since the Request URI of the INVITE message includes the telephone number of the other party, the main device 1 searches the address management table 15 based on the telephone number to obtain the destination IP address, and the IP address Forward the INVITE message to The IP telephone 3 (IP telephone B in FIG. 5) that has received the INVITE message accepts the message as incoming processing and returns 180 Ringing indicating that it is calling to the main apparatus 1. When the incoming call processing is completed, a normal response (200 OK) is returned to the main apparatus 1.

  When the main device 1 receives 180 Ringing or 200 OK from the IP telephone 3 (IP telephone B), the telephone number of the other party (IP telephone A) is extracted from the Request URI in the message as described above, and the telephone The address management table 15 is searched based on the number to obtain the corresponding IP address, and those messages are transferred to the IP address. Thereafter, a call with the two IP telephones 3 (IP telephones A and B) is established by transmitting and receiving packets including voice.

  By the way, in the private telephone system, as shown in FIG. 4, a small network (hereinafter referred to as a private network) accommodating a plurality of IP telephones 5 is passed over a NAPT (Network Address Port Translation) router 4 and A configuration connected to the IP telephone I / F unit 13 is also conceivable. The NAPT router 4 is a router that relays SIP messages having an IP address and port number conversion function.

  In that case, the IP telephone 5 realizes extension registration with respect to the main apparatus 1 by rewriting the REGISTER message as follows.

  When the IP telephone 5 in the private network performs extension registration with the main apparatus 1, first, the IP telephone 5 transmits a REGISTER message defined by SIP to the NAPT router 4 as described above. At this time, the phone number of the own device and the IP address of the NAPT router 4 on the wide area network side are stored in the Contact header of the REGISTER message.

  When the NAPT router 4 receives the REGISTER message from the private network, the NAPT router 4 transfers the REGISTER message to the main apparatus 1. The NAPT router 4 forwards the message sent from the IP telephone 5 to the NAPT router 4 to the main device 1 and created in advance by the system administrator or the like, and the message sent from the main device 1 to the NAPT router 4 Is input a conversion table for transferring to the IP telephone 5. The NAPT router 4 converts the destination to the IP address of the main device 1 according to the conversion table, and transfers the REGISTER message to the converted IP address.

  As shown in FIG. 7, the conversion table provided in the NAPT router 4 includes an IP address on the wide area network side (external IP address) and its use port, an IP address on the private network side (internal IP address) and its use port. Are stored in association with each other. FIG. 7 shows an example having entries for mutually converting between the external IP address “GB” −used port “5060” and the internal IP address “PB” —used port “5060”.

  When the main device 1 receives the SIP message from the NAPT router 4, it analyzes the SIP message to determine whether it is a REGISTER message. If it is a REGISTER message, the main device 1 reads the telephone number (extension) from the Contact header. Number) and IP address are extracted, and the extracted IP address is stored in the address management table 15 in association with the telephone number as shown in FIG. FIG. 7 shows an example in which the telephone number (extension number) is “100” and the IP address of the NAPT router is “GB”.

  When making a call to the IP telephone (extension number “100”) 5 in the registered private network, the main device 1 refers to the address management table 15 and acquires the corresponding IP address from the destination telephone number. The INVITE message is transmitted to the NAPT router 4 having the IP address.

  The NAPT router 4 converts the destination IP address of the received message according to the conversion table, and transfers it to the IP telephone 5 having the converted IP address.

  By performing the processing as described above, the IP telephone 5 in the private network can also be used as an extension telephone managed by the main apparatus 1.

In addition, in order to enable communication of computers and applications between a wide area network and a private network, an example of converting an IP address and a port number according to each network by an address conversion device arranged between the wide area network and the private network. Is described in Patent Document 1.
JP 2004-72291 A

  However, in the conventional private telephone system as described above, since the main unit registers only the extension number and the corresponding IP address in the address management table, as described above, when registering an IP telephone in the private network as an extension, The IP address of the NAPT router is registered in relation to the extension number of the IP telephone. Usually, since the NAPT router has one IP address, the number of IP telephones uniquely corresponding to the IP address is limited to one.

