JP4778397B2 - IP network system and SIP server - Google Patents

Description

  The present invention relates to an IP network system and a SIP server, and in particular, an IP realized without using a presence server, and realizing a function equivalent to the presence function without reducing the load on the server and causing an increase in equipment cost. The present invention relates to a network system and a SIP server.

  Conventionally, when using an IP phone using an IP network system, it has been necessary to make unnecessary calls over and over again because the other party is in a meeting or talking. In order to solve such a problem, a presence function has been proposed that can determine the state of the other party to be called without making a call.

  A conventional presence function is generally realized by installing a presence server between an IP network and a SIP (Session Initiation Protocol) terminal. By installing a presence server, it becomes possible to unify management of caller-side SIP terminal information and receiver-side SIP terminal information, and the caller-side terminal uses the SIP subscription function for presence information. Obtained from the presence server (see, for example, Patent Document 1).

  In order to acquire presence information, as shown in FIG. 10, the caller-side SIP terminal 11 (hereinafter referred to as “caller-side terminal 11, terminal 11” as an endpoint) that acquires the presence information is called SUBSCRIBE 101. Is transmitted to the presence server 20, and the presence information is acquired by the NOTIFYs 103 and 107.

  Since the SUBSCRIBE 101 also designates the presence information acquisition period, when the presence information is acquired for a certain period or longer, the caller-side terminal 11 transmits the SUBSCRIBE 101 at a certain period.

  The recipient-side SIP terminal 12 (hereinafter referred to as “recipient-side terminal 12, terminal 12” as appropriate), which is the endpoint on the side providing the presence information, updates the presence server 20 each time it updates its presence information. Then, PUBLISH 105 is transmitted. The presence server 20 that has received the PUBLISH 105 transmits NOTIFY 107 to notify the caller side terminal 11 corresponding to the receiver side terminal 12 of the presence information.

  In addition to the terminal 11, when there is an endpoint on the caller side with respect to the terminal 12, NOTIFY is also transmitted to the endpoint to notify the presence information. The SIP terminal 13 is also a caller side terminal corresponding to the SIP terminal 12 and receives notification of presence information by NOTIFY 109.

  However, the conventional IP network system has a problem that the number of transmissions of NOTIFY and SUBSCRIBE increases due to the expansion of the scale of the IP network system due to the increase in the number of callers, and the load on the system increases.

  Therefore, in order to solve the above problem, for example, in Patent Document 2, redialing is performed using redial information returned from the partner terminal by the SIP call control procedure, and the communication success probability is reduced by reducing unnecessary redialing. In order to increase, in the caller side terminal, the SIP call control unit makes a call to the receiver side terminal by a call control procedure using SIP, and transmits an INVITE command which is a SIP call control procedure signal. If it is busy when the INVITE command is received, a status code (Busy Here) is returned as a response indicating that the INVITE command is busy, and the redial control unit of the caller side terminal returns a Retry-- included in the status code. In accordance with the redial information “After”, the receiver terminal is redialed after 120 seconds. Communication terminal device or the like have been proposed to dial.

JP 2005-39507 A JP 2004-112182 A

  However, in the conventional communication terminal device and the like, in order to realize an auto redial function equivalent to the conventional presence function, since signals are frequently exchanged, the load on the SIP server increases and the terminal has its own In order to adapt to the existing IP network system, the function of all terminals that use the auto redial function needs to be improved, and there is a problem that the equipment cost increases.

  Therefore, the present invention has been made in view of the problems in the conventional communication terminal device and the like, and reduces the load on the SIP server when realizing an auto redial function equivalent to the conventional presence function. An object of the present invention is to provide an IP network system and a SIP server that can be applied to an existing IP network system including a SIP terminal as it is and that do not cause an increase in equipment cost.

  In order to achieve the above object, the present invention provides an IP network system including a SIP server that communicates with a caller side terminal and a receiver side terminal, wherein the caller side terminal is connected to the SIP server with respect to the SIP server. The SIP server transmits a call control signal, the SIP server stores the caller side terminal in association with the receiver side terminal set in the SIP call control signal, monitors the receiver side terminal for a predetermined period, and If a registration request signal is received from the receiver side terminal within a predetermined period, a transfer request signal is transmitted to the caller side terminal, and the caller side terminal sends a SIP call control signal to the SIP server. The SIP server transmits the SIP call control signal to the receiver side terminal, and the sender side and the receiver side terminal start communication between both terminals.

  And according to this invention, since the number of signals used in order to implement | achieve the auto redial function equivalent to the conventional presence function can be reduced, the load concerning a server can be reduced. Further, since the SIP terminal is not specially modified and the SIP server according to the present invention can be introduced into the existing IP network system, the equipment cost is not increased.

