JP2010147690A - Ip telephone communication device, ip telephone communication relay device, and ip telephone communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IP telephone communication device that executes SIP communications for reducing a processing load of a SIP server. <P>SOLUTION: The IP telephone communication device transmits a communication request, including a telephone number of a communication destination, to a SIP server so as to execute communication with a communication-destination IP telephone communication device via the SIP server. The device stores the telephone number and the IP address corresponding to the telephone number transmitted from the SIP server in its own storage part so as to determine whether the IP address, corresponding to the inputted telephone number, is stored in its own storage part. When stored, the device reads out the IP address, corresponding to the telephone number, from the storage part and transmits a communication request by using the read IP address as the communication destination so as to execute communication with the communication-destination IP telephone communication device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an IP telephone communication apparatus and an IP telephone communication method for performing IP telephone communication based on SIP on an IP network.

In recent years, IP telephone communication based on SIP (Session Initiation Protocol) is performed on an IP (Internet Protocol) network. In such IP telephone communication, first, the calling telephone terminal transmits a communication request with the telephone number input by the user as the communication destination to the SIP server (SIP proxy). The SIP server stores in advance address information in which a telephone number and an IP address are associated with each other, and performs an address resolution process of reading out an IP address corresponding to a communication destination telephone number received from the telephone terminal on the calling side. After that, a communication request with the read IP address as the communication destination is transmitted to the communication destination telephone terminal.
Patent Document 1 proposes a technique for performing IP telephone communication without performing address resolution processing by communicating with a SIP server by storing a telephone number and an IP address in advance in a calling terminal. Yes.
Patent Document 2 stores address information in which an IP address corresponding to a telephone number used for call connection and a MAC address are associated with each other when the IP communication apparatus performs call connection. In order to be able to cope with the change of the IP address, etc., a technique has been proposed in which address verification is performed to check whether the destination IP address and MAC address match the stored address information before completing the call connection. ing.
JP 2003-158553 A JP 2008-141585 A

  However, in the conventional method of address resolution by the SIP server, when the SIP server performs address resolution of a large number of telephone terminals, the address resolution processing load becomes large, and the address by the SIP server in IP telephone communication. It is considered that control processing such as solution and SIP communication relay causes connection delay (hereinafter, a delay associated with the control processing is referred to as a control delay). Here, with the technique described in Patent Document 1, it is not possible to perform address resolution for communication requests destined for telephone numbers that are not stored in advance. In the technique described in Patent Document 2, when communication is performed between routers that perform IP layer transfers that do not exchange L (layer) 2 MAC addresses, networks between routers have L2 broadcast domains. Unlikely, MAC addresses are not exchanged between IP communication devices. As a result, the address collation based on the MAC address does not function, and there is a problem that it is impossible to determine whether it is a desired communication partner.

  The present invention has been made in view of such a situation. The processing load imposed on the SIP server in IP telephone communication is reduced to prevent a control delay, and when the IP address of the communication destination is changed, the present invention is accurate. An IP telephone communication apparatus, an IP telephone communication relay apparatus, and an IP telephone communication method for completing a communication connection are provided.

  In order to solve the above-described problem, the present invention stores a telephone number and an IP address of a communication destination IP telephone communication apparatus, which is a communication destination by IP telephone communication, in association with each other and stores the telephone number as a communication destination. An IP telephone communication device connected via a network to a SIP server that receives a communication request based on the IP address, transmits the received communication request using an IP address corresponding to a telephone number as a communication destination, and relays SIP communication, A storage unit in which a telephone number and an IP address are stored in association with each other, a communication request including a telephone number of a communication destination is transmitted to the SIP server, and communication is performed with the communication destination IP telephone communication apparatus via the SIP server. The SIP communication control unit, the telephone number, and the IP address corresponding to the telephone number received by the first SIP communication control unit from the SIP server are stored in the storage unit. A registration unit, an input unit for inputting a communication destination telephone number, a determination unit for determining whether or not an IP address corresponding to the telephone number input to the input unit is stored in the storage unit, and a determination unit However, if it is determined that the IP address corresponding to the telephone number is stored in the storage unit, the IP address corresponding to the telephone number is read from the storage unit, and a communication request is transmitted using the read IP address as a communication destination for communication. And a second SIP communication control unit that performs communication with the destination IP telephone communication device.

  Further, according to the present invention, the date and time when the telephone number and the IP address are stored by the address registration unit is stored in the storage unit, and the determination unit has an IP address corresponding to the telephone number input to the input unit. The date and time stored in the storage unit and the current date and time are compared to determine whether or not a predetermined period has elapsed, and the first SIP communication control unit has passed the predetermined period If it is determined that the communication is being performed, a communication request is transmitted to the SIP server.

  According to the present invention, the determination unit described above determines whether or not a response to the communication request transmitted from the second SIP communication control unit to the communication destination IP telephone communication device indicates a communication error. When the SIP communication control unit determines that the response indicates a communication error, the SIP communication control unit transmits a communication request to the SIP server.

  Further, the present invention is characterized in that a non-volatile memory in which the stored telephone number and IP address are held even when the supply of power is interrupted is applied to the storage unit.

