JP2008236470A - Ip telephone terminal and ip telephone system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish a call between terminals even if a call agent (hereinafter, to be referred to as CA) stops. <P>SOLUTION: An IP telephone terminal 20-1 inputs telephone number of a callee IP telephone terminal 20-2, and transmits a first connection request, including a telephone number to CA10-1 (processing 1001). When an IP address corresponding to the telephone number contained in the first connection request from the CA10-1 is received, the received IP address is stored in association with a telephone number. Via the CA10-1, a call connection is established with the IP telephone terminal 20-2. The IP telephone terminal 20-1, if there is no response coming from the CA10-1 after transmitting the first connection request, searches for a memory based on the inputted telephone number for acquiring a corresponding IP address (processing 1005). In accordance with the IP address acquired, a second connection request is transmitted directly to the IP telephone terminal 20-2 (processing 1008). Also a call connection is established with the IP telephone terminal 20-2 without the intervention of the CA10-1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an IP telephone terminal and an IP telephone system, and more particularly, an IP telephone terminal that establishes a call even when a call agent malfunctions by improving the functionality of the IP telephone terminal. The present invention relates to an IP telephone terminal and an IP telephone system that store telephone number information and IP address information of an IP telephone terminal in association with each other and establish a call independently by the IP telephone terminal using the telephone number information and the IP address information.

With the development of IP (Internet Protocol) technology, IP technology has been introduced into public telephone networks, and means for communicating voice signals using VoIP (Voice over IP) technology has been established. In applying the IP technology to the public telephone network, it is desired that a telephone call by a person is realized by inputting a telephone number of a call destination to a telephone as is conventionally done. On the other hand, in communication using the IP technology, an IP address for specifying individual devices in a network is used. Therefore, when applying the IP technology to the public telephone network, a server called a call agent, which has a database that associates telephone numbers with IP addresses, and controls telephone calls between telephone terminals is used.
The database that associates the telephone number and IP address in the call agent is created, for example, by registering the telephone number and the IP address from the telephone to the server when the telephone is connected to the network. Each phone needs to have an individual IP address. For example, in a DHCP (Dynamic Host Configuration Protocol) server, the use status of the IP address is centrally managed, and each device is managed. This is realized by assigning an IP address to
A system is disclosed in which a telephone terminal is associated with an IP address of a voice transmission UDP channel at the time of call connection (see, for example, Patent Document 1). In this system, one IP address can be used by a plurality of telephone terminals, and the shortage of IP addresses is addressed. Further, it is disclosed that a telephone terminal is not registered in a DNS server and can be used for emergency communication.

Japanese Patent No. 3436471

In the above-described form, the IP technology is applied to the public telephone network. However, for example, when a call agent breaks down or becomes congested due to an increase in communication traffic, a call may not be made.
In an IP public telephone network, it is necessary to secure communication connectivity as much as possible. Therefore, it is a problem to reduce as much as possible the possibility of making a call impossible due to a failure or congestion of a call agent having a function of associating a telephone number with an IP address.
The present invention has been made in view of the above points, and an object thereof is to provide an IP telephone terminal and an IP telephone system that enable a call between end users even when the system and a central server (for example, a call agent) are stopped. To do. Another object of the present invention is to prevent a call from becoming impossible due to the concentration of lines on a call agent or the like.
In the present invention, even when a call agent responsible for communication control in an IP public telephone network has malfunctioned due to a failure or congestion, if the telephone number and the IP address can be accurately handled, the IP telephone terminal is unique. One of the purposes is to establish a call. Another object of the present invention is to avoid erroneous connection of a telephone call when the telephone number and the IP address are not accurately associated.

In order to solve the above-described problem, in the present invention, the IP telephone terminal has a function of detecting an abnormal operation of the call agent in communication with the call agent, and when the call agent has been operating normally after making a call in the past. A means for extracting the correspondence between the telephone number of the connection destination and the IP address obtained in the above and storing it in a database is installed.
The present invention, for example, by performing communication according to a call control protocol between IP telephone terminals via a call agent in an IP network having two or more IP telephone terminals and one or a plurality of call agents. In an IP phone terminal that establishes a call,
In the IP telephone terminal, the correspondence information between the telephone number and the IP address of the other IP telephone terminal acquired during communication with the other IP telephone terminal or the call agent is stored as a database as needed.
When communication from the IP phone terminal to the call agent becomes impossible and communication of the call control protocol between IP phone terminals becomes impossible via the call agent,
In the IP phone terminal, it independently determines whether communication to the call agent is possible. If communication is not possible, the IP address of the phone number desired to be called is searched from its own database, and if found, By trying to communicate with the IP address directly using the call control protocol, it is possible to make a call even when communication to the call agent is impossible.
When an incoming call is received, the IP phone terminal on the receiving side collates the called telephone number contained in the transmission data with its own telephone number. If the matching results match, the call is established, If the result of the check is inconsistent, the incoming call is rejected and the call is completed.

