JP2011029703A - Sip server device, and call connection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an SIP server device changing the setting of the relay communication speed of a gateway device for relaying call data to prevent communication voice from breaking up. <P>SOLUTION: In this SIP server device, voice data total transmission capacity is calculated based on session information from a gateway device; an optimum communication speed when the gateway device transmits call data is determined based on the voice data total transmission capacity; and, when all the sessions for the gateway device are determined to be completed, a speed change setting request to use the optimum communication speed as the present set communication speed is issued to the gateway device. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a SIP server device and a call connection system that establish a session according to a SIP (Session Initiation Protocol) protocol.

  2. Description of the Related Art A SIP server device (hereinafter simply referred to as a SIP server) that connects calls between VoIP (Voice over Internet Protocol) communication terminals according to the SIP protocol is known. After the call connection, the call data between the VoIP communication terminals is relayed by the gateway device. In response to a call connection request from the VoIP communication terminal, the SIP server makes a call connection with the VoIP communication terminal on the called side, and selects a gateway device that should relay call data related to the call connection from among the plurality of gateway devices. One process is selected for each call connection request. On the other hand, the gateway device relays call data for a plurality of sessions, but it is desired to reduce its power consumption. For example, Patent Document 1 discloses an information processing apparatus that suppresses the communication speed of data transmitted to and received from an external communication apparatus in order to reduce power consumption.

International Publication WO2003 / 096651 Pamphlet

  However, when the information processing apparatus disclosed in Patent Document 1 is applied to communication that requires real-time performance such as voice communication, when the throughput of call data transmission fluctuates during a call, the voice is transmitted by a communication speed switching process. There was a problem of interruption.

  The present invention has been made in view of the above-described problems, and provides a SIP server and a call connection system capable of setting and changing the relay communication speed of a gateway device that relays call data so that call voice is not interrupted. For the purpose.

  The SIP server device according to the present invention selects one of at least two gateway devices as a relay gateway device in response to a call connection request from a VoIP communication terminal, and the VoIP communication terminal and the relay gateway device according to a SIP protocol. A total capacity calculation unit for calculating a total transmission capacity of voice data for the relay gateway apparatus based on session information from the relay gateway apparatus, and a total voice data total An optimal communication speed determining unit that determines an optimal communication speed when the relay gateway device transmits call data based on a transmission capacity; and the optimal communication when it is determined that all sessions for the relay gateway device are completed. Speed is currently set Communication speed A speed change setting request unit that emits the speed change setting request should do effect to the relay gateway device, characterized in that it comprises a.

  Also, the call connection system according to the present invention selects at least two gateway devices and one of the gateway devices as a relay gateway device in response to a call connection request from a VoIP communication terminal, and performs the call according to the SIP protocol. A call connection system including a SIP server device that establishes a session between a VoIP communication terminal that has issued a connection request and the relay gateway device, wherein the SIP server device includes session information from the relay gateway device. A total capacity calculation unit that calculates a total transmission capacity of voice data for the relay gateway apparatus based on the optimum capacity for determining an optimum communication speed when the relay gateway apparatus transmits call data based on the total transmission capacity of voice data A communication speed determination unit and the relay gateway; A speed change setting request unit that issues a speed change setting request to the relay gateway device to determine that the optimum communication speed should be the current set communication speed when it is determined that all sessions for the device have been completed, The gateway device includes a communication speed control unit that sets the optimum communication speed as the currently set communication speed in response to the speed change setting request, and a relay unit that relays the call data at the current set communication speed. It is characterized by that.

  According to the SIP server or the call connection system of the present invention, it is possible to change the setting of the relay communication speed of the gateway device that relays the call data so that the call voice is not interrupted.

It is a block diagram showing a SIP server with a VoIP terminal, a gateway apparatus, and a communication network. It is a sequence diagram showing transmission / reception of the signal in the call connection and call disconnection by a SIP protocol. It is a figure showing a session management table. It is a figure showing a candidate communication speed table. It is a figure showing a setting communication speed table. It is a figure showing a switching restriction table. It is a flowchart showing a communication speed change setting process routine. It is a figure showing the information of the part newly added to the session management table. It is a flowchart showing the optimal communication speed selection processing routine.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a SIP server 100 according to the present embodiment in which VoIP terminals 200-1 to 200-n (n is an integer of 2 or more), gateway devices 300-1 to 300-m (m is an integer of 2 or more), and a communication network 400. It is a block diagram represented with. Hereinafter, a communication system constituted by these is referred to as a SIP call connection system 1.

  The SIP server 100 establishes a session between the calling VoIP terminal (any one of 200-1 to 200-n) that issued the call connection request and the gateway device (any one of 300-1 to 300-m). This is a so-called SIP server that establishes and establishes a call connection with the called VoIP terminal. FIG. 2 is a sequence diagram showing signal transmission / reception in call connection and call disconnection by the SIP protocol. A procedure for establishing a call connection using the SIP protocol will be described below. First, the calling terminal transmits an “INVITE” message, which is a call connection request, to the called terminal. When the handset is lifted at the called terminal, the called terminal transmits a “200 OK” message to the calling terminal. The “200 OK” message includes session information such as an encoding method and a packet transmission cycle commonly used by the volume terminals in voice communication. The calling terminal transmits an “ACK” message to the called terminal in order to notify the called terminal that the “200 OK” message has been received. The call is started when the called terminal receives the “ACK” message. When the call is terminated, a “BYE” message is issued from the calling or called terminal to the other terminal. The terminal that has received the “BYE” message issues a “200 OK” message to the terminal that has issued the “BYE” message, and the terminal receives this message, and the call is terminated.

  Since the SIP server 100 relays these messages, it can acquire session information included in “200 OK” issued at the time of call connection. In addition, the SIP server 100 can determine that the session has ended by relaying the “BYE” message.

  The VoIP terminal 200-1 issues a call connection request in accordance with the SIP protocol to the SIP server. After the call connection is established, the VoIP terminal 200-1 is a packet including voice data with the other party's VoIP terminal via the communication network 400 such as the Internet. Is a communication terminal having a function of transmitting and receiving. The packet is relayed by any one of the gateway devices 300-1 to 300-m. Each of the VoIP terminals 200-2 to 200-n has the same configuration as that of the VoIP terminal 200-1.