  Accordingly, in the case of a conventional private telephone system having a private network that accommodates a plurality of IP telephones, only one IP telephone can be registered as an extension. Therefore, all the IP telephones in the private network are used as extension telephones managed by the main unit. There was a problem that could not be registered.

  The present invention has been made to solve the above-described problems of the prior art, and in a private telephone system including a private network that accommodates a plurality of IP telephones, all the IP telephones in the private network are connected. It is an object of the present invention to provide a private telephone system that can be registered as an extension telephone in a main device and a method for accommodating the extension telephone.

In order to achieve the above object, the local telephone system of the present invention includes a NAPT router that relays a SIP message,
In the REGISTER message defined by SIP, the phone number of the own device, the IP address on the wide area network side of the NAPT router and the port number of the NAPT router allocated in advance to the own device are stored, and the REGISTER message is stored in the REGISTER message. An IP telephone housed in a private network under the NAPT router that transmits to the NAPT router;
Upon receiving the REGISTER message from the IP phone via the NAPT router, the telephone number of the IP phone that is the source, the IP address and the port number are extracted from the REGISTER message, respectively, and the IP address and port Numbers are stored in a table in association with the telephone number, and when making a call to the IP telephone, the table is referenced based on the destination telephone number obtained from the SIP message, and the corresponding IP address and port A main apparatus to which the private network is connected via the NAPT router, each acquiring a number, and transmitting the SIP message to the port of the NAPT router corresponding to the acquired IP address and port number;
It is set as the structure which has.

Further, in the extension telephone accommodating method of the private telephone system of the present invention, the IP telephone accommodated in the private network under the NAPT router that relays the SIP message is added to the REGISTER message defined by SIP in the telephone number of the device, Store the IP address on the wide area network side of the NAPT router and the port number of the NAPT router assigned to the device in advance and send it to the NAPT router,
When the main device to which the private network is connected via the NAPT router receives the REGISTER message from the IP phone via the NAPT router, the telephone number of the IP phone that is the source from the REGISTER message, the IP Extracting the address and the port number, respectively, and associating the IP address and the port number with the telephone number and holding it as a table;
When the main device makes a call from the main device to the IP phone, the corresponding IP address and port number are obtained by referring to the table based on the destination telephone number obtained from the SIP message. The SIP message is transmitted to the port of the NAPT router corresponding to the acquired IP address and port number.

  In the private telephone system and the extension telephone accommodation method as described above, when an IP telephone in a private network is registered as an extension to the main unit, the IP address and the port number are associated with each telephone number and stored in the address management table. Therefore, even if the IP address is duplicated, if the port number is set to a different value, the transmission destination corresponding to each telephone number can be uniquely determined.

  According to the present invention, even when there are a plurality of IP telephones in the private network, all of them can be registered as extension telephones of the main apparatus.

  Next, the present invention will be described with reference to the drawings.

  As described above, in the conventional private telephone system, when an IP telephone is registered as an extension to the main apparatus, only the IP address is registered in the address management table in relation to the telephone number of the IP telephone. In the local telephone system of the present invention, the IP address of the NAPT router and the port number assigned in advance to each IP telephone are registered in the address management table of the main unit in relation to the telephone number of the IP telephone. In addition, not only the IP address of the NAPT router but also the port number are stored in the Contact header of the REGISTER message transmitted from the IP telephone.

  When receiving the REGISTER message from the IP phone, the main device 1 extracts the IP address and the port number from the Contact header, and stores them in the address management table in association with the phone number of the IP phone. When making a call to an IP telephone in the private network, the corresponding IP address and port number are extracted based on the telephone number of the IP telephone, and an INVITE message is transmitted with the extracted IP address and port number. At this time, since the destination is the IP address of the NAPT router, the INVITE message is transmitted to the NAPT router. The NAPT router extracts the port number from the received INVITE message, converts the destination IP address based on the port number, and forwards the INVITE message to the IP telephone having the converted IP address. The configuration of the private telephone system is the same as that of the conventional private telephone system shown in FIG. Hereinafter, the reference numerals given to the respective components are the same as those in the conventional private telephone system shown in FIG.

