JP2007081713A - Ip phone set and ip phone system, and time acquisition method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the time deviation of communication packets between IP phones, without cost increase for the system as a whole, and without the need for an NTP server over a network. <P>SOLUTION: A time acquisition section 202 of an IP phone control section 203 acquires time information contained in a message received from a SIP (Session Initiation Protocol) server 103 for controlling call connection via a LAN I/F section 201 connected to the IP network. A time setting section 204 in a time control section 205 for controlling a RTC (Real-Time Clock) 206 sets the acquired time information to the RTC 206 as the time information managed by own IP phone. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an IP telephone apparatus, an IP telephone system, and a time acquisition method for making a call via an IP network.

  In recent years, with the rapid spread of the Internet, attention has been paid to IP telephone devices (hereinafter referred to as “IP telephones”) capable of making free calls between remote telephone devices and low-cost calls or between registered member IP telephone devices. Has been.

  Various forms of IP telephone service have been proposed. For example, a SIP (Session Initiation Protocol) server arranged in an IP network uses a call control protocol SIP (IETF standard RFC3261) to establish a call connection between an IP telephone serving as a calling terminal and an IP telephone serving as a receiving terminal. After the connection, the IP telephones transmit and receive voice packets via the IP network to realize a real-time call.

  When packet communication is performed between such IP telephones via the IP network, since the IP network has no bandwidth guarantee, the IP network is congested and the quality is poor. Since there is no guarantee of reaching in order, communication may be hindered.

  FIG. 6 is a block diagram showing a configuration of a conventional IP telephone apparatus.

  The IP telephone 1 shown in FIG. 6 controls the time of an IP telephone control unit 3, an RTC (Real Time Clock) 4, and an RTC 4 that perform communication in an IP network via the LAN I / F unit 2 and the LAN I / F unit 2. And a user time setting unit 6 for setting the time of the RTC 4 via the clock control unit 5 by a user operation.

  In the IP phone 1, the clock control unit 5 reads the time of the RTC 4 and provides the time information to the IP phone control unit 3. Upon receiving this time information, the IP telephone control unit 3 describes the time in the header of the call control protocol, and takes the consistency of packets transmitted and received via the LAN I / F unit 2.

  FIG. 7 is a sequence diagram for explaining the operation of the conventional IP telephone apparatus. IP phone A and IP phone B shown in this figure have the same configuration as IP phone 1 shown in FIG.

  As shown in FIG. 7, in the conventional IP telephone device, after the terminal is turned on, each IP telephone device (IP phone A and IP phone B shown in FIG. 7) responds to the occurrence of the set time lag. The time is manually adjusted by the user. In general, time information of an IP phone is manually adjusted as necessary by the user before sending a “Register” command for registration from the IP phone to the SIP server after the power is turned on. The

  Then, after receiving the “200 OK” command returned from the SIP server that transmitted the “Register” command, IP phone A adds the time information from the manually set RTC 4 to the response packet, and An “INVITE” command is transmitted to the server.

  The SIP server that has received the “INVITE” command from IP phone A transmits “INVITE” to IP phone B, and then starts a call by transmitting and receiving RTP packets. Since RTP packets place importance on real-time characteristics, it is common to use UDP as the packet type, and since UDP does not check whether the packet has arrived at the other side, in such a communication protocol, Each IP telephone confirms and adjusts the coincidence of voice time series by comparing time information of packets received immediately before.

  In such an IP phone, time information is set individually for each IP phone, and therefore the same and accurate time information cannot always be set in each IP phone. For this reason, there is a difference in the time information set in the packet between the IP telephones that perform communication, and when the packet arrives on the receiving side when the network is congested, an error occurs in the time information described in the packet, This may cause a problem that the time series adjustment cannot be corrected.

On the other hand, for example, as shown in Patent Document 1, a shared NTP (Network Time Protocol) server that performs time adjustment on a network is arranged, and each device on the network is provided with an NTP client protocol. It is known that time information between devices is made the same, and a shift in packet time information by the devices is avoided.
JP 2004-199366 A

  However, in the above configuration, since it is necessary to provide the NTP server equipment and the device with the NTP client protocol, there is a problem that the system as a whole leads to a total cost increase. It was not a good solution.