  The gateway device 300-1 is a packet relay device that includes a communication speed control unit 310 and a communication interface (IF) unit 320. The communication speed control unit 310 changes and sets the signal transmission / reception and packet relay speed (throughput) by the communication IF unit 320 in response to a speed change setting request from the SIP server 100. The communication IF unit 320 has a function of transmitting and receiving data and signals via the communication network 400. In addition, the communication interface unit 320 uses the speed (throughput) set by the communication speed control unit 310 to receive packets that have arrived from the VoIP terminals (at least one of 200-1 to 200-n) via the communication network 400. (Hereinafter, the communication IF unit 320 is also referred to as a relay unit 320). The communication IF unit 320 can also mutually convert packet data having different communication protocols when relaying. Each of gateway apparatuses 300-2 to 300-m has the same configuration as gateway apparatus 300-1.

  The SIP server 100 includes an interface unit 110, a call connection processing unit 120, a storage unit 130, and a communication speed switching instruction unit 140.

  The interface unit 110 is connected to a call connection processing unit 120, a set communication speed table 133, which will be described later, and a speed change setting request unit 144, and receives data such as an SIP message and a speed change setting request via the communication network 40. It is a communication interface for transmitting and receiving.

  The call connection processing unit 120 executes call connection processing according to the “INVITE” message that is a call connection request, call disconnection processing according to the “BYE” message that is a call disconnection request, and the like according to the SIP protocol.

  The storage unit 130 is a storage medium such as a hard disk or a RAM including a session management table 131, a candidate communication speed table 132, a set communication speed table 133, and a switching restriction table 134.

  The session management table 131 is a table that stores session information for each session for each gateway device (300-1 to 300-m). That is, the session management table 131 stores the session information included in the “200 OK” message from each of the gateway devices 300-1 to 300-m.

  FIG. 3 shows a session management table. The “gateway device” is a unique identifier for identifying each of the gateway devices 300-1 to 300-m. Here, for convenience, the gateway devices 300-1, 300-2,. The “session number” is a number that is sequentially assigned to the session that the gateway device is subject to packet relay, and is 1, 2,... A session number is assigned to each gateway device. “Call connection state” and “session number” indicate a call connection state such as “busy” for each session. The “encoding method” is, for example, G. 729a and G.G. 711 represents a speech encoding scheme. The “packet transmission interval” represents a packet transmission interval such as 20 milliseconds for each session. The “voice data transmission capacity for each session” represents a voice data transmission capacity such as 24 Kbps for each session. The “total voice data transmission capacity” is a total voice data transmission capacity such as 2950 Kbps for each gateway device, and is obtained as a total value of “voice data transmission capacity for each session”.

  The candidate communication speed table 132 is a table that stores candidate communication speeds corresponding to the total voice data transmission capacity for each gateway device (300-1 to 300-m). FIG. 4 is a diagram illustrating a candidate communication speed table. The “gateway device” is a unique identifier for identifying each of the gateway devices 300-1 to 300-m. The “total voice data transmission capacity” is a range of the total voice data transmission capacity that is a total value of the voice data transmission capacity for each session, and is, for example, less than 3 Mbps or 30 Mbps or more. The “candidate communication speed” is a communication speed setting candidate, and is, for example, 10 Mbps or 100 Mbps. The candidate communication speed is set for each gateway device. For example, for the gateway device 300-1, the candidate communication speed when the total voice data transmission capacity is less than 3 Mbps is 10 Mbps, and the candidate communication speed when the total voice data transmission capacity is 3 Mbps or more and 30 Mbps or less is 100 Mbps. The candidate communication speed is 1 Gbps when the total voice data transmission capacity is 30 Mbps or more.

  The set communication speed table 133 is a current set communication speed for each gateway device (300-1 to 300-m). FIG. 5 shows a set communication speed table. The “gateway device” is a unique identifier for identifying each of the gateway devices 300-1 to 300-m. “Currently set communication speed” is the current set communication speed, and is, for example, 10 Mbps. The set communication speed may be acquired from each of the gateway devices 300-1 to 300-m via the communication network 400, or may be set by the optimum communication speed determination unit 142 as the optimum communication speed.

  The switching restriction table 134 is a table used for temporally restricting the communication speed change setting. FIG. 6 shows a switching restriction table. The “gateway device” is a unique identifier for identifying each of the gateway devices 300-1 to 300-m. The “elapsed time after change setting” is the elapsed time from the time when the communication speed is changed (set) to the current time. “Minimum switching interval” is a time for limiting the change setting (switching) of the communication speed. For example, in the case of the gateway apparatus 300-1, when the communication speed change setting is made at 15:00, the communication speed change setting cannot be made again after 1 hour which is the "shortest switching interval" has passed, that is, until 16:00 has passed. . Note that such a restriction is imposed only when changing from high speed to low speed such as changing from 100 Mbps to 10 Mbps.

  The communication speed switching instruction unit 140 includes an arithmetic processing function such as a CPU including a total capacity calculation unit 141, an optimum communication speed determination unit 142, a relay gateway device change unit 143, and a speed change setting request unit 144. It is a microprocessor.

  The total capacity calculation unit 141 is a gateway device (any one of 300-1 to 300-m, which relays call data of a session newly established by the call connection processing unit 120 (hereinafter referred to as a newly established session). The total voice data transmission capacity for the established gateway device) is calculated based on the session management table 131. For example, when the gateway device 300-1 is a newly established gateway device, the total capacity calculation unit 141 adds up the “voice data transmission capacity for each session” corresponding to the gateway device 300-1 in the session management table 131 (FIG. 3). The value is calculated as the voice data total transmission capacity. In the calculation, the voice data transmission capacity for the newly established session is also included in the total value.

  Further, the total capacity calculating unit 141 exchanges the “BYE” message between the VoIP terminal (any one of 300-1 to 300-n) and the gateway device (any one of 300-1 to 300-m). In this case, information about a session (hereinafter referred to as a call end session) corresponding to the “BYE” message is deleted from the session management table 131, and then the gateway device (hereinafter referred to as a call end gateway device) is deleted. The total voice data transmission capacity for each session is summed to calculate the total voice data transmission capacity. For example, when the gateway device 300-1 is a call termination gateway device, the total capacity calculation unit 141 adds up the “voice data transmission capacity for each session” corresponding to the gateway device 300-1 in the session management table 131 (FIG. 3). The value is calculated as the voice data total transmission capacity. In the calculation, the voice data transmission capacity for the call termination session is not included.