According to the first solution of the present invention,
The IP for calling between the IP telephone terminals in an IP network having a plurality of IP telephone terminals and a call agent in which a telephone number of the IP telephone terminal and an IP address of the IP telephone terminal are stored correspondingly A phone terminal,
A memory in which a telephone number of another IP telephone terminal and the IP address of the IP telephone terminal are stored correspondingly;
A control unit that performs call connection processing;
With
The control unit inputs a telephone number of a desired destination IP telephone terminal in the first call connection, and transmits a first connection request including the telephone number to the call agent according to a predetermined IP address. And
When the destination IP telephone terminal is called by the call agent according to the first connection request and receives a call signal notification including an IP address corresponding to the telephone number included in the first connection request, the call agent receives Storing the received IP address in the memory corresponding to the telephone number, and establishing a first call connection with the destination IP telephone terminal via the call agent;
In the second call connection after the first call connection, the telephone number of the destination IP telephone terminal is input, and a second connection request including the telephone number is sent to the call agent according to a predetermined IP address. Send
When there is no response from the call agent within a predetermined time due to a failure or congestion of the call agent or a system failure, the memory is searched based on the input telephone number of the destination IP telephone terminal and the corresponding IP address Get
The IP telephone which transmits a third connection request to the destination IP telephone terminal according to the acquired IP address and establishes a second call connection with the destination IP telephone terminal without going through the call agent A terminal is provided.

According to the second solution of the present invention,
A first IP telephone terminal;
A second IP telephone terminal;
A call agent in which the telephone numbers of the first and second IP telephone terminals and the addresses of the IP telephone terminals are stored correspondingly;
The first and second IP telephone terminals are respectively
A memory in which a telephone number of another IP telephone terminal and the IP address of the IP telephone terminal are stored correspondingly;
A control unit that performs call connection processing;
With
The control unit of the first IP telephone terminal is
In the first call connection, the telephone number of the second IP telephone terminal is input, and a first connection request including the telephone number is transmitted to the call agent according to a predetermined IP address.
When the second IP telephone terminal is called by the call agent according to the first connection request and receives a call signal notification including an IP address corresponding to the telephone number included in the first connection request from the call agent, Storing the received IP address in the memory corresponding to the telephone number, and establishing a first call connection with the second IP telephone terminal via the call agent;
In the second call connection after the first call connection, the telephone number of the second IP telephone terminal is input, and a second connection request including the telephone number is sent to the call agent according to a predetermined IP address. To
If there is no response from the call agent within a predetermined time due to a failure or congestion of the call agent or a system failure, the memory is searched based on the input telephone number of the second IP telephone terminal and the corresponding IP Get the address,
Sending a third connection request to the second IP telephone terminal according to the acquired IP address;
An IP telephone system is provided in which a second call connection is established between the first IP telephone terminal and the second IP telephone terminal.

According to the present invention, it is possible to provide an IP telephone terminal and an IP telephone system that enable a call between end users even when the system and a central server (for example, a call agent) are stopped. In addition, according to the present invention, it is possible to prevent a call from becoming impossible due to the concentration of lines on a call agent or the like.
According to the present invention, even when a call agent that plays a role of communication control in an IP public telephone network has malfunctioned due to a failure or congestion, if the telephone number and the IP address can be accurately handled, the IP telephone terminal You can establish your own call. Further, according to the present invention, when the telephone number and the IP address are not correctly associated, it is possible to avoid erroneous connection of the call.

(System configuration)
FIG. 1 is an overall configuration diagram of an IP telephone network according to the present embodiment.
The IP network 101 includes, for example, n (n is an integer of 2 or more) IP telephone terminals (IP telephone terminal 20-1, IP telephone terminal 20-2, IP telephone terminal 20-3,..., IP telephone terminal 10- n), m (n is an integer equal to or greater than 1) call agents (call agent 10-1, call agent 10-2,..., call agent 10-m), and DNS (Domain Name System) server 109. .
The IP telephone system according to the present embodiment is, for example, similar to the existing IP telephone system, all IP telephone terminals (IP telephone terminal 20-1, IP telephone terminal 20-2, IP telephone terminal 20-3,... An IP address is assigned by the DNS server 109 to the IP telephone terminal 10-n) and all the call agents (call agent 10-1, call agent 10-2,..., Call agent 10-m). When the IP telephone terminal (20-1 to 10-n) is restarted, the IP address used so far is discarded, and another IP address is newly communicated with the DNS server 109. get. That is, the IP addresses of the IP telephone terminals (20-1 to 10-n) are variable. The IP address may be fixed. On the other hand, the call agent (10-1 to 10-m) may set a fixed IP address so as to always allow access from the IP telephone terminal (20-1 to 10-n).
In the present embodiment, similar to the existing telephone network, each IP telephone terminal (20-1 to 10-n) is set with a unique telephone number. Use.
In the IP telephone system according to the present embodiment, when communication between the IP telephone terminal 20 and the call agent 10 is possible, for example, according to a call control protocol such as SIP (Session Initiation Protocol) defined by RFC3261. A call between IP telephones can be established. The protocol is H.264 other than SIP. An appropriate call control protocol such as H.323 or a protocol for voice communication may be used.
When communication between the IP telephone terminal 20 and the call agent 10 is impossible due to a failure or congestion of the call agent 10, a call is realized by a method described in detail below.