  Next, the operation of the private telephone system of the present invention will be described with reference to FIGS.

  FIG. 1 is a sequence diagram showing a processing procedure at the time of extension registration by an IP telephone of the private telephone system of the present invention, and FIG. 2 is a schematic diagram showing a configuration of a REGISTER message transmitted from the IP telephone of the present invention. FIG. 3 is a schematic diagram showing an example of the configuration of the conversion table provided in the NAPT router and the address management table provided in the main apparatus constituting the private telephone system of the present invention.

  First, processing at the time of extension registration of the IP telephone 5 will be described with reference to FIGS.

  In the following, a case where the private network IP telephone 5 is registered as an extension in the main apparatus 1 will be described as an example. However, for the IP telephone 3 directly connected to the IP telephone I / F unit 13 of the main apparatus 1, As in the present invention, the telephone number, IP address, and port number may be stored and managed in the address management table 15, respectively, and the telephone number and IP address may be stored and managed in the address management table 15 as in the prior art. Also good.

  The processing of the IP telephone 5 described below is controlled by a control unit (not shown) included in the IP telephone 5, and the processing of the main device 1 is controlled by the control unit 11 included in the main device. . These control units can be realized by, for example, a CPU, a DSP, a logic circuit, or the like.

  As shown in FIG. 1, when requesting extension registration to the main apparatus 1, the IP telephone 5 in the private network transmits a REGISTER message to the main apparatus 1 across the NAPT router 4 as in the prior art.

  As shown in FIG. 2, the REGISTER message used in the present invention includes a Request URI for designating the type of method to be requested, a From header in which source information (IP address) is stored, and destination information (IP address). ) And a Contact header in which information necessary for extension registration is stored. As shown in FIG. 2, in the present invention, not only the IP address but also the port number are stored in the address designation part of the Contact header. The IP address in the Contact header stores the IP address (external IP address) of the NAPT router 4 on the wide-area network side, and the port number is for standby provided in a plurality of NAPT routers 4 assigned in advance to each IP telephone 5. Stores the port number. In FIG. 2, the source telephone number (extension number) is “100”, the IP address of the NAPT router 4 on the wide area network side is “GB”, the IP address of the destination (main device 1) is “GA”, and the assigned port In this example, the number is “5060”.

  As a method for acquiring the IP address on the wide-area network side of the NAPT router 4 and the port number of the NAPT router 4 by the IP phone 5, a method in which the system administrator inputs these information into the IP phone in advance or publicly known There is a method of acquiring from the NAPT router 4 by using a NAT traversal function defined by UPnP (Universal Plug and Play). These pieces of information are stored in a storage device (not shown) of the IP telephone 5 in a table format, for example.

  When the NAPT router 4 receives the REGISTER message from the private network, the NAPT router 4 transfers the REGISTER message to the main apparatus 1. The NAPT router 4 forwards the message sent from the IP telephone 5 to the NAPT router 4 to the main device 1 and created in advance by a system administrator or the like, and the message sent from the main device 1 to the NAPT router 4 Is input a conversion table for IP address conversion for transferring to the IP telephone 5. The NAPT router 4 transfers the REGISTER message to the main apparatus 1 according to the conversion table.

  As shown in FIG. 3, the conversion table of the NAPT router 4 includes an IP address (external IP address) on the wide area network side and its used port, and a corresponding IP address (internal IP address) on the private network side and its use. Associate and store ports. FIG. 3 shows a first entry for mutually converting the external IP address “GB” —the used port “5060” and the internal IP address “PB” —the used port “5060”, and the external IP address “GB”. -Shows an example having a use port "5061" and an internal IP address "PC"-use port "5060" and a second entry for converting between each other.

  When the main device 1 receives the SIP message from the NAPT router 4, the main device 1 analyzes the SIP message to determine whether it is a REGISTER message. Extract the phone number from the previous string. In the example shown in FIG. 2, “100” corresponds. The telephone number may be extracted from the Request URI, From header, or To header.