  The optimum communication speed determination unit 142 determines one of the candidate communication speeds stored in advance in the candidate communication speed table 132 based on the total voice data transmission capacity calculated by the total capacity calculation unit 141 for the newly established gateway device. Select the optimum communication speed. For example, when the gateway device 300-1 is a newly established gateway device and the total voice data transmission capacity is 10 Mbps, “3 Mbps or more” of the “total voice data transmission capacity” in the candidate communication speed table 132 (FIG. 4). , "Candidate communication speed" 100 Mbps corresponding to "less than 30 Mbps" is selected as the optimum communication speed.

  The relay gateway device changing unit 143 differs in the optimum communication speed (selected by the optimum communication speed determining unit 142) and the currently set communication speed (set in the set communication speed table 133) for the newly established gateway device. The gateway device (any one of 300-1 to 300-m) other than the newly established gateway device relays the call data for the session established after the newly established session (hereinafter, A request for relay gateway device) is given to the call connection processing unit 120. For example, when the gateway device 300-1 is a newly established gateway device and the currently set communication speed is 10 Mbps, and the optimum communication speed selected by the optimum communication speed determination unit 142 is 100 Mbps, the relay gateway device change unit 143 Gives a request to the call connection processing unit 120 to make any one of the gateway devices 300-2 to 300-m a relay gateway device.

  When the speed change setting request unit 144 determines that all sessions for the newly established gateway device have been completed based on, for example, a “BYE” message exchanged at the end of the call, the speed change setting request unit 144 sets the optimum communication speed as the currently set communication speed. A speed change setting request for requesting a change setting to be issued is issued to the newly established gateway device. For example, it is a speed change setting request for changing the currently set communication speed of 10 Mbps to the optimum communication speed of 100 Mbps. The speed change setting request is transmitted from the interface unit 110 to the newly established gateway device (any one of the gateway devices 300-1 to 300-m) via the communication network 400. In response to the speed change setting request received by the communication IF unit 320, the communication speed control unit 310 of the newly established gateway device performs change setting with the optimum communication speed as the currently set communication speed.

Next, the communication speed change setting process will be described. Here, in the order of a to g, when the currently set communication speed is changed from low speed to high speed (from 10 Mbps to 100 Mbps), when the current set communication speed is maintained at 10 Mbps (10 Mbps), the current set communication speed is changed from high speed to low speed. In the case of changing settings (from 10 Mbps to 100 Mbps), other cases based on processing in these cases will be described.

[A. Communication speed change setting process: Setting change from currently set communication speed of 10 Mbps to 100 Mbps]
FIG. 7 is a flowchart showing a communication speed change setting processing routine. Hereinafter, the communication speed change setting process by the communication speed switching instruction unit 140 will be described with reference to FIG. 7 in addition to FIG. In the explanation, the following assumptions are made. The gateway device 300-1 has a currently set communication speed of 10 Mbps and a total voice data transmission capacity of 2950 Kbps. The gateway apparatus 300-2 has a currently set communication speed of 10 Mbps and a total voice data transmission capacity of 5000 Kbps. The encoding method used in the newly established session between the VoIP terminal 200-1 and the gateway device 300-1 is G.264. 711. The packet transmission cycle of the gateway device 300-1 is 20 milliseconds. Further, the session management table 131 is shown in FIG. 3, the candidate communication speed table 132 is shown in FIG. 4, the set communication speed table 133 is shown in FIG. 5, and the switching restriction table 134 is shown in FIG.

  The communication speed change setting processing routine is started by the communication speed switching instruction unit 130 when adding session information to the session management table 131 (starting a session) or deleting session information (ending a session).

  First, the VoIP terminal 200-1 transmits an “INVITE” message, which is a call connection request, to the gateway apparatus 300-1 via the SIP server 100. The gateway apparatus 300-1 transmits a “200 OK” message to the SIP server 100 as a response.

  The call connection processing unit 120 extracts the session information included in the “200 OK” message received by the interface unit 110, and adds this to the session management table 131 (FIG. 7: Step S101). FIG. 8 is a diagram illustrating information of a part newly added to the session management table 131 by the call connection processing unit 120. The call connection processing unit 120 stores information included in the session information in association with each column of the session management table 131. The “session number” is 3. The “call connection state” is “200 OK” before the call state is established. “Encoding method” 711 and “packet transmission interval” 20 milliseconds are information included in the session information. The total capacity calculation unit 141 calculates “audio data transmission capacity for each session” 80 Kbps from these pieces of information.

  The voice data transmission capacity for each session is calculated as follows, for example. Encoding method The audio data size SS of one packet of audio data is calculated from the transmission band of 641 Kbps 711 and the packet transmission interval of 20 milliseconds. Specifically, the audio data size SS = (64 Kbps / 8 bits) × (20 milliseconds / 1 second) = 160 bytes. When the IP header (20 bytes), UDP header (8 bytes), and RTP header (12 bytes) are added to this, the total capacity CA is 160 + 20 + 8 + 12 = 200 bytes. When converted to bit units, 200 × 8 = 1600 bits. is there. Further, the voice data transmission capacity is calculated by dividing the total capacity CA by the packet transmission interval of 20 milliseconds. Specifically, audio data transmission capacity = 1600 bits / 20 milliseconds = 1600 bits / 0.02 seconds = 80000 bps = 80 Kbps.

  Returning to the description of FIG. 1 and FIG. 7, the total capacity calculation unit 141 adds the voice data transmission capacity 80 Kbps for the newly established session to the current total voice data transmission capacity 2950 Kbps to obtain the voice data for the newly established session. The total audio data transmission capacity 3030 Kbps including the transmission capacity is calculated (FIG. 7: step S102).

  The optimum communication speed determination unit 142 refers to the candidate communication speed table 132 (FIG. 4), and sets the voice data total transmission capacity 3030 Kbps calculated by the total capacity calculation unit 141 to “3 Mbps or more and less than 30 Mbps”. Corresponding “candidate communication speed” 100 Mbps is selected as the optimum communication speed (FIG. 7: step S103).

  More specifically, the optimum communication speed determination unit 142 selects the optimum communication speed according to the optimum communication speed selection processing routine shown in FIG. First, the optimum communication speed determining unit 142 refers to the set communication speed table 133 (FIG. 5) and determines that the currently set communication speed of the gateway device 300-1 is 10 Mbps (FIG. 9: Step S201). Next, the optimum communication speed determination unit 142 determines that the total voice data transmission capacity 3030 Kbps is 3 Mbps or more (FIG. 9: Step S202). Subsequently, the optimum communication speed determining unit 142 refers to the candidate communication speed table 132 and selects 100 Mbps as the optimum communication speed (FIG. 9: Step S203).