  The present invention also provides an IP telephone communication apparatus that transmits a communication request based on SIP with the telephone number of the input destination IP telephone communication apparatus as the communication destination, and the telephone number and IP address of the destination IP telephone communication apparatus. Is stored in association with each other, receives a communication request based on SIP with a telephone number as a communication destination, transmits the received communication request with an IP address corresponding to the telephone number as a communication destination, and relays SIP communication And an IP telephone communication relay apparatus connected to the storage section in which the telephone number and the IP address are stored in association with each other, and the SIP server includes the telephone number of the communication destination received from the IP telephone communication apparatus A first SIP communication control unit that transmits a communication request and communicates with a communication destination IP telephone communication device via the SIP server, a telephone number, and a telephone number transmitted from the SIP server The address registration unit that stores the IP address corresponding to the IP address in the storage unit, and determines whether or not the storage unit stores the IP address corresponding to the communication destination telephone number of the communication request received from the IP telephone communication device When the determination unit and the determination unit determine that the IP address corresponding to the telephone number is stored in the storage unit, the IP address corresponding to the telephone number is read from the storage unit, and communication is performed using the read IP address as a communication destination. And a second SIP communication control unit that transmits a request and communicates with a communication destination IP telephone communication device.

  The present invention also stores a telephone number and an IP address of a communication destination IP telephone communication apparatus which is a communication destination by IP telephone communication in association with each other, and receives a communication request based on SIP with the telephone number as a communication destination. The received communication request is connected via a network to a SIP server that transmits the IP address corresponding to the telephone number as a communication destination and relays SIP communication, and the telephone number and the IP address are stored in association with each other. The first SIP communication control unit transmits a communication request including a communication destination telephone number to the SIP server, and the communication destination IP is transmitted via the SIP server. A step of communicating with the telephone communication device, an address registration unit corresponding to the telephone number, and an IP corresponding to the telephone number received by the first SIP communication control unit from the SIP server Storing the address in the storage unit, inputting the telephone number of the communication destination to the input unit, determining unit storing the IP address corresponding to the telephone number input to the input unit stored in the storage unit The second SIP communication control unit determines an IP address corresponding to the telephone number when the determination unit determines that the IP address corresponding to the telephone number is stored in the storage unit. And a step of transmitting a communication request using the read IP address as a communication destination and communicating with the communication destination IP telephone communication device.

  As described above, according to the present invention, an IP telephone communication apparatus that transmits a communication request including a communication destination telephone number to a SIP server and communicates with the communication destination IP telephone communication apparatus via the SIP server is The number and the IP address corresponding to the telephone number transmitted from the destination IP telephone communication device via the SIP server are stored in its own storage unit, and the IP address corresponding to the input telephone number is stored in its own storage unit If it is stored, the IP address corresponding to the telephone number is read from the storage unit, a communication request is transmitted using the read IP address as the communication destination, and the communication destination IP telephone communication device The IP address acquired based on the communication performed via the SIP server is stored in its own storage unit, and the IP address corresponding to its own storage unit is stored. The communication request with the telephone number storing the communication address as the communication destination can be performed using the IP address of the communication destination IP telephone communication terminal as the communication destination, and communication can be performed without going through the SIP server. .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a block diagram showing a configuration of an IP telephone communication system 1 according to the present embodiment. The IP telephone communication system 1 includes a subscriber network 100 that is a network including a calling telephone terminal 110, a subscriber network 200 that is a network including a called telephone terminal 210, and a subscriber network 100. A carrier IP network 300 that is a communication carrier IP network connecting the subscriber network 200 is provided.

  The subscriber network 100 includes a telephone terminal 110, a SIP-UA (User Agent) 120, and a line termination device 140. The telephone terminal 110 is a telephone provided with a telephone number input button, a receiver, and the like. The SIP-UA 120 is an IP telephone apparatus that controls IP telephone communication based on SIP, and specifically, a TA (Terminal Adapter) or the like can be applied. Further, the SIP-UA 120 stores its own telephone number and IP address that are determined in advance. Here, it is assumed that the telephone number of the SIP-UA 120 is “0611111111” and the IP address is “10.1.1.1”.

FIG. 2 is a block diagram illustrating a detailed configuration of the SIP-UA 120. The SIP-UA 120 includes an A / D signal converter 121, an address information storage unit 122, a communication control unit 123, and a communication module 130.
The A / D signal converter 121 converts an analog signal transmitted from the telephone terminal 110 into a digital signal and outputs the digital signal to the communication control unit 123, and also converts the digital signal output from the communication control unit 123 into an analog signal. To the telephone terminal 110.

  The address information storage unit 122 stores address information including information in which a telephone number and an IP address are associated with each other. The address information storage unit 122 is a volatile memory that retains stored address information even when power supply is interrupted. This makes it possible to retain address information even when the power to the SIP-UA 120 is interrupted due to a power failure or the like. Thereby, it is possible to suppress an increase in temporary address resolution inquiries to the SIP server 320 immediately after a power failure or the like. FIG. 3 is a diagram illustrating an example of address information data stored in the address information storage unit 122. The address information includes information in which the item number, the communication destination telephone number, the communication destination IP address, the registration date and time, the number of outgoing calls, and the last call date and time are associated with each other.