  The present invention has been made in view of the above points, and can eliminate the time lag of communication packets between devices without requiring an NTP server on the network and without increasing the cost of the entire system. An object is to provide an IP telephone device.

  The present invention relates to an IP telephone apparatus connected via an IP network, and includes time measuring means for measuring time information managed by the own apparatus, and time information included in a message received from a management server that controls call connection. And a time setting means for setting the acquired time information in the time measuring means.

  According to the IP telephone apparatus of the present invention, it is possible to simply adjust the time of the own apparatus without requiring an NTP server on the network, without increasing the cost of the entire system, and to communicate packets between the apparatuses. Can be eliminated.

  A first aspect of the present invention is an IP telephone apparatus connected via an IP network, in a message received from a time measuring means for measuring time information managed by the own apparatus and a management server for controlling call connection. The time information acquisition means for acquiring the time information included in the information and the time setting means for setting the acquired time information in the time measurement means are employed.

  According to this configuration, since the time information included in the message received from the management server that controls the call connection is set as the time information managed by the own device, the cost of providing an NTP server on the network is also necessary. The time of the own device can be easily adjusted. That is, since the time information of a specific management server is acquired, the counterpart device connected via the IP network can be set to the same time information. Therefore, the same time information can be described in a packet between IP telephone devices of the same IP network. Also, based on the time information of the own device, it is possible to arrange the received packets in the order of transmission and realize voice communication without any trouble.

  Therefore, an NTP server is not required on the network, and the time of the own device can be adjusted easily and automatically without increasing the cost of the entire system, and the time difference of communication packets between devices can be eliminated. Can do.

  According to a second aspect of the present invention, in the IP telephone apparatus according to the first aspect, the message received from the management server is a response message to the terminal registration request of the own apparatus.

  According to this configuration, at the time of terminal registration, the time information of the management server can be acquired and set as time information managed by the own device.

  According to a third aspect of the present invention, in the IP telephone apparatus according to the first aspect, there is provided a control unit that uses time information acquired from the message and set in the time measuring unit as time information of a packet to be transmitted. Take.

  According to this configuration, since packets sent from any device are set based on the time information of the management server, packets sent to the IP network are packets received by the counterpart device due to congestion of the IP network. Even when there is a deviation in the arrival order, it is possible to realize communication without defects by arranging the received packets in the order of transmission with reference to the time information described in the packets.

  According to a fourth aspect of the present invention, there is provided an IP telephone system including a plurality of IP telephone apparatuses that perform a call via an IP network, and a management server that controls call connection of the IP telephone apparatus. A time measuring means for measuring time information, a time information acquiring means for acquiring time information included in a message received from the management server, and a time setting means for setting the acquired time information in the time measuring means. Then, the management server has a configuration having transmission means for inserting time information into a call connection message and transmitting it to the IP telephone apparatus.

  According to this configuration, the IP telephone apparatus receives the call connection message in which the time information transmitted from the management server that controls the call connection is inserted, acquires the time information included in the received message, It can be set as the time information of the own device, and there is no need to provide an NTP server on the IP network, and the time can be easily adjusted in an IP telephone device that performs communication via the IP network. That is, in order to acquire the time information of a specific management server, the counterpart IP telephone device connected via the IP network can be set to the same time information. Therefore, the same time information can be described in a packet among a plurality of IP telephone apparatuses in the same IP network. Also, based on the time information of the IP telephone apparatus, it is possible to arrange received packets in the order of transmission and realize voice communication without any trouble. Therefore, an NTP server is not required on the IP network, and the time of the communication packet between the IP telephone devices can be adjusted easily and automatically by adjusting the time of the own device without increasing the cost of the entire system. Can be resolved.

  According to a fifth aspect of the present invention, there is provided a time acquisition method for an IP telephone apparatus connected via an IP network, the time information included in a message received from a management server that controls call connection of the IP telephone apparatus. The acquired time information is set as the time information of the own device.