FIG. 2 is an internal configuration diagram of the IP telephone terminal 20-1.
The IP telephone terminal 20-1 includes a control unit 201, a memory 202, a telephone number detection unit 203, a hooking detection unit 204, a line connection unit 205, an analog / digital data conversion unit 206, a microphone unit 207, and a speaker unit 208.
The control unit 201 generates and analyzes instructions and IP packets for other constituent blocks. The control unit 201 controls call connection. The memory 202 stores a telephone number and an IP address correspondingly. The telephone number detection unit 203 detects a telephone number input by a push button or the like. The hooking detection unit 204 detects on-hook and off-hook. The line connection unit 205 transmits the IP packet created by the control unit 201 to the IP network 101, and transmits the IP packet received from the IP network 101 to the control unit 201. The analog / digital data conversion unit 206 converts the digital data generated by the control unit 201 into analog data and outputs the analog data to the speaker 208. In addition, the control unit 201 converts analog data input from the microphone 207 into digital data and transfers the digital data to the control unit 201. The IP telephone terminals 20-2 to 20-n have the same configuration as the IP telephone terminal 20-1.
IP telephone terminal 20 in the present embodiment may be configured by a general telephone terminal and an IP telephone modem. In the following description, it is simply referred to as an IP telephone terminal.
FIG. 14 shows an internal configuration diagram of IP telephone terminal 20 in the case where IP telephone modem 1404 and telephone terminal 1401 are configured.
The IP telephone modem 1404 includes a control unit 201, a memory 202, a telephone number detection unit 203, a hooking detection unit 204, a line connection unit 205, an analog / digital data conversion unit 206, and a telephone terminal line connection unit 1403. The analog / digital data conversion unit 206 converts digital data such as call control and voice generated by the control unit 201 into analog data. Also, analog data from the telephone line connection unit 1403 is converted into digital data and transmitted to the control unit 201. Analog data such as call control and voice is communicated with the telephone terminal 1401 from the telephone line connection unit 1403 through, for example, the telephone line 1402. Other configurations are the same as those in FIG. The telephone terminal 1401 includes, for example, portions corresponding to the above-described microphone unit, speaker unit, and hooking detection unit.

FIG. 13 is an internal configuration diagram of the memory 202 of the IP telephone terminal.
The memory 202 has an area 1301 for storing its own telephone number, an area 1302 for storing its own IP address, an area 1303 for storing the IP address of the call agent, and the telephone number of the destination IP telephone terminal that has made a call in the past It has a database 301 for storing correspondence of IP addresses. In FIG. 13, the internal configuration of the memory of IP telephone terminal 20-1 is shown as an example, and “00-1234-5678”, which is the telephone number of IP telephone terminal 20-1, is assigned to own telephone number 1301. “AA.AA.AA” which is the IP address of the IP telephone terminal 20-1 assigned in advance to the IP address 1302, and the communication partner of the IP telephone terminal 20-1 to the IP address 1303 of the call agent The predetermined IP address of the call agent 10-1 “100.100.1.30” is stored.
FIG. 3 is an internal configuration diagram of the database 301 for storing the correspondence between the telephone number of the destination IP telephone terminal and the IP address.
The database 301 stores a telephone number and an IP address of one IP telephone terminal that is a call partner in association with each item number, for example. The item numbers are, for example, from item number 1 (302) to item number r (304), and can store a maximum of telephone numbers and IP addresses for r IP telephone terminals.

  FIG. 3 shows a database in the memory 202 of the IP telephone terminal 20-1 as an example. In the item number 1 (302), for example, information of the IP telephone terminal 20-2 is stored, and a telephone number storage area 305 is stored. Stores the telephone number “01-1223-3333” of the IP telephone terminal 20-2. The IP address storage area 308 stores the IP address “BB.BB.BB” of the IP telephone terminal 2. The item number 2 (303) is, for example, an item number indicating the information of the IP telephone terminal 20-3. The telephone number storage area 306 includes the telephone number "06-5555-4444" of the IP telephone terminal 20-3, In the IP address storage area 309, the IP address “CC.CC.C.C” of the IP telephone terminal 3 is stored. The item number r (304) is, for example, an item number indicating the information of the IP telephone terminal 10-n. The telephone number storage area 307 stores the telephone number “09-9999-9999” of the IP telephone terminal 10-n, the IP address The storage area 310 stores the IP address “DD.DD.D.D” of the IP telephone terminal 10-n. These pieces of information are stored by the control unit 201 at the time of call connection when the CA 10 is operating normally, as will be described later.

(Calling party processing)
4, 5 and 6 are examples of flowcharts showing the operation from the call origination from the IP telephone terminal to the establishment of the call.
In this example and the example of the operation flowchart of the terminating IP telephone terminal shown in FIG. 7, SIP is used as a call control protocol, and “INVITE”, “ACK”, and “BYE” are SIP request messages. “180 Ringing” and “200 OK” are responses to the SIP request message.
For example, the control unit 201 of the IP telephone terminal (source IP telephone terminal, first IP telephone terminal) 20-1 first detects an off-hook from the hooking detection unit 204 (process 402) as the operation start (process 401). To do. Then, the telephone number input waiting state is entered, and the telephone number detection unit 203 acquires the telephone number of the input destination (process 403). In this example, it is assumed that the IP telephone terminal 20-2 is the destination and the telephone number of the IP telephone terminal 20-2 is acquired.
Then, the control unit 201 sets the “INVITE” message transmission count counter value x (times) to x = 0 (processing 404), and sets the time counter value y (seconds) after the “INVITE” message transmission to y = 0. Setting is made (process 405). The control unit 201 sends “INVITE” (first and second connection requests) to the CA 10-1 using the IP address stored in the call agent (hereinafter referred to as CA) IP address storage area 1303 in the memory 202. (Process 406). Further, the control unit 201 starts counting y (processing 407) and waits until “180 Ringing” is received from the CA 10-1.
If there is no problem in communication, CA 10-1 transmits “INVITE” received from IP telephone terminal 20-1 to destination IP telephone terminal (destination IP telephone terminal, second IP telephone terminal) 20-2. . The counterpart terminal 20-2 that has received “INVITE” transmits “180 Ringing” (call signal notification) to the CA 10-1, and the CA 10-1 transmits “180 Ringing” to the IP telephone terminal 20-1. “180 Ringing” includes, for example, the IP address of the destination telephone terminal 20-2.
While waiting for reception of “180 Ringing” (process 409), the control unit 201 ends the reception standby and adds 1 to x when y exceeds a preset threshold value b (seconds) (process 408). (Processing 410). When x does not reach the preset threshold value a (times) (No in process 411), y = 0 is set again (process 405), and INVITE is transmitted again to the CA 10-1 (process 406).