  The item number is a number for identifying the address information stored in the address information storage unit 122. The communication destination telephone number is a numeric string representing the telephone number. The communication destination IP address is an IP address corresponding to the call destination telephone number. The registration date and time is the date and time when the communication destination telephone number corresponding to the address information storage unit 122 is stored. The number of outgoing calls is the number of times the SIP-UA 120 has sent a communication request with the corresponding communication destination telephone number as the communication request destination. The last call date and time is the last call date and time when the communication control unit 123 made a call to the corresponding communication destination telephone number.

The communication control unit 123 includes a determination unit 124, a SIP communication control unit 125, an address registration unit 128, and a telephone communication unit 129, and performs IP telephone communication based on SIP communication.
When the A / D signal converter 121 receives a communication request including the communication request destination telephone number from the telephone terminal 110, the determination unit 124 receives an IP address corresponding to the communication request destination telephone number in the address information storage unit 122. It is determined whether or not it is stored. In addition, the determination unit 124 compares the registration date and time of the address information corresponding to the communication request destination telephone number with the current date and time, and determines whether or not the difference between the registration date and the current date and time exceeds a predetermined period. judge. Here, the predetermined period is, for example, one month.

  The first SIP communication control unit 126 is determined by the determination unit 124 when the communication request destination telephone number is not stored in the address information storage unit 122, or is stored but determined from the registration date and time. When it is determined that the period has elapsed, a communication request destined for the SIP server 320 is transmitted, and SIP communication via the SIP server 320 is performed to establish a communication connection with another communication device.

  When the second SIP communication control unit 127 determines by the determination unit 124 that the communication request destination telephone number is stored in the address information storage unit 122 and the period determined from the registration date and time has not elapsed Then, the IP address corresponding to the telephone number is read from the address information storage unit 122, and a communication request with the read IP address as the communication destination is transmitted to the carrier IP network 300. In this way, the second SIP communication control unit 127 establishes a communication connection by performing SIP communication directly with the communication device of the communication destination.

When the first SIP communication control unit 126 or the second SIP communication control unit 127 establishes a communication connection with the communication destination communication device, the telephone communication unit 129 starts a call with the communication destination communication device. . The telephone communication unit 129 performs voice transmission / reception through, for example, an RTP (Real-time Transport Protocol) media session.
When the first SIP communication control unit 125 performs SIP communication via the SIP server 320, the address registration unit 128 allows the first SIP communication control unit 125 to communicate with the destination SIP-UA 220 via the SIP server 320. The address information storage unit 122 stores the combination of the telephone number and the IP address received from. In the present embodiment, the address registration unit 128 uses the Contact attribute in the SIP message (200 OK) indicating the completion of the communication connection received from the SIP-UA 220 of the communication destination via the SIP server 320, and the telephone number of the communication destination. The combination with the IP address is read and stored in the address information storage unit 122. Note that the IP address stored in the address information storage unit 122 by the address registration unit 128 may be an IP address based on information included in the SIP message received from the SIP-UA 220 of the communication destination, for example, via the SIP server 320. The combination of the communication destination telephone number and the IP address may be read out from the Contact attribute such as the SIP message (Ringing) received from the communication destination SIP-UA 220.
The communication module 130 performs information communication with other communication devices via the line termination device 140.

Returning to FIG. 1, the line termination device 140 is a device that connects the carrier IP network 300 and the subscriber network 100 via a line.
The carrier IP network 300 includes a subscriber edge router 310, a SIP server 320, and a subscriber edge router 330.
The subscriber edge router 310 is a router that connects the line termination device 140 and the SIP server 320.

The SIP server 320 performs communication control such as forwarding a received SIP message and responding to the SIP message. The SIP server 320 stores in advance address resolution information in which SIP-UA telephone numbers and IP addresses provided in the connected subscriber network are associated with each other, and performs address resolution processing.
The subscriber edge router 330 is a router that connects the SIP server 320 and the line termination device 240.

  Similar to the subscriber network 100, the subscriber network 200 includes a telephone terminal 210, a SIP-UA 220, and a line terminating device 240. The function of each computer device included in the subscriber network 200 is the same as that of each device included in the subscriber network 100. The SIP-UA 220 stores a predetermined telephone number and IP address. Here, it is assumed that the telephone number of the SIP-UA 220 is “06222222222” and the IP address is “10.2.2.2”.

Next, with reference to FIG. 4, an operation example in which the IP telephone communication system 1 according to the present invention performs IP telephone communication based on SIP will be described. Here, an example in which the SIP-UA 120 in FIG. 1 performs IP telephone communication with the SIP-UA 220 via the SIP server 320 will be described.
First, when the telephone terminal 110 receives a telephone number input from the user, it transmits a communication request to the SIP-UA 120 (step S1). Here, it is assumed that the communication request destination telephone number input to the telephone terminal 110 is “06222222222” which is the telephone number of the SIP-UA 220. The address registration unit 128 causes the address information storage unit 122 to store address information in which the telephone number indicating the communication destination of the communication request received by the A / D signal converter 121 of the SIP-UA 120 is the communication destination telephone number (step S2). At this time, the item of the communication destination IP address corresponding to the telephone number “06222222222” of the address information stored in the address information storage unit 122 is in a null state (a state in which nothing is input).