  The relay gateway device changing unit 143 determines that the optimum communication rate 100 Mbps selected by the optimum communication rate determining unit 142 is different from the currently set communication rate 10 Mbps, and gateway devices other than the gateway device 300-1 (newly established gateway device). A relay gateway device change request that uses (any one of 300-2 to 300-m) as a gateway device (relay gateway device) that relays call data for a session established after a newly established session is sent to the call connection processing unit 120. (FIG. 7: Step S104). The call connection processing unit 120 in response to the relay gateway device change request, in response to a call connection request issued from any one of the VoIP terminals 200-1 to 200-n thereafter, of the gateway devices 300-2 to 300-m. Either one is a relay gateway device. For example, priorities are assigned in advance to each of the gateway devices 300-1 to 300-m, and gateway devices (other than 300-1) to be used as relay gateway devices are selected in that order. By this processing, the gateway device 300-1 does not become a relay gateway device until at least the communication speed change setting processing routine ends.

  When the “BYE” message is exchanged between the VoIP terminal and the gateway device 300-1, the speed change setting requesting unit 144, for all the sessions that are establishing the call connection, It is determined that the session is completed (FIG. 7: Step S105). In this case, the speed change setting request unit 144 issues a speed change setting request for requesting a change setting in which the optimum communication speed of 100 Mbps is the current setting communication speed to the gateway device 300-1 (FIG. 7: Step S106). In this way, the speed change setting request unit 144 issues a speed change setting request when all the sessions for the gateway device 300-1 are completed.

  The speed change setting request is transmitted from the interface unit 110 to the gateway device 300-1 via the communication network 400. In response to the speed change setting request received by the communication IF unit 320, the communication speed control unit 310 of the gateway device 300-1 performs change setting with the optimum communication speed of 100 Mbps as the currently set communication speed. That is, the currently set communication speed is switched from 10 Mbps to 100 Mbps.

  The relay gateway device changing unit 143 changes the gateway device 300-1 after the speed change setting request is issued by the speed change setting requesting unit 144 or after receiving the communication speed change setting completion notification from the gateway device 300-1. A relay restriction release notification that the relay gateway device may be used is issued to the call connection processing unit 120. After receiving the relay restriction release notification, the call connection processing unit 120 can select the gateway device 300-1 as the relay gateway device.

The above is an example in which the current setting communication speed of the gateway device 300-1 is changed from 10 Mbps to 100 Mbps, that is, the current setting communication speed of the gateway device 300-1 is changed from low to high. When maintaining the currently set communication speed of 1 is as follows.

[B. Communication speed change setting process: When maintaining the currently set communication speed of 10 Mbps]
Hereinafter, the communication speed change setting process by the communication speed switching instruction unit 140 will be described with reference to FIGS. 1, 7, and 9 again. In the explanation, the following assumptions are made. The VoIP terminal 200-1 does not make a call connection request, the currently set communication speed of the gateway device 300-1 is 10 Mbps, and the total voice data transmission capacity is 2950 Kbps.

  First, since the call connection processing unit 120 does not receive a signal related to the “200 OK” message at the interface unit 110, the information in the session management table 131 is as it is (FIG. 7: step S101).

  Since the total capacity calculation unit 141 has not received the information on the newly established session, it calculates 2950 Kbps, which is the current total transmission capacity of voice data (FIG. 7: step S102).

  The optimum communication speed determination unit 142 refers to the candidate communication speed table 132 (FIG. 4), and corresponds to “less than 3 Mbps” that is a range including the voice data total transmission capacity 2950 Kbps calculated by the total capacity calculation unit 141. "Candidate communication speed" 10 Mbps is selected as the optimum communication speed (FIG. 7: step S103).

  More specifically, the optimum communication speed determination unit 142 selects the optimum communication speed according to the optimum communication speed selection processing routine shown in FIG. First, the optimum communication speed determining unit 142 refers to the set communication speed table 133 (FIG. 5) and determines that the currently set communication speed of the gateway device 300-1 is 10 Mbps (FIG. 9: Step S201). Next, the optimum communication speed determining unit 142 determines that the total voice data transmission capacity 2950 Kbps is less than 3 Mbps. Further, the optimum communication speed determining unit 142 refers to the candidate communication speed table 132 and selects 10 Mbps as the optimum communication speed (FIG. 9: Step S202).

  The relay gateway device changing unit 143 determines that the optimum communication speed 10 Mbps selected by the optimum communication speed determination unit 142 is the same as the currently set communication speed 10 Mbps. The relay gateway device changing unit 143 sends a relay gateway device change request to the gateway device 300-1 as a gateway device (relay gateway device) that relays call data for a session established after a newly established session, as currently set. This is given to the call connection processing unit 120 (FIG. 7: Step S104).

  Hereinafter, the processing in the case of maintaining the currently set communication speed is a series of processing without performing the processing of confirming the end of all sessions in FIG. 7 (FIG. 7: Step S105) and the speed change setting unit (FIG. 7: Step S106). Exit.

As described above, when the current setting communication speed of the gateway device 300-1 is maintained at 10 Mbps, that is, when the current setting communication speed of the gateway device 300-1 is maintained, the change is made from high speed to low speed. It becomes as follows.

[C. Communication speed change setting process: Setting change from currently set communication speed of 100 Mbps to 10 Mbps]
Hereinafter, the communication speed change setting process by the communication speed switching instruction unit 140 will be described with reference to FIGS. 1, 7, and 9 again. This will be explained based on the following assumptions. It is assumed that the currently set communication speed of the gateway device 300-1 is 100 Mbps. The audio data transmission capacity for session number 2 is 80 Kbps. The total audio data transmission capacity is 3030 Kbps. The VoIP terminal 300-2 is busy with a session corresponding to session number 2.

  First, when the “BYE” message, which is a session termination request, is exchanged between the VoIP terminal 300-2 and the gateway device 300-1, the total capacity calculation unit 141 manages the session number 2 information as a session management. It deletes from the table 131 (FIG. 7: step S101). At this time, “audio data transmission capacity for each session” of 80 Kbps is also deleted from the session management table 131. Hereinafter, the gateway device that relays the call data for the session for which the end request is exchanged is also referred to as a call end gateway device.