On the other hand, if y does not exceed the preset threshold value b (seconds) (process 408), and the control unit 201 receives “180 Ringing” from the CA 10-1 (process 409), the ringing tone from the speaker unit 208 is obtained. Is output (process 418).
The control unit 201 determines that the connection with the CA 10-1 is possible, and thereafter establishes a call by communicating with the partner terminal 20-2 via the CA 10-1 according to a procedure defined by SIP. . Further, when “180 Ringing” is not received and x reaches the preset threshold value a (times) (processing 411), the control unit determines that connection with the CA is impossible, and the destination terminal as described later. Try to establish a call by communicating directly to 20-2.
Moving to FIG. 5, the control unit 201 searches the input terminal number from the counterpart terminal database 301 (process 501). If the search of the input telephone number fails (No in process 502), the control unit 201 determines that the telephone number has not been registered in the database 301 so far, and includes the input telephone number and “180 Ringing” in the database 301. The IP address of the destination telephone terminal 20-2 is newly added (process 505), and the process proceeds to process 507. Further, when the search of the input telephone number is successful (step 502, Yes), the control unit 201 and the IP address corresponding to the input telephone number on the database 301 and the IP of the counterpart terminal 20-2 described in “180 Ringing” are displayed. The address is compared (process 503). If the comparison results are the same (step 504, Yes), the normality of the database so far is confirmed, and the processing proceeds to step 507 without registration or correction in the database. If the comparison results are not the same (No in process 504), the control unit 201 overwrites the IP address of the destination telephone terminal described in “180 Ringing” with the IP address corresponding to the input telephone number in the database 301 ( The processing proceeds to processing 506) and processing 507.

After the database processing is completed, the control unit 201 receives “200 OK” (confirmation notification) from the CA 10-1 as in the existing call establishment processing defined by SIP (processing 507). The IP telephone terminal 20-1 transmits “ACK” to the CA 10-1 as a response “200 OK” (process 508). By transmitting “ACK” from CA 10-1 to the destination telephone terminal, a call is established and voice packet communication is started with the destination telephone terminal (process 509).
When the hooking detection unit 204 detects on-hook (Yes in processing 510), the IP telephone terminal 20-1 transmits “BYE” (end notification) to the CA 10-1 (processing 516). ACK "is received (process 517), the voice packet communication with the partner terminal is terminated (process 518), and the operation of the control unit 201 is terminated (process 519). When “BYE” is received from CA 10-1 (process 511), control unit 201 transmits “ACK” to CA 10-1 (process 512), and the destination telephone terminal receives “ACK” from CA 10-1. Is received, the voice packet communication with the counterpart terminal is completed (step 513). The IP telephone terminal 20-1 ends the operation of the control unit (processing 515) by detecting the on-hook in the hooking detection unit 513 (processing 514).
As described above, the database 301 of the terminal 20 is updated at the time of communication via the CA 10.

Next, returning to FIG. 4, a case where direct call connection communication is performed with the destination telephone terminal 20-2 will be described.
When x reaches the preset threshold value a (times) (process 411), the control unit 201 searches the database 301 for an IP address corresponding to the input telephone number (process 412). For example, when the search for the IP address of the destination terminal 20-2 fails because the IP address is not registered (No in process 413), the control unit 201 indicates that the speaker unit 208 cannot make a call. A message is output (process 414), and the operation of the control unit 201 is terminated (process 415).
On the other hand, if the IP address search is successful (step 413, Yes), the control unit 201 sets the “INVITE” message transmission count counter value x ′ (times) to x ′ = 0 (step 601). The time counter value y ′ (second) after the “message” is set as y ′ = 0 (process 602). Thereafter, IP telephone terminal 20-1 communicates with counterpart terminal 20-2 instead of CA 10-1.
The control unit 201 transmits “INVITE” (third connection request) to the destination telephone terminal 20-2 (processing 603). The control unit 201 starts counting y ′ (process 604) and waits until a telephone number mismatch message 1205 or “180 Ringing” is received from the counterpart terminal 20-2.
While waiting for reception of the telephone number mismatch message 1205 and “180 Ringing” (processing 606 and processing 607), if y ′ exceeds a preset threshold value b ′ (seconds) (processing 605, Yes), the reception waiting is terminated. Then, 1 is added to x ′ (process 608). If x ′ has not reached the preset threshold value a ′ (times) (No in process 609), y ′ = 0 is set (process 602), and INVITE is transmitted to the destination telephone terminal 20-2 again. (Process 603). When y ′ does not exceed the preset threshold value b ′ (seconds) (No in process 605) and the telephone number mismatch message 1205 is received from the destination terminal 20-2 (Yes in process 606), x When “has reached the preset threshold value a” (times) (step 609, Yes), the control unit 201 determines that a call to the partner terminal 20-2 cannot be established, and the speaker unit 208 A message indicating that the telephone call is impossible is output (process 610), and the operation is terminated (process 611).
When y ′ does not exceed the preset threshold value b ′ (seconds) (No in process 605) and “180 Ringing” is received from the destination telephone terminal 20-2 (Yes in process 607), the control unit 201 Determines that it is possible to establish a call to the destination telephone terminal 20-2, and proceeds to processing 612.