  The determination unit 124 determines whether or not the IP address corresponding to the telephone number of the communication request destination transmitted in step S1 is stored in the address information storage unit 122 (step S3). Here, when the determination unit 124 determines that the address information including the IP address corresponding to the communication request destination telephone number transmitted in step S1 is not stored in the address information storage unit 122 (step S3: mismatch) ), The first SIP communication control unit 126 makes a communication request based on the SIP to the SIP server 320 via the communication module 130 (step S4).

Here, a sequence example of SIP communication by the SIP-UA 120 will be described with reference to FIG.
The communication control unit 123 of the SIP-UA 120 transmits a SIP message (INVITE) of a communication request having “0622222222”, which is the telephone number of the SIP-UA 220, as a communication request destination telephone number to the SIP server 320 (step S30). . At this time, the address registration unit 128 of the SIP-UA 120 stores address information having “062222222” as the communication destination telephone number, but the corresponding communication destination IP address is null.

  When the SIP server 320 receives the SIP message (INVITE) of the communication request transmitted from the SIP-UA 120, the SIP server 320 receives the IP address “10.22” corresponding to the communication destination telephone number “0622222222” from the address resolution table stored in advance. 2.2.2 "is read and address resolution is performed. Then, the SIP server 320 transmits a SIP message (INVITE) of a communication request with the SIP-UA 120 as a communication request source and the SIP-UA 220 as a communication request destination to the SIP-UA 220 (step S31). Also, here, the SIP server 320 transmits an SIP provisional response (100 Trying) indicating that the communication request has been received and processed to the SIP-UA 120 (step S32).

  Upon receiving the SIP message (INVITE) transmitted from the SIP server 320, the SIP-UA 220 transmits an SIP message (100 Trying) to the SIP server 320 (step S33). When the SIP-UA 220 starts calling the telephone terminal 210 based on the communication request, the SIP-UA 220 transmits a SIP message (180 Ringing) indicating that the calling is in progress to the SIP server 320 (step S34). The SIP server 320 transfers the SIP message (180 Ringing) transmitted from the SIP-UA 220 to the SIP-UA 120 (step S35).

  When the user of the SIP-UA 220 picks up the handset of the telephone terminal 210 and goes off hook, for example, the SIP-UA 220 transmits a SIP message (200 OK) to the SIP server 320 (step S36). The SIP server 320 transfers the SIP message (200 OK) received from the SIP-UA 220 to the SIP-UA 120 (step S37). Here, the address registration unit 128 of the SIP-UA 120 reads the IP address (10.2.2.2) of the SIP-UA 220 included in the header of the SIP message (200 OK) received in step S37, and stores the address information. Stored in the unit 122.

  Upon receiving the SIP message (200 OK) transferred from the SIP server 320, the SIP-UA 120 transmits a SIP message (ACK) to the SIP server 320 (step S38), and the SIP server 320 received from the SIP-UA 120. The SIP message (ACK) is transferred to the SIP-UA 220 (step S39). Here, the address information storage unit of the SIP-UA 220 stores the telephone number (0611111111) and IP address (10.1.1.1) of the SIP-UA 120 included in the header of the SIP message (ACK) received in step S39. Is memorized. Then, the SIP-UA 120 and the SIP-UA 220 start IP telephone communication by the RTP media session (step S40).

  Returning to FIG. 4, when the first SIP communication control unit 126 starts communication processing based on SIP in step S <b> 4, the address registration unit 128 has a free space for storing address information in the storage capacity of the address information storage unit 122. It is determined whether or not (step S5). Here, when the address registration unit 128 determines that there is no space in the address information storage unit 122 (step S5: NO), the registration date and time is determined to be old among the address information stored in the address information storage unit 122. Of the number of pieces of address information, address information with a small number of transmissions is retrieved from the address information storage unit 122 and read out (step S6). Then, the address registration unit 128 deletes the read address information from the address information storage unit 122 (step S7). As described above, since the address information stored in the address information storage unit 122 may be a large amount of data, when there is no more space for adding address information to the storage capacity, the old address information is deleted and a new one is deleted. The address information including the telephone number used for is stored. As a result, it is possible to store address information that is considered to be frequently used while deleting address information that is not frequently used stored in the address information storage unit 122. Here, the selection condition of the object to be deleted may be arbitrarily changed.

  SIP message received from the SIP-UA 220 by the SIP-UA 120 when the address registration unit 128 determines that there is a free space for storing the address information in the storage capacity of the address information storage unit 122 after step S7 is completed. 200 OK), the telephone number and IP address of the SIP-UA 220 are read (step S8) and stored in the address information storage unit 122 (step S9). Here, the address registration unit 128 can read out the telephone number and the IP address of the SIP-UA 220 on the called side from the Contact attribute in the header part of the SIP message. FIG. 6 is a data example of the SIP message (INVITE), and the part (a) is the Contact attribute. Here, the data format of the Contact attribute is a format of “Contact: <sip: phone number @ IP address>”. When communication between the SIP-UA 120 and the SIP-UA 220 is established by SIP communication via the SIP server 320, the telephone communication unit 129 starts IP telephone communication using the RTP media session (step S20).