  After the deletion, the total capacity calculation unit 141 calculates the total voice data transmission capacity 2950 Kbps by summing up the voice data transmission capacity for each session (FIG. 7: step S102). Next, the optimum communication speed determination unit 142 refers to the candidate communication speed table 132 (FIG. 4), and sets the voice data total transmission capacity 2950 Kbps calculated by the total capacity calculation unit 141 to “less than 3 Mbps”. Corresponding “candidate communication speed” 10 Mbps is selected as the optimum communication speed (FIG. 7: step S103).

  More specifically, the optimum communication speed determination unit 142 first determines that the currently set communication speed of the gateway device 300-1 is 100 Mbps by referring to the set communication speed table 133 (FIG. 5) (FIG. 9: step). S201, step S204). Next, the optimum communication speed determination unit 142 determines that the total voice data transmission capacity 2950 Kbps is less than 3 Mbps (FIG. 9: Step S202). Subsequently, the optimum communication speed determining unit 142 refers to the candidate communication speed table 132 and selects 10 Mbps as the optimum communication speed (FIG. 9: Step S203). When 10 Mbps is selected as the optimum communication speed (FIG. 9: step S206), the optimum communication speed determination unit 142 waits until a predetermined time elapses (FIG. 9: step S207). Specifically, the optimum communication speed determination unit 142 refers to the switching restriction table 134 (FIG. 6), and since the shortest switching interval for the gateway device 300-1 is 1 hour, the elapsed time after change setting is 1 Wait until time is up. The optimum communication speed determination unit 142 selects 10 Mbps as the optimum communication speed for the gateway device 300-1 after one hour has elapsed since the previous communication speed change setting.

  Thus, if the communication speed can be switched only after the elapse of the shortest switching interval, the session management is performed when the total voice data transmission capacity of the gateway device 300-1 is in the vicinity of a threshold value such as 3 Mbps. Even when session information is added to and deleted from the table 131 alternately, it is possible to prevent frequent switching between the optimum communication speed of 10 Mbps and 100 Mbps.

  The relay gateway device changing unit 143 refers to the set communication speed table 133 (FIG. 5), and the optimum communication speed 10 Mbps selected by the optimum communication speed determining unit 142 and the currently set communication speed 100 Mbps for the gateway device 300-1 are determined. Relay is determined to be different, and a gateway device (any one of 300-2 to 300-m) other than the gateway device 300-1 is used as a gateway device (relay gateway device) that relays call data for a session to be established thereafter. A gateway device change request is given to the call connection processing unit 120 (FIG. 7: Step S104).

  When the “BYE” message is exchanged between the VoIP terminal and the gateway device 300-1, the speed change setting requesting unit 144, for all the sessions that are establishing the call connection, It is determined that the session is completed (FIG. 7: Step S105). In this case, the speed change setting requesting unit 144 issues a speed change setting request for requesting a change setting in which the optimum communication speed of 10 Mbps is the currently set communication speed to the gateway device 300-1 (FIG. 7: Step S106).

  The speed change setting request is transmitted from the interface unit 110 to the gateway device 300-1 via the communication network 400. In response to the speed change setting request received by the communication IF unit 320, the communication speed control unit 310 of the gateway device 300-1 performs change setting with the optimum communication speed of 10 Mbps as the currently set communication speed. That is, the currently set communication speed is switched from 100 Mbps to 10 Mbps.

  The relay gateway device changing unit 143 changes the gateway device 300-1 after the speed change setting request is issued by the speed change setting requesting unit 144 or after receiving the communication speed change setting completion notification from the gateway device 300-1. A relay restriction release notification that the relay gateway device may be used is issued to the call connection processing unit 120. After receiving the relay restriction release notification, the call connection processing unit 120 can select the gateway device 300-1 as the relay gateway device.

The above is an example in which the current setting communication speed of the gateway device 300-1 is changed from 100 Mbps to 10 Mbps, that is, the current setting communication speed of the gateway device 300-1 is changed from high speed to low speed. Next, when the current setting communication speed of the gateway device 300-1 is changed from 100 Mbps to 1 Gbps, that is, when the current setting communication speed of the gateway device 300-1 is changed from low to high, the following is performed.

[D. Other communication speed change setting processing 1: Setting change from the currently set communication speed of 100 Mbps to 1 Gbps]
Hereinafter, the communication speed change setting process by the communication speed switching instruction unit 140 will be described with reference to FIGS. 1, 7, and 9 again. In the explanation, the following assumptions are made. The gateway device 300-1 has a currently set communication speed of 100 Mbps, and a total voice data transmission capacity of 3 Mbps or more and less than 30 Mbps. Further, “d. Other communication speed change setting process 1” corresponds to the case where the currently set communication speed is changed from low to high, so the processing procedure of “a. Communication speed change setting process” is performed. Is the basis.

  First, the VoIP terminal 200-1 transmits an “INVITE” message, which is a call connection request, to the gateway apparatus 300-1 via the SIP server 100. The gateway apparatus 300-1 transmits a “200 OK” message to the SIP server 100 as a response.

  The call connection processing unit 120 extracts the session information included in the “200 OK” message received by the interface unit 110, and adds this to the session management table 131 (FIG. 7: Step S101). The call connection processing unit 120 stores information included in the session information in association with each column of the session management table 131. The total capacity calculation unit 141 calculates “audio data transmission capacity for each session” from the information included in the session information.

  The total capacity calculation unit 141 adds the voice data transmission capacity of less than 30 Mbps for the newly established session to the current total voice data transmission capacity to obtain a voice data total transmission capacity of 30 Mbps or more including the voice data transmission capacity for the newly established session. Calculate (FIG. 7: Step S102).

  The optimum communication speed determination unit 142 refers to the candidate communication speed table 132 (FIG. 4), and “candidates” corresponding to “30 Mbps or more” that is a range including the total voice data transmission capacity calculated by the total capacity calculation unit 141. "Communication speed" 1 Gbps is selected as the optimum communication speed (FIG. 7: Step S103).

  More specifically, the optimum communication speed determination unit 142 selects the optimum communication speed according to the optimum communication speed selection processing routine shown in FIG. First, the optimum communication speed determination unit 142 refers to the set communication speed table 133 and determines that the currently set communication speed of the gateway device 300-1 is 100 Mbps (FIG. 9: Steps S201 and S204). Next, the optimum communication speed determination unit 142 determines that the total voice data transmission capacity is 30 Mbps or more (FIG. 9: Steps S205 and S208). Subsequently, the optimum communication speed determining unit 142 refers to the candidate communication speed table 132 and selects 1 Gbps as the optimum communication speed (FIG. 9: Step S209).