Thereafter, when the control unit 201 receives “200 OK” from the destination telephone terminal 20-2 in accordance with the procedure stipulated by SIP (Process 612), it transmits “ACK” to the destination telephone terminal 20-2 as a response. (Process 613). By transmitting “ACK” to the destination telephone terminal 20-2, the establishment of the call is completed, and voice packet communication is started with the destination telephone terminal 20-2 (step 614).
When the IP phone terminal 20-1 detects on-hook by the hooking detection unit 204 (step 615, Yes), the control unit 201 transmits “BYE” to the destination phone terminal 20-2 (step 621). “ACK” is received from the destination telephone terminal 20-2 (process 622). By receiving “ACK” (process 622), the voice packet communication with the counterpart terminal 20-2 is terminated (process 623), and the operation of the control unit 201 is terminated (process 624).
When “BYE” is received from the other party telephone terminal 20-2 (process 616), the control unit 201 transmits “ACK” to the other party telephone terminal 20-2 (process 617). When 20-2 receives “ACK”, the communication of the voice packet with the destination telephone terminal 20-2 ends (process 618). The IP telephone terminal 20-1 ends the operation of the control unit by detecting the on-hook in the hooking detection unit 513 (processing 619) (processing 620).

(Called party processing)
In the present embodiment, there is a possibility that the wrong terminal is received when the CA 10-1 is out of order or congested and the IP address of the destination telephone terminal has been changed. In order to solve this, when an incoming call is accepted, the transmitted incoming telephone number and the own telephone number 1301 are collated, and the incoming call is accepted according to the matching, and the call is established, or the incoming call is received. Equipped with a means to reject the call and disconnect the call. Details will be described with reference to FIG.
FIG. 7 is an example of a flowchart showing an operation until the control unit 201 establishes a call when the IP telephone terminal 20-2 receives an incoming call in the IP telephone system of the present embodiment.
At the start of the operation (process 701), the control unit 201 first receives "INVITE" from the CA 10-1 or the caller telephone terminal 20-1 (process 702), and receives the destination telephone number described in "INVITE" and in the memory. Are compared (step 703). If the comparison results are not the same (No at Step 704), the telephone number mismatch message 1205 is transmitted to the CA 10-1 or the originating IP telephone terminal 20-1 (Step 708), and the operation ends (Step 709). ).

For example, the IP address may have been changed due to the IP telephone terminal 20-2 being restarted after a previous call connection. When there is a change in the IP address, the IP telephone terminal 20-2 notifies the CA 10-1 of the telephone number and the changed IP address, and the CA 10-1 manages the latest IP address. Do not notify. Therefore, even if the IP telephone terminal 20-1 transmits a connection request based on the information stored in the memory, it may not reach the desired terminal and may be received by a different terminal. In the present embodiment, as described above, by confirming the coincidence / non-coincidence of the IP address, it is possible to prevent an incoming call from being made at the wrong terminal.
On the other hand, when the comparison results are the same (step 704, Yes), the control unit 201 transmits “180 Ringing” to the CA 10-1 or the caller telephone terminal 20-1 according to the procedure defined in SIP (step 705). The control unit 201 rings an incoming call bell from the speaker unit 208 (process 706), and when “off hook” is detected (process 707), transmits “200 OK” to the CA 10-1 or the caller telephone terminal 20-1 (process 710). The control unit 201 receives “ACK” from the CA 10-1 or the caller telephone terminal 20-1, thereby completing the establishment of the call and starting voice packet communication with the caller telephone terminal 20-1. (Process 712).
When the hooking detection unit 204 detects on-hook (Yes in process 713), IP phone terminal 20-2 transmits “BYE” to CA 10-1 or caller telephone terminal 20-1 (process 719). -1 or “ACK” is received from the originating telephone terminal 20-1 (process 720). By receiving “ACK” (process 720), the control unit 201 ends the communication of the voice packet with the caller telephone terminal 20-1 (process 721), and ends the operation of the control unit 201 (process 722). ).
When “BYE” is received from the caller telephone terminal 20-1 (Yes in process 714), the control unit 201 transmits “ACK” to the CA 10-1 or the caller telephone terminal 20-1 (process 715). ) When the CA 10-1 or the caller telephone terminal 20-1 receives “ACK”, the voice packet communication with the caller telephone terminal 20-1 ends (process 716). When the hooking detection unit 204 detects on-hook (step 717), the operation of the control unit ends (step 718).

(Example of database update)
FIG. 8 shows an internal configuration before and after updating as an example of updating the IP address of the database 301.
When updating the IP address, first, it is checked which item number has the telephone number corresponding to the IP address to be updated. Then, the telephone number and IP address of the item number immediately before the item number having the telephone number corresponding to the IP address to be updated are respectively stored in the storage area of the item number having the telephone number corresponding to the IP address to be updated. And copy. Next, the telephone number and IP address of the item number two immediately before the item number having the telephone number corresponding to the IP address to be updated are each one of the item numbers having the telephone number corresponding to the IP address to be updated. Copy to the storage area of the previous item number. This is repeated sequentially until the telephone number and IP address of item number 1 302 are copied to the storage area of item number 2 303. Finally, the updated IP address is input to the IP address storage area 305 of item number 1302, and the telephone number corresponding to the IP address to be updated is input to the telephone number storage area 306.
8, as a specific example, the IP address of the telephone number “01-2222-3333” (802) registered in item number 2 (303) is changed from “XX.XX.X.X” (805) to “BB”. .BB.BB ”(807) shows the case of updating. First, the updated IP address “BB.BB.BB” (807) and the corresponding telephone number “01-2222-3333” (802) are stored in the control unit 201. Next, the telephone number “06-5555-4444” (801) of item number 1 (302) is input to the telephone number storage area 306 of item number 2 (303), and the item number 1 (302) is stored in the IP address storage area 309. ) IP address “CC.CC.C.C” (804). The telephone number “01-2222-3333” (802) corresponding to the IP address to be updated is input to the telephone number storage area 305 of item number 1 (302), and the updated IP address is input to the IP address storage area 308. Enter "BB.BB.BB" (807). In this case, the contents of the telephone number storage area 307 of item number 3 (304) and the contents of the IP address storage area 310 do not change. By these operations, the updated IP address and the corresponding telephone number are input to the storage area of item number 1 (302) as the latest information.