  In the IP network system, when the SIP server transmits a transfer request signal to the caller side terminal, or when the caller side and the receiver side terminal start communication between both terminals, The monitoring can be terminated. This eliminates the need for monitoring from after successful communication between the caller-side terminal and the receiver-side terminal until the monitoring period expires, thereby reducing the load on the SIP server.

  The present invention is also a SIP server that communicates with a caller side terminal and a receiver side terminal, and when the SIP call control signal is received from the caller side terminal, the caller side terminal is connected to the SIP call control signal. And storing means associated with the receiver side terminal set to the receiver, and when receiving a registration request signal from the receiver side terminal, searches the sender side terminal corresponding to the receiver side terminal from the storage means. An automatic redial means for transmitting a transfer request signal to the caller-side terminal, and a time measuring means for measuring a monitoring period set in the SIP call control signal.

  And according to this invention, since the number of signals used in order to implement | achieve the said auto redial function can be reduced as mentioned above, the load concerning a server can be reduced. Further, since the SIP terminal is not specially modified and the SIP server according to the present invention can be introduced into the existing IP network system, the equipment cost is not increased.

  As described above, since the IP network system equipped with the SIP server according to the present invention can reduce the number of signals used to realize the autodial function equivalent to the conventional presence function, the load on the server Can be reduced. Further, since the SIP terminal is not specially modified and the SIP server according to the present invention can be introduced into the existing IP network system, the equipment cost is not increased.

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

  FIG. 1 shows an embodiment of an IP network system including a SIP server according to the present invention. This IP network system includes a first SIP server 1 (hereinafter referred to as “server 1” as appropriate), a second It comprises a SIP server 2 (hereinafter referred to as “server 2” as appropriate) and SIP terminals 11, 12, 13 (hereinafter referred to as “terminals 11, 12, 13” as appropriate). , 13 is a sender side terminal, and the SIP terminal 12 is a receiver side terminal.

  The server 1 according to the present invention includes a SIP terminal list 21, a redial function 22, and a timer control function 23, as shown in FIG. 3, and is installed at a position through which call connection signaling is routed. . Further, as shown in FIG. 4, the SIP terminal list 21 is managed by replacing the sender-side terminal information and the receiver-side terminal information with an identifier representing the sender-side terminal and an identifier representing the receiver-side terminal, respectively. To do.

  The server 2 is a SIP server having a conventional function, and has functions such as a proxy server, a registration server, and a location server.

  The terminals 11 to 13 are endpoints having a function as a SIP UA (SIP user agent).

  Each of the server 1 and the server 2 may be provided, or one server 1 and one server 2 may be provided. Conversely, the server 1 and the server 2 may be provided. You may comprise as follows.

  Next, the operation of the IP network system according to the present invention will be described with reference to the drawings. The server 1 also serves as a terminal registration server.

  As illustrated in FIG. 2, the terminal 11 transmits an INVITE (SIP call control signal) 111 to the terminal 12. However, the terminal 12 has not yet transmitted REGISTER (registration request signal) to the IP network system (hereinafter referred to as “system” as appropriate), and receives the INVITE 111 because the state of the endpoint is not REGISTER. I can't.

  Therefore, as shown in FIG. 5, the terminal 11 sets the monitoring period (3600 seconds) of the terminal 12 and information of the receiver-side terminal 12 in the INVITE 111 and transmits the information to the server 1. The monitoring period set to 3600 seconds is an example, and may be less than 3600 seconds or more.

  As shown in FIG. 2, when the server 1 that has received the INVITE 111 has already received the REGISTER from the terminal 12 at the time of receiving the INVITE 111, the server 1 sends the INVITE 111 to the terminal 12 under the same control as the conventional SIP server. To make a communication connection to be described later.

  Conversely, if REGISTER is not received from the terminal 12, auto redial is registered in the redial function 22, as shown in FIG. Specifically, the SIP server function 24 transmits a registration notification 153 to the redial function 22, and the redial function 22 corresponds to the information of the terminal 11 and the information of the terminal 12 set in the registration notification, respectively. Register in the SIP terminal list 21.

  Then, the redial function 22 registers 155 the monitoring period set in the INVITE 111 with respect to the timer control function 23. The SIP server function 24 starts monitoring the terminal 12 based on the monitoring period registered in the timer control function 23. For monitoring, for example, a keep alive method in which messages in a dialog are periodically transmitted to the terminal 12 can be used.

  As shown in FIG. 2, when the server 1 receives REGISTER 117 from the terminal 12 before the monitoring period expires, the server 1 returns a 200 response 120 to the terminal 12, and the SIP server function 24 7, the registration success notification 140 of the terminal 12 is transmitted to the redial function 22.