  On the other hand, in step S3, the determination unit 124 determines that the address information storing the corresponding IP address that matches the communication request destination telephone number transmitted in step S1 is stored in the address information storage unit 122. If it is determined (step S3: match), the determination unit 124 reads the matched address information. The determination unit 124 compares the registration date / time included in the read address information with the current date / time, calculates the elapsed time from the registration date / time to the present (step S10), and whether the elapsed time exceeds a predetermined period. It is determined whether or not (step S11).

  If the determination unit 124 determines that the elapsed time exceeds a predetermined period (step S11: exceeded), the address registration unit 128 determines that the elapsed time exceeds a predetermined period. The information is deleted from the address information storage unit 122 (step S12). In step S 4, the first SIP communication control unit 126 makes a communication request via the SIP server 320.

  On the other hand, if the determination unit 124 determines in step S11 that the elapsed time does not exceed the predetermined period (step S11: not exceeded), the second SIP communication control unit 127 sets the communication request destination telephone number. Read the corresponding IP address (10.2.2.2). The second SIP communication control unit 127 transmits a communication request with the read IP address as the destination, and determines whether or not IP communication can be performed (step S13). If the second SIP communication control unit 127 determines that there is no response to the communication request addressed to the IP address (10.2.2.2) and IP communication cannot be performed (step S13: impossible), the connection request times out. (Step S14), the process proceeds to Step S4.

  On the other hand, when the second SIP communication control unit 127 receives the response to the transmitted communication request and determines that IP communication can be performed in S13 (step S13: Yes), the SIP-UA 120 -A communication request is transmitted to UA220, and the communication process based on SIP is performed (step S15). Here, the second SIP communication control unit 127 of the SIP-UA 120 transmits a SIP message (INVITE) of a communication request addressed to the SIP-UA 220 and receives a SIP message that is a response from the SIP-UA 220 ( Step S16).

  Sequence example of the case where the SIP message of the response received by the SIP-UA 120 from the SIP-UA 220 is a SIP message (100 Trying) indicating that the SIP-UA 220 has normally received the communication request (Step S16: 100 Trying). As shown in FIG. When the second SIP communication control unit 127 reads out the IP address (10.2.2.2) corresponding to the telephone number of the communication destination from the address information storage unit 122 (step S50), the IP of the read SIP-UA 220 is read out. A SIP message (INVITE) of a communication request with the address as the communication destination is transmitted to the SIP-UA 220 (step S51).

  The SIP-UA 220 transmits an SIP message (100 Trying) indicating that the communication request has been received to the SIP-UA 120 (step S52). Further, when the SIP-UA 220 starts calling the telephone terminal 210, the SIP-UA 220 transmits a SIP message (180 Ringing) to the SIP server 320 (step S53). When the user of the SIP-UA 220 picks up the handset of the telephone terminal 210, for example, the SIP-UA 220 transmits a SIP message (200 OK) to the SIP-UA 120 (step S54). Upon receiving the SIP message (200 OK), the SIP-UA 120 transmits a SIP message (ACK) to the SIP-UA 220 (Step S55). Then, the SIP-UA 120 and the SIP-UA 220 start IP telephone communication by the RTP media session (step S56).

  Returning to FIG. 4, when the communication control unit 123 receives the response SIP message (200 OK) transmitted from the SIP server 320, the address registration unit 128 counts up the number of outgoing calls stored in the address information storage unit 122. (Step S17). Then, when the communication control unit 123 establishes a communication connection with the SIP-UA 220 based on SIP communication, the telephone communication unit 129 starts IP telephone communication by the RTP media session (step S20).

  On the other hand, in step S16, the SIP message received by the SIP-UA 120 from the SIP-UA 220 is a SIP message (4xx client error) indicating that the SIP-UA 220 has not normally received a communication request (step S16: A sequence example of (4xx Client) is shown in FIG. When an SIP message (4xx client error) indicating an error is received from the SIP-UA 220 in response to the SIP message (INVITE) (step S60) of the communication request transmitted from the SIP-UA 120 (step S61), the SIP-UA 120 Then, a SIP message (SIP CANCEL) indicating that the SIP communication is canceled is transmitted to the SIP-UA 220 (step S62).

  Returning to FIG. 4, the second SIP communication control unit 127 transmits a SIP message (SIP CANCEL) indicating that SIP communication is canceled to the SIP-UA 220 to explicitly release the session (step S <b> 18). When the address information including the IP address to which the address registration unit 128 does not respond is deleted from the address information storage unit 122 (step S19), the process proceeds to step S4.