FIG. 9 shows an internal configuration before registration and after registration as an example of newly adding a telephone number and IP address to the database 301.
When adding a telephone number and an IP address, the telephone number and IP address of item number r-1 immediately preceding item number r (304) are copied to the storage area of item number r. Next, the telephone number and IP address of item number r-2 immediately preceding item number r (304) are copied to the storage area of item number r-1 immediately preceding item number r (304). . This is repeated sequentially until the telephone number and IP address of item number 1 (302) are copied to the storage area of item number 2 (303). Finally, the IP address to be registered is input to the IP address storage area 305 of item number 1 (302), and the telephone number to be registered is input to the telephone number storage area 306.
As a specific example of FIG. 9, a case where a telephone number “01-2222-3333” (907) and an IP address “BB.BB.BB” (908) are newly registered in the database 301 is shown. First, the telephone number “01-2222-3333” (907) and “BB.BB.BB” (908) registered in the control unit 201 are stored. Next, the telephone number “09-9999-9999” (902) of the item number 2 (303) is input to the telephone number storage area 307 of the item number 3 (304), and the item number 2 (303 is stored in the IP address storage area 310. ) IP address “DD.DD.DD” (804). Next, the telephone number “06-5555-4444” (901) of the item number 1 (302) is input to the telephone number storage region 306 of the item number 2 (303), and the item number 1 (302) is stored in the IP address storage region 309. ) IP address “CC.CC.C.C” (904). Further, the telephone number “01-2222-3333” (907) corresponding to the IP address to be updated is input to the telephone number storage area 305 of item number 1 (302), and the updated IP address is input to the IP address storage area 308. Enter "BB.BB.BB" (908). By these operations, the newly added IP address and telephone number are input to the storage area of item number 1 (302) as the latest information.

FIG. 10 is a sequence diagram (1) showing an example of the operation up to establishment of a call of the IP telephone terminal in the IP telephone system of the present embodiment.
This example shows a case where an IP address corresponding to a destination telephone number is searched from a database, and as a result of connecting to the IP address, connection is made to an IP telephone terminal that desires a call.
First, the control unit 201 of the IP telephone terminal 20-1 transmits the first INVITE message to the CA 10-1 (process 1001). When connection to the CA 10-1 is not possible, the control unit 201 of the IP telephone terminal 20-1 does not receive “180 Ringing”. Therefore, after b seconds have passed since the first message transmission, the second INVITE The message is transmitted to the CA 10-1 (process 1002). After elapse of b seconds from the second message transmission, the third INVITE message is output to the CA 10-1 (process 1003). Thereafter, similarly, the INVITE message is repeatedly transmitted to the CA 10-1 until the number of transmissions becomes “a” in a cycle of b seconds. When the a-th INVITE message is transmitted (process 1004) and b seconds elapse, the IP address of the IP telephone terminal 20-2 is searched in the database 301 (process 1006). When the search is successful (process 1005) and the IP address of IP telephone terminal 20-2 is obtained from the database (process 1007), an INVITE message is directly transmitted to IP telephone terminal 20-2 (process 1008).
The IP telephone terminal 20-2 compares the telephone number described in the INVITE message with the own telephone number 1301 in the memory 202. If the numbers match (process 1009), 180 Ringing is transmitted to IP telephone terminal 20-1 (process 1010). The subsequent processing establishes a call according to the existing SIP procedure (processing 1011).

FIG. 11 is a sequence diagram (2) showing an example of the operation up to establishment of a call of the IP telephone terminal in the IP telephone system of the present embodiment.
This example shows a case where an IP address corresponding to a destination telephone number is searched from the database, and as a result of connecting to the IP address, a connection is made to an IP telephone terminal different from the IP telephone terminal that wishes to make a call.
First, the control unit 201 of the IP telephone terminal 20-1 transmits the first INVITE message to the CA 10-1 (process 1101). When the connection to the CA 10-1 is impossible, the IP telephone terminal 1 control unit 201 does not receive “180 Ringing”. Therefore, after b seconds have passed since the first message transmission, the second INVITE message is sent to the CA 10 -1 (process 1102). After elapse of b seconds from the second message transmission, the third INVITE message is output to the CA 10-1 (processing 1103). Thereafter, similarly, the INVITE message is repeatedly transmitted to the CA 10-1 until the number of transmissions becomes “a” in a cycle of b seconds. The a-th INVITE message is transmitted (process 1104), and when b seconds elapse, the IP address of the IP telephone terminal 20-2 is searched in the database (process 1106). When the search is successful (process 1105) and the IP address of the IP telephone terminal 20-2 is acquired from the database (process 1107), an INVITE message is directly transmitted to the IP telephone terminal 20-2 (process 1108).