  The relay gateway device changing unit 143 determines that the optimum communication rate 1 Gbps selected by the optimum communication rate determining unit 142 is different from the currently set communication rate 100 Mbps, and gateway devices other than the gateway device 300-1 (newly established gateway device) A relay gateway device change request that uses (any one of 300-2 to 300-m) as a gateway device (relay gateway device) that relays call data for a session established after a newly established session is sent to the call connection processing unit 120. (FIG. 7: Step S104). The call connection processing unit 120 in response to the relay gateway device change request, in response to a call connection request issued from any one of the VoIP terminals 200-1 to 200-n thereafter, of the gateway devices 300-2 to 300-m. Either one is a relay gateway device. For example, priorities are assigned in advance to each of the gateway devices 300-1 to 300-m, and gateway devices (other than 300-1) to be used as relay gateway devices are selected in that order. By this processing, the gateway device 300-1 does not become a relay gateway device until at least the communication speed change setting processing routine ends.

  When the “BYE” message is exchanged between the VoIP terminal and the gateway device 300-1, the speed change setting requesting unit 144, for all the sessions that are establishing the call connection, It is determined that the session is completed (FIG. 7: Step S105). In this case, the speed change setting request unit 144 issues a speed change setting request for requesting a change setting in which the optimum communication speed of 1 Gbps is set as the currently set communication speed to the gateway device 300-1 (FIG. 7: Step S106). In this way, the speed change setting request unit 144 issues a speed change setting request when all the sessions for the gateway device 300-1 are completed.

  The speed change setting request is transmitted from the interface unit 110 to the gateway device 300-1 via the communication network 400. In response to the speed change setting request received by the communication IF unit 320, the communication speed control unit 310 of the gateway device 300-1 performs change setting with the optimum communication speed of 1 Gbps as the currently set communication speed. That is, the currently set communication speed is switched from 100 Mbps to 1 Gbps.

  The relay gateway device changing unit 143 changes the gateway device 300-1 after the speed change setting request is issued by the speed change setting requesting unit 144 or after receiving the communication speed change setting completion notification from the gateway device 300-1. A relay restriction release notification that the relay gateway device may be used is issued to the call connection processing unit 120. After receiving the relay restriction release notification, the call connection processing unit 120 can select the gateway device 300-1 as the relay gateway device.

The above is an example in which the current setting communication speed of the gateway device 300-1 is changed from 100 Mbps to 1 Gbps, that is, the current setting communication speed of the gateway device 300-1 is changed from high speed to low speed. Next, when the currently set communication speed of the gateway device 300-1 is maintained at 100 Mbps, that is, when the currently set communication speed of the gateway device 300-1 is maintained, the following is performed.

[E. Communication speed change setting process 2: When maintaining the currently set communication speed of 100 Mbps]
Hereinafter, the communication speed change setting process by the communication speed switching instruction unit 140 will be described with reference to FIGS. 1, 7, and 9 again. In the explanation, the following assumptions are made. It is assumed that the VoIP terminal 200-1 does not make a call connection request, the currently set communication speed of the gateway device 300-1 is 100 Mbps, and the total voice data transmission capacity is 3 Mbps or more and less than 30 Mbps. Further, “e. Other communication speed change setting process 2” corresponds to the case where the currently set communication speed is maintained, and therefore, the processing procedure of “b. Communication speed change setting process” is basic.

  First, since the call connection processing unit 120 does not receive a signal related to the “200 OK” message at the interface unit 110, the information in the session management table 131 is as it is (FIG. 7: step S101).

  Since the total capacity calculation unit 141 has not received the information of the newly established session, the total capacity calculation unit 141 calculates the current voice data total transmission capacity of 3 Mbps or more and less than 30 Mbps (FIG. 7: Step S102).

  The optimum communication speed determining unit 142 refers to the candidate communication speed table 132 (FIG. 4) and corresponds to “3 Mbps or more and less than 30 Mbps” that is a range including the total audio data transmission capacity calculated by the total capacity calculating unit 141. The “candidate communication speed” of 100 Mbps is selected as the optimum communication speed (FIG. 7: step S103).

  More specifically, the optimum communication speed determination unit 142 selects the optimum communication speed according to the optimum communication speed selection processing routine shown in FIG. First, the optimum communication speed determining unit 142 refers to the set communication speed table 133 (FIG. 5) and determines that the currently set communication speed of the gateway device 300-1 is 100 Mbps (FIG. 9: Steps S201 and S204). . Next, the optimum communication speed determination unit 142 determines that the total voice data transmission capacity is 30 Mbps or more and less than 300 Mbps. Further, the optimum communication speed determining unit 142 refers to the candidate communication speed table 132 and selects 100 Mbps as the optimum communication speed (FIG. 9: Steps S205 and S208).

  The relay gateway device changing unit 143 determines that the optimum communication rate 100 Mbps selected by the optimum communication rate determining unit 142 is the same as the currently set communication rate 100 Mbps. The relay gateway device changing unit 143 sends a relay gateway device change request to the gateway device 300-1 as a gateway device (relay gateway device) that relays call data for a session established after a newly established session, as currently set. This is given to the call connection processing unit 120 (FIG. 7: Step S104).

  Hereinafter, the processing in the case of maintaining the currently set communication speed is a series of processing without performing the processing of confirming the end of all sessions in FIG. 7 (FIG. 7: Step S105) and the speed change setting unit (FIG. 7: Step S106). Exit.

The above is an example of maintaining the currently set communication speed of the gateway device 300-1 at 100 Mbps, that is, maintaining the currently set communication speed of the gateway device 300-1. Next, when setting is changed from the currently set communication speed 1 Gbps to 100 Mbps of the gateway apparatus 300-1, that is, when changing from high speed to low speed, the setting is as follows.

[F. Other communication speed change setting process 3: Setting change from current setting communication speed 1 Gbps to 100 Mbps]
Hereinafter, the communication speed change setting process by the communication speed switching instruction unit 140 will be described with reference to FIGS. 1, 7, and 9 again. This will be explained based on the following assumptions. It is assumed that the currently set communication speed of the gateway device 300-1 is 1 Gbps, and the total voice data transmission capacity is 30 Mbps or more. Further, “f. Other communication speed change setting process 3” corresponds to the case where the currently set communication speed is changed from high speed to low speed, so the processing procedure of “c. Communication speed change setting process” is performed. Is the basis.