  According to this method, in the IP telephone apparatus, the time information included in the message received from the management server that controls the call connection of the IP telephone apparatus is acquired, and the acquired time information is set as the time information of the own apparatus. In addition, there is no need for providing an NTP server on the network, and the time of the own device can be easily adjusted. That is, since the time information of a specific management server is acquired, the counterpart device connected via the IP network can be set to the same time information. Therefore, the same time information can be described in a packet between IP telephone devices of the same IP network. Also, based on the time information of the own device, it is possible to arrange the received packets in the order of transmission and realize voice communication without any trouble.

  Therefore, an NTP server is not required on the IP network to be connected for communication, and the time of the own device is simply and automatically adjusted without increasing the cost of the entire system, and communication between IP telephone devices is performed. The deviation of packet time information can be eliminated.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of an IP telephone system to which an IP telephone apparatus according to an embodiment of the present invention is applied. In the IP telephone system 100 shown in FIG. 1, a plurality of IP telephone apparatuses (hereinafter referred to as “IP telephones”) 101 and 102 and an IP communication server (SIP server) 103 are connected to each other via an IP network 104. ing. The IP telephone system may be configured by connecting three or more IP telephone devices without being limited to the configuration shown in FIG.

  The IP phone 101 (102) has a function capable of performing a voice call with another IP phone or the like via the IP network 104.

  An IP communication server (hereinafter referred to as “SIP server”) 103 responds to a registration request or a call connection request from an IP phone (for example, IP phone 101) connected to the IP network 104, and receives a call destination IP phone ( For example, call connection control is executed with the IP telephone 102) based on the SIP protocol, and transmission / reception of voice data to / from the IP telephone connected to the call is controlled. Further, the SIP server 103 adds the time information managed by the SIP server 103 to the transmission information to be transmitted to the IP phones 101 and 102 based on the SIP protocol, and transmits it. For example, the SIP server 103 describes time information in the header of a message in a packet to be transmitted to the IP phones 101 and 102 and transmits the message.

  FIG. 2 is a block diagram showing a main configuration of IP phone 101 according to the embodiment. The IP phone on the IP network 104 (see FIG. 1) has the same configuration as the IP phone 101. Here, since IP phone 102 also has the same configuration as IP phone 101, description thereof is omitted.

  In FIG. 2, the IP phone 101 is mainly configured by a LAN I / F unit 201, an IP phone control unit 203 having a time acquisition unit 202, a clock control unit 205 having a time setting unit 204, an RTC 206, and the like.

  The LAN I / F unit 201 has an interface function for connecting to the IP network 104 (see FIG. 1), and performs transmission / reception of commands and voice packets based on SIP under the control of the IP telephone control unit 203. Note that packets transmitted / received via the LAN I / F unit 201 correspond to voice packets whose transmission / reception is controlled by the IP telephone control unit 203, and if the IP telephone control unit 203 can control transmission / reception of video packets. In addition to audio packets, video packets can be transmitted and received.

  Here, the IP telephone control unit 203, based on the SIP protocol, registration processing for registering the current location of the own device, calling / incoming processing with the other IP phone (for example, the IP phone 102), call termination Controls processing / retransmission processing and the like. The IP telephone control unit 203 controls transmission / reception of voice packets with a partner IP telephone to which a call is connected based on a VoIP (Voice over Internet Protocol) protocol.

  In the IP telephone control unit 203, the time acquisition unit 202 acquires the time information of the SIP server from the response message from the SIP server 103 (see FIG. 1) received via the LAN I / F unit 201. For example, the IP telephone control unit 203 transmits a “Register” command to the SIP server 103 after power-on of the IP telephone 101 based on the SIP protocol, and the time from the time information header of the response message in the response “200 OK” command. Get information.

  The time acquisition unit 202 outputs the acquired time information to the time setting unit 204 of the clock control unit 205.

  The clock control unit 205 controls the time of the RTC 206, and outputs time information to the IP phone control unit 203 under the control of the IP phone control unit 203.

  The time setting unit 204 sets the time of the RTC 206 according to the time of the SIP server 103 based on the information from the time acquisition unit 202.

  Next, the time setting process of IP phone 101 according to the present invention will be described.

  FIG. 3 is a flowchart for explaining the operation of the IP telephone apparatus according to the embodiment.