The IP telephone terminal 20-2 compares the telephone number described in the INVITE message with the own telephone number 1301 in the memory 202. If the numbers do not match (process 1109), a telephone number mismatch message 1205 is transmitted to the IP telephone terminal 20-1 (process 1110). When the IP telephone terminal 20-1 receives the telephone number mismatch message 1205, the IP telephone terminal 20-1 outputs a message indicating that the telephone call is impossible from the speaker 208 (process 1111).
FIG. 12 is a diagram describing the position of the IP packet 1201 of the telephone number mismatch message 1205. The telephone number mismatch message 1205 can be located in the data 1204 inside the UDP header (TCP header) 1203 inside the IP header 1202.
FIG. 15 is an internal block diagram of data 1501 describing a call control protocol.
Data 1501 describing the call control protocol includes route information (route information) 1502, 1503, message name 1504, source IP address 1505, source telephone number 1506, destination telephone number 1507, and internal information. Data 1508 is included.
In the via locations (1502, 1503), every time a message transmitted from the originator passes through each terminal or CA, the IP address of the via location is added. This is used to return a message sent from the incoming side to the outgoing side. In addition, each time the route originator is returned, it is deleted one by one.
FIG. 16 is a sequence diagram showing an example of a message transmission / reception operation in the IP telephone system via the call agent 10-1.
First, the IP telephone terminal 20-1 creates an INVITE message, for example (process 1601). The IP telephone terminal 20-1 writes, for example, a message name 1504, a transmission source IP address 1505, a transmission source telephone number 1506, a transmission destination telephone number 1507, and the like in the INVITE message. Then, the INVITE message is transmitted to the CA 10-1 (process 1605).
The CA 10-1 first fills in the IP address of the IP telephone terminal 20-1 as the transit location 1 1502. The transit location may be entered by an appropriate device (the same applies to the following processing). The CA 10-1 searches the own database for the destination IP address from the destination telephone number (1507) of the INVITE message (process 1602). Then, the INVITE message is transmitted to the IP telephone terminal 20-2 obtained by the search (process 1606).
The IP telephone terminal 20-2 first enters the IP address of the CA 10-1 in the route location 2 1503 of the INVITE message. Next, a 180 Ringing message is created. At this time, the transit location 1 1502 and transit location 2 1503 of the INVITE message are copied (process 1603). Then, a 180 Ringing message is transmitted to the route location 2 1503 which is the latest route location, here, the IP address of the CA 10-1 (process 1607).

The CA 10-1 deletes the via location 2 1503 of the received 180 Ringing message (processing 1604). Then, a 180 Ringing message is transmitted to the via-route 1 1502, which is the latest via-route, here, the IP address of the IP telephone terminal 20-1 (process 1608).
Thereafter, messages are similarly transmitted and received via the CA.
FIG. 17 is a sequence diagram showing an example of a message transmission / reception operation when IP phone terminals communicate directly with each other in the IP phone system. In this case, as described above, it is assumed that IP telephone terminal 20-1 knows the IP address of IP telephone terminal 20-2.
First, IP telephone terminal 20-1 creates an INVITE message (process 1701). For example, the IP telephone terminal 20-1 enters a message name 1504, a transmission source IP address 1505, a transmission source telephone number 1506, a transmission destination telephone number 1507, and the like. Then, the INVITE message is transmitted to the IP telephone terminal 20-2 (process 1703).
The IP telephone terminal 3 first enters the IP address of the IP telephone terminal 20-1 as the transit location 1 1502. Next, a 180 Ringing message is created. At this time, the transit location 1 1502 of the INVITE message is copied (process 1603). Then, a 180 Ringing message is transmitted to the route location 1 1502, which is the latest route location, here, the IP address of the IP telephone terminal 20-1 (process 1704).
In this way, direct communication can be performed without going through the CA 10.
Thereafter, similarly, messages are transmitted and received between the IP telephone terminals 20.

  The present invention can be used, for example, in industries related to IP telephone systems and IP telephone services.

1 is an overall configuration diagram of an IP telephone network according to an embodiment. It is an internal block diagram of an IP telephone terminal. It is an internal block diagram of the database in an IP telephone terminal. It is an example (1) of the flowchart which shows operation | movement of the control part of the transmission side IP telephone terminal in the IP telephone system of this Embodiment. It is an example (2) of the flowchart which shows operation | movement of the control part of the transmission side IP telephone terminal in the IP telephone system of this Embodiment. It is an example (3) of the flowchart which shows operation | movement of the control part of the transmission side IP telephone terminal in the IP telephone system of this Embodiment. It is an example of the flowchart which shows operation | movement of the control part of the receiving side IP telephone terminal in the IP telephone system of this Embodiment. It is an example of an internal block diagram before and after the update of the database at the time of IP address update in the IP telephone terminal. It is an example of an internal block diagram before and after registration of a database when a telephone number and IP address are newly registered in an IP telephone terminal. In the IP telephone system of the present embodiment, it is a sequence diagram showing an example of an operation until establishment of a call of an IP telephone terminal. In the IP telephone system of the present embodiment, it is a sequence diagram showing an example of the operation until the establishment of the call of the IP telephone terminal ends unsuccessfully. It is an internal block diagram of an IP packet including a telephone number mismatch message in the IP telephone system. It is a block diagram of the memory inside an IP telephone terminal. It is an internal block diagram of an IP telephone terminal when using an IP telephone modem and a telephone terminal. It is an internal block diagram of the data describing the call control protocol. It is the sequence diagram which showed an example of the operation | movement in the case of via a call agent in a general IP telephone system. It is the sequence figure which showed an example of the operation | movement in the case of direct communication between IP telephone terminals in a general IP telephone system.