  First, when the “BYE” message, which is a session termination request, is exchanged between the VoIP terminal 300 and the gateway device 300-1, the total capacity calculation unit 141 obtains information on the session number related to the termination request. Delete from the session management table 131 (FIG. 7: step S101). At this time, “audio data transmission capacity for each session” is also deleted from the session management table 131. Hereinafter, the gateway device that relays the call data for the session for which the end request is exchanged is also referred to as a call end gateway device.

  After the deletion, the total capacity calculation unit 141 calculates the total voice data transmission capacity of less than 30 Mbps by summing the voice data transmission capacity for each session (FIG. 7: step S102). Next, the optimum communication speed determination unit 142 refers to the candidate communication speed table 132 (FIG. 4), and the “candidate communication speed” corresponding to the total voice data transmission capacity “less than 30 Mbps” calculated by the total capacity calculation unit 141. 100 Mbps is selected as the optimum communication speed (FIG. 7: Step S103).

  More specifically, the optimum communication speed determining unit 142 first determines that the currently set communication speed of the gateway device 300-1 is 1 Gbps by referring to the set communication speed table 133 (FIG. 5) (FIG. 9: Step). S201, step S204). Next, the optimum communication speed determination unit 142 determines that the total voice data transmission capacity is less than 30 Mbps (FIG. 9: Step S210). Subsequently, the optimum communication speed determining unit 142 refers to the candidate communication speed table 132 and selects 100 Mbps as the optimum communication speed (FIG. 9: Step S211). When the optimum communication speed determining unit 142 selects 100 Mbps as the optimum communication speed (FIG. 9: step S211), the optimum communication speed determining unit 142 stands by until a predetermined time elapses. Specifically, the optimum communication speed determination unit 142 refers to the switching restriction table 134 and waits until the elapsed time after change setting becomes the shortest switching interval based on the shortest switching interval for the gateway device 300-1. The optimum communication speed determination unit 142 selects 100 Mbps as the optimum communication speed for the gateway device 300-1 after the shortest switching interval has elapsed since the previous communication speed change setting. (FIG. 9: Step S212).

  Thus, if the communication speed can be switched only after the elapse of the shortest switching interval, the session management is performed when the total voice data transmission capacity of the gateway device 300-1 is in the vicinity of a threshold such as 30 Mbps. Even when session information is added to and deleted from the table 131 alternately, it is possible to prevent frequent switching between the optimum communication speeds of 100 Mbps and 1 Gbps.

  The relay gateway device changing unit 143 refers to the set communication rate table 133 and determines that the optimum communication rate 100 Mbps selected by the optimum communication rate determining unit 142 is different from the currently set communication rate 1 Gbps for the gateway device 300-1. , A gateway gateway device change request for using a gateway device (any one of 300-2 to 300-m) other than the gateway device 300-1 as a gateway device (relay gateway device) that relays call data for a session to be established thereafter Is provided to the call connection processing unit 120 (FIG. 7: step S104).

  When the “BYE” message is exchanged between the VoIP terminal and the gateway device 300-1, the speed change setting requesting unit 144, for all the sessions that are establishing the call connection, It is determined that the session is completed (FIG. 7: Step S105). In this case, the speed change setting request unit 144 issues a speed change setting request for requesting a change setting in which the optimum communication speed of 100 Mbps is the current setting communication speed to the gateway device 300-1 (FIG. 7: Step S106).

  The speed change setting request is transmitted from the interface unit 110 to the gateway device 300-1 via the communication network 400. In response to the speed change setting request received by the communication IF unit 320, the communication speed control unit 310 of the gateway device 300-1 performs change setting with the optimum communication speed of 100 Mbps as the currently set communication speed. That is, the currently set communication speed is switched from 1 GMbps to 100 Mbps.

  The relay gateway device changing unit 143 changes the gateway device 300-1 after the speed change setting request is issued by the speed change setting requesting unit 144 or after receiving the communication speed change setting completion notification from the gateway device 300-1. A relay restriction release notification that the relay gateway device may be used is issued to the call connection processing unit 120. After receiving the relay restriction release notification, the call connection processing unit 120 can select the gateway device 300-1 as the relay gateway device.

The above is an example of changing and setting the current setting communication speed of the gateway device 300-1 from 1 Gbps to 100 Mbps, that is, changing the current setting communication speed of the gateway device 300-1 from high speed to low speed. Next, when the currently set communication speed of the gateway device 300-1 is maintained at 1 Gbps, that is, when the currently set communication speed of the gateway device 300-1 is maintained, the following is performed.

[G. Other communication speed change setting process 4: When maintaining the currently set communication speed of 1 Gbps]
Hereinafter, the communication speed change setting process by the communication speed switching instruction unit 140 will be described with reference to FIGS. 1, 7, and 9 again. In the explanation, the following assumptions are made. The VoIP terminal 200-1 does not make a call connection request, the currently set communication speed of the gateway device 300-1 is 1 Gbps, and the total voice data transmission capacity is 30 Mbps or more. In addition, “g. Other communication speed change setting process 4” corresponds to the case where the currently set communication speed is maintained. Therefore, “b. Communication speed change setting process”, “e. Other communication speed change setting process”. The processing procedure “processing 2” is the basis.

  First, since the call connection processing unit 120 does not receive a signal related to the “200 OK” message at the interface unit 110, the information in the session management table 131 is as it is (FIG. 7: step S101).

  Since the total capacity calculation unit 141 has not received the information on the newly established session, the total capacity calculation unit 141 calculates a current voice data total transmission capacity of 30 Mbps or more (FIG. 7: Step S102).

  The optimum communication speed determination unit 142 refers to the candidate communication speed table 132 (FIG. 4), and “candidates” corresponding to “30 Mbps or more” that is a range including the total voice data transmission capacity calculated by the total capacity calculation unit 141. "Communication speed" 1 Gbps is selected as the optimum communication speed (FIG. 7: Step S103).

  More specifically, the optimum communication speed determination unit 142 selects the optimum communication speed according to the optimum communication speed selection processing routine shown in FIG. First, the optimum communication speed determining unit 142 refers to the set communication speed table 133 (FIG. 5) and determines that the currently set communication speed of the gateway device 300-1 is 1 Gbps (FIG. 9: Steps S201 and S204). . Next, the optimum communication speed determination unit 142 determines that the total voice data transmission capacity is 30 Mbps or more. Furthermore, the optimum communication speed determining unit 142 refers to the candidate communication speed table 132 and selects 1 Gbps as the optimum communication speed (FIG. 9: Step S210).