  Thus, according to the present embodiment, when the IP telephone communication is performed via the SIP server 320 by the first SIP communication control unit 126 of the SIP-UA 120, the telephone number of the communication destination is the address information storage unit 122. The subsequent SIP communication can be performed directly between the SIP-UA 120 and the SIP-UA 220 without going through the SIP server 320 based on the IP address stored in the address information storage unit 122. Thereby, it is possible to suppress SIP communication including an address resolution request transmitted from the SIP-UA 120, reduce the processing load on the SIP server 320, and prevent a control delay. Further, even when the SIP server 320 fails and address resolution cannot be performed, communication with the IP address stored in the address information storage unit 122 as the destination can be performed, and the availability is improved. Further, by reducing the processing load of the SIP server 320 in this way, it is possible to suppress the equipment amount and reduce the equipment cost associated with the call, reduce the call charge, and increase the user merit.

  Further, according to the present embodiment, the address information stored in the address information storage unit 122 is deleted when a certain period has elapsed from the registration date and time, and the address information is newly stored via the SIP server 320. Since the IP address acquired by performing the SIP communication is stored in the address information storage unit 122, it is possible to rewrite the address information stored in the address information storage unit 122 with new information at regular intervals. Become.

  In addition, according to the present embodiment, when SIP communication is directly performed from the SIP-UA 120 to the SIP-UA 220 and a communication error occurs, the address information is deleted, and the SIP communication via the SIP server 320 is newly performed. Since the acquired IP address is stored in the address information storage unit 122, the IP address and port number can be rewritten or relayed by a NAT (Network Address Translation) or NAPT (Network Address Port Translation) function in the network. Even when the device is transferred or abolished, the latest IP address is obtained via the SIP server 320 for communication, and the information stored in the address information storage unit 122 is rewritten with the latest information. It becomes possible.

<Second Embodiment>
In the first embodiment, the SIP-UA 120 such as TA that connects the telephone terminal 110 and the line termination device 140 is provided with the functions of the address information storage unit 122 and the communication control unit 123. The function may be provided in the line terminating device 140, the subscriber edge router 310, or the like. In the second embodiment, an IP telephone communication system when the line terminating device 140 is provided with this function will be described. FIG. 9 is a block diagram showing the configuration of the line termination device 140 according to the second embodiment of the present invention. The line termination device 140 includes a communication module 141 connected to the SIP-UA 120, a communication module 150 connected to the subscriber edge router 310, an address information storage unit 142, and a communication control unit 143. The address information storage unit 142 and the communication control unit 143 have the same functions as the address information storage unit 122 and the communication control unit 123 included in the SIP-UA 120 in the first embodiment.

  FIG. 10 is a diagram illustrating an operation example of the IP telephone communication system 1 according to the second embodiment. First, when the telephone terminal 110 accepts a telephone number input from the user (step S101), the SIP-UA 120 transmits a communication request addressed to the SIP server 320 (step S102). The line termination device 140 acquires a communication request transmitted from the SIP-UA 120 to the SIP server 320 (step S103), and the address registration unit 148 stores the communication destination telephone number included in the communication request in the address information storage unit 142. Store (step S104). Hereinafter, the processing from step S105 to step S110 by the line terminating device 140 is the same as the processing from step S3 to step S9 by the SIP-UA 120 in the first embodiment. FIG. 11 is a diagram illustrating a sequence of SIP communication performed by the SIP-UA 120 via the line terminating device 140 and the SIP server 320.

  The processing in step S111 to step S113 in FIG. 10 is the same as the processing in step S10 to step S12 in the first embodiment, but in step S112, the determination unit 124 causes the elapsed time to exceed a predetermined period. If it is determined that it is not present (step S112: not exceeded), the communication control unit 123 redirects a communication request having the IP address of the SIP-UA 220 as a communication destination to the SIP-UA 120 (step S114). The SIP-UA 120 transmits the redirected communication request to the SIP-UA 220 (step S115). FIG. 12 is a diagram illustrating a sequence example when the line termination device 140 redirects a communication request. Hereinafter, the processing after step S116 in FIG. 10 is the same as the processing after step S16 in the first embodiment.

  Here, when the line termination device 140 is redirected in this way and the SIP-UA 120 and the SIP-UA 220 perform SIP communication in P2P, address spoofing can be performed by rewriting the from message in the SIP header on the terminal side, etc. Sex is conceivable. As a countermeasure, for example, configuration information such as a telephone number and IP address set in SIP-UA such as TA is configured not to be rewritten unless it is based on control information from the carrier IP network. Alternatively, as a countermeasure, the setting information stored in the SIP-UA can be rewritten by the user, but it must be registered on the carrier IP network side so that it cannot participate in the IP telephone communication system, and the validity of the SIP-UA that transmits INVITE is verified. It is configured so that it can be confirmed on the carrier IP network side.

<Third Embodiment>
When a plurality of carrier IP networks exist in the network of the IP telephone communication system 1 and IP telephone communication is performed across a plurality of carrier IP networks, the carrier IP network is connected to another carrier IP network. A large number of SBCs (Session Border Controllers) may include the functional units of the address information storage unit 142 and the communication control unit 143 included in the line termination device 140 described in the second embodiment. FIG. 13 is a diagram illustrating an example in which the A communication carrier network 1300 and the B communication carrier network 1400 are connected by the SBC 1350 and the SBC 1450 respectively provided.