Explanation of symbols

101 IP network 10-1, 2... M Call agent 20-1, 2, 3... N IP telephone terminal 109 DNS server 201 Control unit 202 Memory 203 Telephone number detection unit 204 Hooking detection unit 205 Line connection unit 206 Analog / digital data conversion unit 207 Microphone unit 208 Speaker unit 301 Destination telephone terminal database 302, 303, 304 Item number 305, 306, 307 Telephone number storage area 308, 309, 310 IP address storage area 1201 IP packet 1202 IP header 1203 UDP header or TCP header 1204 Data 1205 Telephone number mismatch message 1301 Own telephone number storage area 1302 Own IP address storage area 1303 Call agent IP address storage area 1401 Telephone terminal 14 02 Telephone line 1403 Telephone line connection unit 1404 IP telephone modem

Claims (6)

The IP for calling between the IP telephone terminals in an IP network having a plurality of IP telephone terminals and a call agent in which a telephone number of the IP telephone terminal and an IP address of the IP telephone terminal are stored correspondingly A phone terminal,
A memory in which a telephone number of another IP telephone terminal and the IP address of the IP telephone terminal are stored correspondingly;
A control unit that performs call connection processing;
With
The control unit inputs a telephone number of a desired destination IP telephone terminal in the first call connection, and transmits a first connection request including the telephone number to the call agent according to a predetermined IP address. And
When the destination IP telephone terminal is called by the call agent according to the first connection request and receives a call signal notification including an IP address corresponding to the telephone number included in the first connection request, the call agent receives Storing the received IP address in the memory corresponding to the telephone number, and establishing a first call connection with the destination IP telephone terminal via the call agent;
In the second call connection after the first call connection, the telephone number of the destination IP telephone terminal is input, and a second connection request including the telephone number is sent to the call agent according to a predetermined IP address. Send
When there is no response from the call agent within a predetermined time due to a failure or congestion of the call agent or a system failure, the memory is searched based on the input telephone number of the destination IP telephone terminal and the corresponding IP address Get
The IP telephone which transmits a third connection request to the destination IP telephone terminal according to the acquired IP address and establishes a second call connection with the destination IP telephone terminal without going through the call agent Terminal. The control unit receives an incoming call,
When the third connection request including the IP address is received from the source IP telephone terminal, the IP address included in the connection request is compared with the IP address of the own device,
The IP telephone terminal according to claim 1, wherein when the IP addresses match, a call signal notification is transmitted to the caller IP telephone terminal, and when the IP addresses do not match, the incoming call is rejected. The controller is
3. The IP telephone terminal according to claim 2, wherein when the IP addresses do not match, a packet including a telephone number mismatch message is transmitted to the source IP telephone terminal. The first connection request stores first route information including an IP address of the source IP telephone terminal and an IP address of the call agent,
In the third connection request, second route information including the IP address of the source IP telephone terminal is stored,
The control unit receives an incoming call,
If the first connection request storing the first route information including the IP address of the source IP telephone terminal and the IP address of the call agent is received from the call agent, the first route information is included. Creating the call signal notification and transmitting the created call signal notification to the caller IP telephone terminal via the call agent according to the first route information; and
When the third connection request storing the second route information including the IP address of the source IP phone terminal is received from the source IP phone terminal, a call signal notification including the second route information is received. By creating and sending the created call signal notification to the destination IP telephone terminal according to the second route information,
The read signal notification is received by the source IP telephone terminal after returning through the route through which the first and third connection requests have passed according to the first and second route information, and the first signal via the call agent. The IP telephone terminal according to claim 2, wherein a call connection is established or a second call connection is established between the IP telephone terminals without going through the call agent. A first IP telephone terminal;
A second IP telephone terminal;
A call agent in which the telephone numbers of the first and second IP telephone terminals and the addresses of the IP telephone terminals are stored correspondingly;
The first and second IP telephone terminals are respectively
A memory in which a telephone number of another IP telephone terminal and the IP address of the IP telephone terminal are stored correspondingly;
A control unit that performs call connection processing;
With
The control unit of the first IP telephone terminal is
In the first call connection, the telephone number of the second IP telephone terminal is input, and a first connection request including the telephone number is transmitted to the call agent according to a predetermined IP address.
When the second IP telephone terminal is called by the call agent according to the first connection request and receives a call signal notification including an IP address corresponding to the telephone number included in the first connection request from the call agent, Storing the received IP address in the memory corresponding to the telephone number, and establishing a first call connection with the second IP telephone terminal via the call agent;
In the second call connection after the first call connection, the telephone number of the second IP telephone terminal is input, and a second connection request including the telephone number is sent to the call agent according to a predetermined IP address. To
If there is no response from the call agent within a predetermined time due to a failure or congestion of the call agent or a system failure, the memory is searched based on the input telephone number of the second IP telephone terminal and the corresponding IP Get the address,
Sending a third connection request to the second IP telephone terminal according to the acquired IP address;
An IP telephone system in which a second call connection is established between the first IP telephone terminal and the second IP telephone terminal. The control unit of the second IP telephone terminal is
When a third connection request including an IP address is received from the first IP telephone terminal, the IP address included in the connection request is compared with the IP address of the own device,
6. A call signal notification is transmitted to the first IP telephone terminal if the IP addresses match to establish a second call connection, and if the IP addresses do not match, the incoming call is rejected. The IP phone system described in 1.

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