  The main device 1 extracts the IP address and the port number from the part after the @ mark of the Contact header. At this time, if the port number cannot be extracted, the SIP default value “5060” is set as the port number.

  Next, the main apparatus 1 associates the extracted IP address and port number with the telephone number and registers them in the address management table 15 as shown in FIG. 3 (telephone number “100” —IP address “GB”: port number “ 5060 "). If the same phone number has already been registered, or if the combination of IP address and port number overlaps with the registered information, it may be overwritten with new information, and the registration request will be rejected without overwriting. Also good.

  FIG. 3 shows an extension number “100” —IP address “GB”: a first entry of port number “5060”, a second entry of extension number “200”, IP address “GB”, and port number “5061”. The example which has is shown.

  When registration in the address management table 15 is completed, the main device 1 returns a normal response (200 OK) indicating that the message has been normally received and processed to the IP phone 5 of the transmission source, and the IP phone 5 is connected to the extension. Recognize as a telephone. Upon receiving a normal response (200 OK) from the main device 1, the NAPT router 4 transfers the normal response (200 OK) to the IP telephone 5 that is the source of the REGISTER message.

  Next, the processing at the time of transmission to the IP telephone 5 registered by extension by the main apparatus 1 will be described with reference to FIG.

  For example, when making a call to the IP telephone 5 having the extension number “200”, the main apparatus 1 refers to the address management table 15 shown in FIG. 3 and starts receiving the corresponding IP address “GB” from the destination telephone number “200”. The port number “5061” is extracted, and the INVITE message is transmitted to the port “5061” of the IP address “GB”. In this case, since the IP address of the transmission destination is the NAPT router 4, the INVITE message transmitted from the main apparatus 1 is transmitted to the port “5061” of the NAPT router 4.

  When the NAPT router 4 receives the INVITE message from the main device 1, it converts the IP address from “GB” to “PC” and the port number “5061” to “5060” according to the conversion table shown in FIG. Then, the INVITE message is transferred from the port “5060” to the IP address “PC” (IP telephone 5 having the telephone number “200”).

  Thus, according to the SIP protocol, the IP telephone 5 can perform a call by executing the process at the time of extension registration of the IP telephone 5 with respect to the main device 1 and the process at the time of outgoing call to the IP telephone 5 registered with the extension. become.

  According to the present invention, when the IP telephone 5 in the private network is registered with the main apparatus 1 as an extension, the IP address and port number of the NAPT router 4 are stored in the address management table in association with each telephone number. Even if the addresses are duplicated, if the port number is set to a different value, the transmission destination corresponding to each telephone number can be uniquely determined. Therefore, even when there are a plurality of IP telephones 5 in the private network, it is possible to register all of them as extension telephones of the main apparatus 1.

  In the above description, the REGISTER message is transmitted from the IP telephone 5 to the main apparatus 1, the IP address and the port number are extracted from the message, and registered in the address management table 15 of the main apparatus 1. At the time of initial setting or the like, the system administrator may store such information in the address management table of the main device 1.

  In that case, the main device 1 is provided with a programming mode function capable of changing the internal setting by inputting a password or the like, and the system administrator uses the programming mode to specify an IP address and a port number corresponding to each telephone number. Enter it. Even with such a method, the same effect as described above can be obtained.

It is a sequence diagram which shows the process sequence at the time of the extension registration by the IP telephone of the private telephone system of this invention. It is a schematic diagram which shows the structure of the REGISTER message which the IP telephone of this invention transmits. It is a schematic diagram which shows the example of 1 structure of the conversion table with which the NAPT router which comprises the local telephone system of this invention is provided, and the address management table with which the main apparatus is provided. It is a block diagram which shows one structural example of a local telephone system. It is a sequence diagram which shows the procedure of the registration process by the IP telephone according to a SIP protocol, a transmission process, and an incoming call process. It is a schematic diagram which shows the structure of the REGISTER message which the conventional IP telephone transmits. It is a schematic diagram which shows the structure of the conversion table with which the NAPT router which comprises the conventional private telephone system, and the address management table with which the main apparatus are provided.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main apparatus 2 Subscriber telephone 3, 5 IP telephone 4 NAPT router 11 Control part 12 Conventional telephone I / F part 13 IP telephone I / F part 14 Outside line I / F part 15 Address management table