  First, after power is turned on in the IP phone, in step S1, the IP phone 101 sends a “Register” command to the SIP server 103 (see FIG. 1) in order to register itself based on the SIP protocol. Send. Specifically, the IP telephone control unit 203 transmits a “Register” command based on the SIP protocol via the LAN I / F unit 201 to perform registration processing.

  In step S 2, IP phone 101 determines whether or not a response message “200 OK” command from SIP server 103 has been received. That is, if the IP telephone control unit 203 receives a response message including the “200 OK” command via the LAN I / F unit 201, it is determined that the IP telephone control unit 203 has been registered in the SIP server 103, and the process proceeds to step S3. If it is not received in S2, it is determined that there is no response from the SIP server 103 or connection failure, resulting in communication failure.

  The response message transmitted from the SIP server 103 has a time header based on time information managed by the SIP server 103. That is, the SIP server adds time information to the response message transmitted from the SIP server and transmits the response message.

  In the case of communication failure, the IP phone repeatedly transmits a “Register” command to the SIP server, receives a response message including a “200 OK” command, and continues until the registration process is completed. Also good.

  In step S3, the IP phone acquires time information from the response message from the SIP server. Specifically, in step S 3, in IP phone control unit 203, time acquisition unit 202 acquires time information from a response message including a “200 OK” command from the SIP server obtained via LAN I / F unit 201. The process proceeds to step S4.

  In step S4, the IP telephone control unit 203 outputs the acquired time to the time setting unit 204 of the clock control unit 205 from the time acquisition unit 202 that has acquired the time information, and the time setting unit 204 sets the time of the RTC 206 as follows. Set to the acquired time information.

  FIG. 4 is a sequence diagram showing an example of an operation executed between IP telephones of a system to which the IP telephone apparatus according to the embodiment is applied.

  Here, a series of operations in which IP phone 101 makes a call with IP phone 102 via SIP server 103 is shown.

  First, as shown in FIG. 4, after the power is turned on, IP phone 101 and IP phone 102 each transmit a “Register” command to SIP server 103 that is an IP management server (step S11). , S13). Then, when the SIP server 103 understands and accepts the “Register” command request transmitted from each of the IP phones 101 and 102, the SIP server 103 receives “200 OK” for the IP phone that has transmitted the “Register” command request. Is transmitted (steps S12 and S14). At this time, the SIP server 103 describes the time information managed by the SIP server 103 in the header of the response packet message including “200 OK” to be transmitted.

  Upon receiving this, the IP phone automatically sets the clock from the time information header of the response message, and describes the acquired time information in a packet (here, the message of the “INVITE” command) sent from the IP phone to the SIP server. .

  FIG. 5 is a diagram showing an example of a message in a packet used in the time setting operation in the IP telephone apparatus according to the embodiment.

  As shown in FIG. 5, the time information (“Date: Wed.20 Nov 2005 03:45:15 GMT”) of the message in the response packet including the “200 OK” command for the “Register” request is acquired and the clock control is performed. The unit 205 sets and updates the time information of the IP phone. In step S15, when the IP phone transmits a packet including the “INVITE” command to make a call with another IP phone, the IP phone control unit 203 performs steps S3 to S4 (see FIG. 3). Further, the clock control unit 205 sends time data (“Date: Wed.20 Nov 2005 04:50” based on the time information of the SIP server 103 set in the registration process starting with “Register” transmission in the clock control unit 205. : 20 GMT ”is acquired and described in the time header of the packet of the“ INVITE ”command to be transmitted Steps S16 to S25 are general call control and call processing based on the SIP protocol, and description thereof will be omitted.

  As described above, the time indicated by the time information included in the message received from the SIP server 103 that controls the call connection is set as the time information managed by each of the IP phones 101 and 102. In addition to providing an NTP server, the IP phones 101 and 102 do not need to be provided with an NTP client protocol, and the time is easily adjusted in the IP phones 101 and 102 without affecting the processing load and CPU cost associated therewith. It can be carried out.

  That is, since the time information of a specific management server (here, the SIP server 103) is acquired, the counterpart device connected via the IP network 104 can be set to the same time information. The same time information between 101 and 102 can be described in the communication packet. Further, it is possible to realize packet communication such as voice, in which received packets are arranged in the order of transmission based on the time information of the own device, and there is no problem in time information shift.