  SBC is a device installed at the boundary between different IP telephone networks. In general, SBC absorbs and hides the differences between IP telephone networks that do not match the IP telephone network address system and management conditions, and is not aware of the other party's network. An IP telephone network can be operated. Specific functions of the SBC include an address translation function (NAT (NAPT) function, ALG (Application level Gateway) function), and a firewall function. The NAT (NAPT) function is a function for converting the IP address and port number of the IP layer. Here, the IP address and port number of the SIP proxy are statically stored in advance in the NAT table, and the IP addresses and port numbers of other terminals are dynamically changed. The ALG function converts the IP address and port number described in the payload of the IP packet in the application layer above the IP layer. In SIP, an IP address and a port number described in the Contact attribute of the SIP message in the payload (message body after the header) of the IP packet are converted.

  In addition, considering number portability and the like, even when another network user returns to the own network, depending on the implementation, SIP communication based on the address information stored in the address information storage unit 142 is via the SBC, and the load on the SBC is reduced. Concerned. For this reason, as shown in the first and second embodiments, the registration date and time is recorded for each stored address information, and the address information is deleted when a predetermined time is exceeded. .

  As shown in FIG. 13, the SIP-UA 1120 transmits an INVITE packet destined for the telephone terminal 1210 to the SIP proxy 1320 (step S160). When the SIP proxy 1320 receives an INVITE packet destined for a telephone number that is not managed by the proxy, the SIP proxy 1320 inquires of the number management DB about the IP address corresponding to the telephone number (steps S162 and S161).

  The SIP proxy 1320 transmits an INVITE packet destined for the IP address read in step S161 to the SBC 1450 (step S163). At this time, the SBC 1350 performs NAT conversion of the transmitted IP packet (step S164). In addition, the SBC 1350 converts the IP address and port number described in the IP payload on the originating side of the IP packet and stores them in the ALG table (step S165).

  The SBC 1450 performs NAT conversion on the INVITE packet transmitted via the SBC 1350 (step S166) and transfers the packet to the SIP proxy 1420. The SIP proxy 1420 transmits the INVITE packet to the destination SIP-UA 1220 of the received INVITE packet (step S168). The SIP-UA 1220 transmits a response to the received INVITE packet (step S169). The response packet transmitted from the SIP-UA 1220 is subjected to NAT processing and ALG processing by the SBC 1450 (step S170).

  After the session is established, the SIP-UA 1120 transmits the RTP packet to the Constant attribute that has been ALG converted by the B communication carrier network 1400 (transmission destination: 10.56.1.2: 5666) (step S171). When the SBC 1450 receives the RTP packet transmitted from the SIP-UA 1120, the SBC 1450 refers to the IP address and port number of the SIP-UA 1220 managed in its own ALG table, and uses the SIP-UA 1220 as the destination IP address and port number. The RTP packet is transmitted to (step S172). Similarly, the RTP packet that the SIP-UA 1220 transmits to the SIP-UA 1120 also transmits the RTP packet to the Constant attribute that is ALG-converted by the A communication carrier network 1300 to perform RTP communication.

  Note that a program for realizing the function of the processing unit in the present invention is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed, thereby executing IP telephone communication. You may go. The “computer system” here includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

It is a figure which shows the structure of the IP telephone communication system by the 1st Embodiment of this invention. It is a figure which shows the terminal structure of SIP-UA120 by the 1st Embodiment of this invention. It is a figure which shows the data example of the address information memorize | stored in the address information storage part by the 1st Embodiment of this invention. It is a figure which shows the operation example of the IP telephone communication system by the 1st Embodiment of this invention. It is a sequence diagram which shows the SIP communication of the IP telephone communication system by the 1st Embodiment of this invention. It is a figure which shows the example of the SIP header by the 1st Embodiment of this invention. It is a sequence diagram which shows the SIP communication of the IP telephone communication system by the 1st Embodiment of this invention. It is a sequence diagram which shows the SIP communication of the IP telephone communication system by the 1st Embodiment of this invention. It is a figure which shows the terminal structure of the line termination apparatus by the 2nd Embodiment of this invention. It is a figure which shows the operation example of the IP telephone communication system by the 2nd Embodiment of this invention. It is a sequence diagram which shows SIP communication of the IP telephone communication system by the 2nd Embodiment of this invention. It is a sequence diagram which shows SIP communication of the IP telephone communication system by the 2nd Embodiment of this invention. It is a figure which shows the example which applies the function by the 2nd Embodiment of this invention to SBC.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 IP telephone communication system 100 Subscriber network 110 Telephone terminal 120 SIP-UA
121 A / D signal converter 122 Address information storage unit 123 Communication control unit 124 Judgment unit 125 SIP communication control unit 126 First SIP communication control unit 127 Second SIP communication control unit 128 Address registration unit 129 Telephone communication unit 130 Communication Module 140 Line termination device 141 Communication module 142 Address information storage unit 143 Communication control unit 144 Judgment unit 145 SIP communication control unit 146 First SIP communication control unit 147 Second SIP communication control unit 148 Address registration unit 150 Communication module 200 Subscription Network 210 telephone terminal 220 SIP-UA
240 Line Terminator 300 Carrier IP Network 310 Subscriber Edge Router 320 SIP Server 330 Subscriber Edge Router 1100 Subscriber Network 1110 Telephone Terminal 1120 SIP-UA
1200 subscriber network 1210 telephone terminal 1220 SIP-UA
1300 A carrier network 1320 SIP proxy 1350 SBC
1420 SIP proxy 1400 B carrier network 1450 SBC