Claims (6)

A NAPT router that relays SIP messages;
In the REGISTER message defined by SIP, the phone number of the own device, the IP address on the wide area network side of the NAPT router and the port number of the NAPT router allocated in advance to the own device are stored, and the REGISTER message is stored in the REGISTER message. An IP telephone housed in a private network under the NAPT router that transmits to the NAPT router;
Upon receiving the REGISTER message from the IP phone via the NAPT router, the telephone number of the IP phone that is the source, the IP address and the port number are extracted from the REGISTER message, respectively, and the IP address and port Numbers are stored in a table in association with the telephone number, and when making a call to the IP telephone, the table is referenced based on the destination telephone number obtained from the SIP message, and the corresponding IP address and port A main apparatus to which the private network is connected via the NAPT router, each acquiring a number, and transmitting the SIP message to the port of the NAPT router corresponding to the acquired IP address and port number;
A private telephone system. The NAPT router
Transferring SIP message received from the IP phone to the main device, comprising a conversion table for transferring the SIP message received from the main device to a destination IP phone,
2. The IP address of the destination of the SIP message is converted according to the conversion table based on the port number obtained from the received SIP message, and the SIP message is transferred to the IP address after conversion. Premises phone system. An IP phone that is accommodated in a private network under the NAPT router that relays the SIP message is assigned to the REGISTER message specified by SIP, its own phone number, the IP address of the NAPT router on the wide area network side, and its own device. Store the port number of the NAPT router provided and send it to the NAPT router,
When the main device to which the private network is connected via the NAPT router receives the REGISTER message from the IP phone via the NAPT router, the telephone number of the IP phone that is the source from the REGISTER message, the IP Extracting the address and the port number, respectively, and associating the IP address and the port number with the telephone number and holding it as a table;
When the main device makes a call from the main device to the IP phone, the corresponding IP address and port number are obtained by referring to the table based on the destination telephone number obtained from the SIP message. A method for accommodating extension telephones in a private telephone system, wherein the SIP message is transmitted to a port of the NAPT router corresponding to the acquired IP address and port number. The NAPT router
Transferring the SIP message received from the IP phone to the main device, a conversion table for transferring the SIP message received from the main device to the destination IP phone,
4. The IP address of the destination of the SIP message is converted according to the conversion table based on the port number obtained from the received SIP message, and the SIP message is transferred to the IP address after conversion. Extension telephone accommodating method of the local telephone system. An IP phone accommodated in a private network under a NAPT router that relays SIP messages,
A storage device that stores the telephone number of the own device, the IP address on the wide area network side of the NAPT router, and the port number of the NAPT router assigned to the own device;
In the REGISTER message defined by SIP, the telephone number of the own device, the IP address on the wide area network side of the NAPT router and the port number of the NAPT router assigned to the own device are stored, and the REGISTER message is stored. A control unit for transmitting to the NAPT router;
IP phone with. A main device that performs telephone exchange control,
Address management table in which the IP address on the wide-area network side of the NAPT router that relays the SIP message and the port number of the NAPT router assigned in advance to each IP telephone are stored in association with the telephone number of the originating IP telephone When,
Upon receiving the REGISTER message from the IP phone via the NAPT router, the telephone number of the IP phone that is the source, the IP address and the port number are extracted from the REGISTER message, respectively, and the IP address and port When a number is stored in the address management table in association with the telephone number and is transmitted to the IP telephone, the corresponding IP address and port are referenced by referring to the table based on the telephone number of the destination obtained from the SIP message. A controller that obtains each number, and transmits the SIP message to the port of the NAPT router corresponding to the obtained IP address and port number;
Main device having.

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