  In the present embodiment, the IP phone obtains time information from a response message transmitted from the SIP server in response to a “Register” command sent to the SIP server after power-on, and the IP phone based on the obtained time information. It is assumed that the time managed by the telephone is set. However, the present invention is not limited to this, and the IP telephone periodically sends a “Register” command and responds to these “Register” commands from the SIP server (here. Then, every time “200 OK” is transmitted, the time of the IP phone may be updated based on the time information of the response packet.

  Alternatively, the time information may be acquired from the message of the “INVITE” command sent from the SIP server to the IP telephone side, and updated by setting the time managed by the IP telephone.

  In this way, the IP phone obtains the current time from the time information header described in the message transmitted from the call control server of the call control protocol (SIP in this case), and in detail based on the obtained time. Updates and sets the RTC time of its own device in accordance with the acquired time. Communication is performed by inserting the RTC time into a transmission packet.

  The IP phone according to the present embodiment is assumed to communicate using the SIP protocol. However, the present invention is not limited to this, and includes time information transmitted by a server used for call connection in an IP network. Any call control protocol may be used as long as time information is acquired from the response message and the acquired time information is set as the time information of the terminals belonging to the IP network.

  Therefore, in this embodiment, it is not necessary to increase the cost due to the deployment of the NTP server on the network and the provision of the NTP server protocol. Can be reduced or eliminated.

  And in order to acquire the time information of a specific IP communication server, the same time information between the same IP telephones can be described in a packet.

  In the present embodiment, the time information acquired from the response message from the server on the IP telephone side may be used for clock display, incoming call history, answering machine, and the like. Furthermore, the IP phone may be configured to further include a communication history log collection unit for countermeasures against troubles such as congestion on the network, and the time information acquired by the time acquisition unit may be recorded.

  The IP telephone apparatus according to the present invention has the effect of eliminating the time information shift of communication packets between apparatuses without requiring an NTP server on the network and without increasing the cost of the entire system. In particular, it is useful as an IP telephone apparatus that performs communication based on SIP.

The figure which shows the structure of the IP telephone system to which the IP telephone apparatus which concerns on one embodiment of this invention is applied. The block diagram which shows the principal part structure of the IP telephone apparatus which concerns on the same embodiment Flow chart for explaining the operation of the IP telephone apparatus according to the embodiment The sequence diagram which shows an example of the operation | movement performed between IP telephones of the system to which the IP telephone apparatus which concerns on the embodiment is applied The figure which shows an example of the message of the packet used with the time setting operation | movement in the IP telephone apparatus which concerns on the embodiment Block diagram showing the configuration of a conventional IP telephone device Sequence diagram for explaining the operation of a conventional IP telephone apparatus

Explanation of symbols

100 IP telephone system 101, 102 IP telephone 103 SIP server (management server)
DESCRIPTION OF SYMBOLS 104 IP network 202 Time acquisition part 203 IP telephone control part 204 Time setting part 205 Clock control part 206 RTC (time measuring means)

Claims (5)

An IP telephone device connected via an IP network,
A time measuring means for measuring time information managed by the own device;
Time information acquisition means for acquiring time information included in a message received from a management server that controls call connection;
Time setting means for setting the acquired time information in the time measuring means;
An IP telephone apparatus comprising:   2. The IP telephone apparatus according to claim 1, wherein the message received from the management server is a response message to the terminal registration request of the own apparatus.   2. The IP telephone apparatus according to claim 1, further comprising a control unit that uses time information acquired from the message and set in the time measuring unit as time information of a packet to be transmitted. An IP telephone system comprising a plurality of IP telephone apparatuses that perform calls over an IP network, and a management server that controls call connection of the IP telephone apparatus,
The IP telephone device measures time information for measuring time information;
Time information acquisition means for acquiring time information included in a message received from the management server;
Time setting means for setting the acquired time information in the time measuring means,
The IP telephone system, wherein the management server includes transmission means for inserting time information into a call connection message and transmitting it to the IP telephone apparatus. A time acquisition method for an IP telephone device connected via an IP network,
Obtain time information included in the message received from the management server that controls the call connection of the IP telephone device,
A time acquisition method characterized in that the acquired time information is set as time information of the own device.

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