Claims (6)

A telephone number and an IP address of a communication destination IP telephone communication apparatus which is a communication destination by IP telephone communication are stored in association with each other, a communication request based on SIP having the telephone number as a communication destination is received, and the received communication An IP telephone communication device connected via a network to a SIP server that transmits a request with the IP address corresponding to the telephone number as a communication destination and relays SIP communication,
A storage unit for storing the telephone number and the IP address in association with each other;
A first SIP communication control unit configured to transmit the communication request including a communication destination telephone number to the SIP server, and to communicate with the communication destination IP telephone communication device via the SIP server;
An address registration unit for storing the telephone number and the IP address corresponding to the telephone number received by the first SIP communication control unit from the SIP server in the storage unit;
An input section for inputting the telephone number of the communication destination;
A determination unit that determines whether or not an IP address corresponding to the telephone number input to the input unit is stored in the storage unit;
When the determination unit determines that the IP address corresponding to the telephone number is stored in the storage unit, the IP address corresponding to the telephone number is read from the storage unit, and the read IP address is the communication destination A second SIP communication control unit for communicating with the communication destination IP telephone communication device by transmitting a communication request as:
An IP telephone communication apparatus comprising: The storage unit stores the date and time when the telephone number and the IP address were stored by the address registration unit,
The determination unit compares the date and time when the IP address corresponding to the telephone number input to the input unit is stored in the storage unit with the current date and time, and whether or not a predetermined period has elapsed Determine whether
The said 1st SIP communication control part transmits the said communication request to the said SIP server, when it determines with the said determination part having passed the said predetermined period. IP telephone communication device. The determination unit determines whether or not a response to the communication request transmitted from the second SIP communication control unit to the communication destination IP telephone communication device indicates a communication error;
The said 1st SIP communication control part transmits the said communication request to the said SIP server, when it determines with the said response showing a communication error. The Claim 1 or Claim 2 characterized by the above-mentioned. IP telephone communication device. The non-volatile memory in which the stored telephone number and the IP address are retained even when the supply of power is interrupted is applied to the storage unit. 2. The IP telephone communication apparatus according to claim 1. An IP telephone communication apparatus that transmits a communication request based on SIP having the telephone number of the input destination IP telephone communication apparatus as a communication destination, and the telephone number and IP address of the communication destination IP telephone communication apparatus are associated with each other. A SIP server that receives a communication request based on SIP that is stored and that has the telephone number as a communication destination, transmits the received communication request using the IP address corresponding to the telephone number as a communication destination, and relays SIP communication; An IP telephone communication relay device connected to
A storage unit for storing the telephone number and the IP address in association with each other;
First SIP communication control for transmitting the communication request including the telephone number of the communication destination received from the IP telephone communication device to the SIP server and communicating with the communication destination IP telephone communication device via the SIP server And
An address registration unit for storing the telephone number and the IP address corresponding to the telephone number transmitted from the SIP server in the storage unit;
A determination unit that determines whether an IP address corresponding to the communication destination telephone number of the communication request received from the IP telephone communication device is stored in the storage unit;
When the determination unit determines that the IP address corresponding to the telephone number is stored in the storage unit, the IP address corresponding to the telephone number is read from the storage unit, and the read IP address is the communication destination A second SIP communication control unit for communicating with the communication destination IP telephone communication device by transmitting a communication request as:
An IP telephone communication relay device comprising: A telephone number and an IP address of a communication destination IP telephone communication apparatus which is a communication destination by IP telephone communication are stored in association with each other, a communication request based on SIP having the telephone number as a communication destination is received, and the received communication A request is transmitted via the network to a SIP server that transmits the IP address corresponding to the telephone number as a communication destination and relays SIP communication, and the telephone number and the IP address are stored in association with each other An IP telephone communication method by an IP telephone communication apparatus comprising a unit,
A first SIP communication control unit transmits the communication request including a communication destination telephone number to the SIP server, and communicates with the communication destination IP telephone communication device via the SIP server;
An address registration unit storing the telephone number and the IP address corresponding to the telephone number received by the first SIP communication control unit from the SIP server in the storage unit;
A step in which the telephone number of the communication destination is input to the input unit;
A step of determining whether or not an IP address corresponding to the telephone number input to the input unit is stored in the storage unit;
When the second SIP communication control unit determines that the determination unit stores an IP address corresponding to the telephone number in the storage unit, the second SIP communication control unit receives the IP address corresponding to the telephone number from the storage unit. Reading and communicating a communication request with the read IP address as a communication destination to communicate with the communication destination IP telephone communication device;
An IP telephone communication method comprising:

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