  After receiving the registration success notification 140, the redial function 22 searches the SIP terminal list 21 for the caller-side terminal 11 corresponding to the terminal 12 that has transmitted REGISTER, and transmits the calling instruction 141 to the SIP server function 24. Then, the SIP server function 24 transmits REFER 121 for instructing reconnection to the terminal 11. After that, as shown in FIG. 2, using the conventional SIP control, the terminal 11 that has received the REFER 122 transmits an INVITE 125 based on the identification of the terminal 12 specified by the REFER 122 to start communication. At the same time, the timer control function 23 in the server 1 cancels the monitoring period set in the INVITE 111, and the server 1 ends the monitoring.

  In the present embodiment, the monitoring is terminated when the terminal 11 succeeds in auto redial. However, this is an example, and monitoring is performed when the server 1 transmits REFER 121 to the terminal 11. May be released.

  The terminal 13 can also realize an auto redial function for the terminal 12 by the same operation as the terminal 11.

  Next, another embodiment of the IP network system according to the present invention will be described with reference to the drawings.

  As shown in FIG. 8, the IP network system according to the present invention has a configuration in which the server 2 is removed from the embodiment shown in FIG. 1, and an SIP server 31 (hereinafter referred to as “server 31” as appropriate) It is comprised with the terminals 11-13. Since the terminals 11, 12, and 13 have the same configuration as the terminals 11 to 13 in the above embodiment, detailed description thereof is omitted.

  The server 31 has both the functions of the server 1 and the server 2 in the above-described embodiment, and has a configuration in which the function of the server 2 is newly added to the SIP server function 24 of the server 1. With this configuration, a function equivalent to the conventional presence function can be realized only by providing one SIP server according to the present invention instead of the presence server in the conventional IP system.

  Although detailed description is omitted, the terminal 13 can also realize an auto redial function for the terminal 12 by the same operation as the terminal 11. In the present embodiment, the sender terminal (terminal 11) and the receiver terminal (terminal 12) are each one, but this is only an example, and of course, two or more each are provided. May be.

It is a block diagram which shows one Embodiment of the IP network which installed the SIP server (1st SIP server) concerning this invention. It is a sequence diagram which shows an example at the time of implement | achieving an auto redial function with the SIP server concerning this invention. It is a block diagram which shows an example of a structure of the SIP server concerning this invention. It is a figure which shows the SIP terminal list used with the SIP server concerning this invention. It is a figure which shows an example of the call control signal (INVITE) transmitted from the caller side by the SIP server concerning this invention. It is a sequence diagram which shows an example at the time of registering the monitoring from the caller side by the SIP server concerning this invention. It is a sequence diagram which shows the case where the call origination is instruct | indicated with respect to the caller side by the SIP server concerning this invention. It is a block diagram which shows one Embodiment of the IP network structure which installed the SIP server concerning this invention. It is a sequence diagram which shows an example at the time of implement | achieving an auto redial function by the SIP server concerning this invention. It is a sequence diagram for implement | achieving the conventional presence function.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st SIP server 2 2nd SIP server 11 SIP terminal 12 SIP terminal 13 SIP terminal 20 Presence server 21 SIP terminal list 22 Redial function 23 Timer control function 24 SIP server function 31 SIP server

Claims (3)

An IP network system including a SIP (Session Initiation Protocol) server that communicates with a sender-side terminal and a receiver-side terminal,
The caller side terminal transmits a SIP call control signal to the SIP server,
The SIP server stores the caller terminal in association with the receiver terminal set in the SIP call control signal, monitors the receiver terminal for a predetermined period, and receives the reception terminal within the predetermined period. When a registration request signal is received from the caller side terminal, a transfer request signal is transmitted to the caller side terminal,
The caller side terminal sends a SIP call control signal to the SIP server,
The SIP server forwards the SIP call control signal to the receiver-side terminal;
The IP network system, wherein the sender side and receiver side terminals start communication between both terminals.   The monitoring ends when the SIP server transmits a transfer request signal to the caller side terminal, or when the caller side and the receiver side terminal start communication between both terminals. The IP network system according to claim 1. A SIP (Session Initiation Protocol) server that communicates with a sender-side terminal and a receiver-side terminal,
Storage means for storing the caller-side terminal in association with the caller-side terminal set in the SIP call control signal when receiving the SIP call control signal from the caller-side terminal;
Auto redial for retrieving a caller-side terminal corresponding to the receiver-side terminal from the storage means and transmitting a transfer request signal to the caller-side terminal when a registration request signal is received from the receiver-side terminal Means,
A SIP server comprising: time measuring means for measuring a monitoring period set in the SIP call control signal.

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