  The relay gateway device changing unit 143 determines that the optimum communication speed 1 Gbps selected by the optimum communication speed determining unit 142 is the same as the currently set communication speed 1 Gbps. The relay gateway device change unit 143 sends a relay gateway device change request to the gateway device 300-1 as a gateway device (relay gateway device) that relays call data for a session established after a newly established session, as currently set. This is given to the call connection processing unit 120 (FIG. 7: Step S104).

  Hereinafter, the processing in the case of maintaining the currently set communication speed is a series of processing without performing the processing of confirming the end of all sessions in FIG. 7 (FIG. 7: Step S105) and the speed change setting unit (FIG. 7: Step S106). Exit.

  The above is an example of maintaining the currently set communication speed of the gateway device 300-1 at 1 Gbps, that is, maintaining the currently set communication speed of the gateway device 300-1.

  As described above, the SIP server according to the present embodiment selects the optimum communication speed according to the voice data total transmission capacity for the gateway device calculated based on the session information included in the SIP message from the gateway device, and When all sessions for the gateway device are completed, a request to switch the communication speed to the optimum communication speed is issued to the gateway device. In other words, when the total amount of voice data handled by the gateway device is small, the communication speed is switched to a low speed to reduce power consumption. The effect that no interruption occurs is obtained. When the total amount of voice data handled by the gateway device increases, the communication speed is switched to high speed. In this case as well, the switching process is performed after all sessions are completed, so the call voice is interrupted. Does not occur. The gateway device changes the communication speed setting in response to a communication speed switching request from the SIP server. As described above, according to the SIP server of this embodiment, it is possible to suppress power consumption while appropriately changing the communication speed according to the total transmission amount of voice data.

1 SIP call connection system 100 SIP server device (SIP server)
110 Interface unit 120 Call connection processing unit 130 Storage unit 131 Session management table 132 Candidate communication speed table 133 Setting communication speed table 134 Switching restriction table 140 Communication speed switching instruction section 141 Total capacity calculation section 142 Optimal communication speed determination section 143 Relay gateway device Change unit 144 Speed change setting request unit 200-1 to 200-n VoIP terminals 300-1 to 300-m Gateway device 310 Communication speed control unit 320 Communication interface unit 400 Communication network

Claims (12)

In response to a call connection request from a VoIP communication terminal, one of the at least two gateway apparatuses is selected as a relay gateway apparatus, and a session is established between the VoIP communication terminal and the relay gateway apparatus according to the SIP protocol. A SIP server device,
A total capacity calculating unit that calculates a total transmission capacity of voice data for the relay gateway apparatus based on session information from the relay gateway apparatus;
An optimum communication speed determining unit for determining an optimum communication speed when the relay gateway device transmits call data based on the total voice data transmission capacity;
A speed change setting request unit that issues a speed change setting request to the relay gateway apparatus to the effect that the optimum communication speed should be a currently set communication speed when it is determined that all sessions for the relay gateway apparatus have been completed; A SIP server device comprising:   The total capacity calculation unit includes a session management table for storing a voice data transmission capacity for each session for each of the gateway devices, and a total value of the voice data transmission capacity for each session is set as the voice data total transmission capacity. The SIP server device according to claim 1.   The optimum communication speed determination unit includes a candidate communication speed table in which at least two candidate communication speeds are stored in advance for each of the gateway devices, and one of the candidate communication speeds corresponding to the voice data total transmission capacity is optimized. The SIP server device according to claim 1, wherein the SIP server device has a communication speed. A setting speed table for storing a current setting communication speed for the relay gateway device;
2. The relay gateway device changing unit according to claim 1, further comprising a gateway device other than the relay gateway device as the relay gateway device when it is determined that the optimum communication speed is different from the currently set communication speed. The SIP server device described.   2. The SIP server device according to claim 1, wherein the speed change setting request unit issues the speed change setting request only after a predetermined time has elapsed since the previous communication speed change setting.   3. The SIP according to claim 2, wherein the total capacity calculation unit calculates a voice data transmission capacity for each session based on a type of a voice encoding method and a packet transmission period included in the session information. Server device. At least two gateway devices, a VoIP communication terminal that selects one of the gateway devices as a relay gateway device in response to a call connection request from a VoIP communication terminal and issues the call connection request according to a SIP protocol; and A call connection system including a SIP server device that establishes a session with a relay gateway device,
The SIP server device
A total capacity calculation unit for calculating a total transmission capacity of voice data for the relay gateway apparatus based on session information from the relay gateway apparatus;
An optimal communication speed determination unit that determines an optimal communication speed at which the relay gateway device transmits call data based on the voice data total transmission capacity;
A speed change setting requesting unit that issues a speed change setting request to the relay gateway apparatus indicating that the optimum communication speed should be a currently set communication speed when it is determined that all sessions for the relay gateway apparatus have been completed; Including
The gateway device is
A communication speed control unit that sets the optimum communication speed as the currently set communication speed in response to the speed change setting request;
And a relay unit that relays the call data at the currently set communication speed.   The total capacity calculation unit includes a session management table for storing a voice data transmission capacity for each session for each of the gateway devices, and a total value of the voice data transmission capacity for each session is set as the voice data total transmission capacity. The SIP server device according to claim 7.   The optimum communication speed determination unit includes a candidate communication speed table in which at least two candidate communication speeds are stored in advance for each of the gateway devices, and one of the candidate communication speeds corresponding to the voice data total transmission capacity is optimized. 8. The SIP server device according to claim 7, wherein a communication speed is set. A setting speed table for storing a current setting communication speed for the relay gateway device;
8. The relay gateway device changing unit according to claim 7, further comprising a gateway device other than the relay gateway device that uses the gateway device as the relay gateway device when it is determined that the optimum communication speed is different from the currently set communication speed. The SIP server device described.   8. The SIP server apparatus according to claim 7, wherein the speed change setting request unit issues the speed change setting request only after a predetermined time has elapsed since the previous communication speed change setting.   9. The SIP according to claim 8, wherein the total capacity calculation unit calculates a voice data transmission capacity for each session based on a type of a voice encoding method and a packet transmission period included in the session information. Server device.

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