JP4094316B2 - Internet telephone system and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an Internet telephone system and method for performing voice communication via a gateway between a plurality of telephone terminals connected to a public subscriber telephone network and a plurality of IP terminals connected to an IP network. The present invention relates to an Internet telephone system and method for switching to another IP terminal during a call between the IP terminal and the IP terminal.
[0002]
[Prior art]
Conventionally, when a call is made between a terminal connected to the public telephone network (PSTN) side and an IP terminal connected to an IP (Internet Protocol) network, a one-to-one call is made via a gateway.
[0003]
[Problems to be solved by the invention]
However, in the call between the prior art PSTN and the IP network, when a call is made to another IP terminal during the call, the call must be disconnected and then the other IP terminal must be called. There is a point. That is, when a user using a PSTN side terminal wants to make a call with another IP network side terminal during a call with the IP network side terminal, the telephone lines corresponding to the number of corresponding IP network side terminals are physically connected. There is a problem that it is necessary.
[0004]
In view of the above problems, an object of the present invention is to enable a plurality of IP terminals to make a call to one terminal on the PSTN side.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present inventionThe Internet telephone system is an Internet telephone system in which voice communication is performed via a gateway between a plurality of telephone terminals connected to a public subscriber telephone network and a plurality of IP terminals connected to an IP network.
  The gateway for establishing a call connection between the telephone terminal and the plurality of IP terminals;
  A control device for the gateway that controls the gateway, and
    The gateway is
      When a push button signal is received from the telephone terminal during a call during a call between the telephone terminal and the IP terminal,From the push button signalNew connectionExtracting means for extracting the telephone number of the IP terminal;
      ExtractedNew connectionIP terminalPhone numberVs.Requesting the control device to confirm the validity of the new connection to be received, and receiving the result of confirming the validity of the telephone number and the IP address of the new connection destination from the control device, the IP address of the new connection destination Send a packet with theThe call connection is made and the extracted from the IP terminal during the callNew connectionA switching means for switching to an IP terminal to make a call state;
    Have
    The controller is
      The validity of the connection corresponding to the telephone number inquired from the gateway is confirmed, and the validity confirmation result and the IP address of the connection destination corresponding to the telephone number are transmitted to the gateway. Based on notificationManagement means for managing, for each telephone terminal, connection information between the plurality of IP terminals that have made a call connection from the telephone terminal
  It is characterized by having.
[0009]
Furthermore,aboveIn the Internet telephone system, the connection information isEach of the plurality of IP terminals that have made a call connection from the telephone terminal,IP address and, CorrespondingA terminal identification number including a telephone number;With the telephone terminalConnection status indicating whether the call is on hold or on hold,
  The management means includesBased on the notification from the gateway, the connection status of each of the plurality of IP terminals that have made a call connection from the telephone terminal is updated.It is characterized by that.
[0010]
Also,In the above internet telephone system, the switching means switches when receiving a push button signal or an on-hook signal carrying a special character indicating switching from the telephone terminal in the middle of a call between the telephone terminal and the IP terminal. An inquiry is made to the control device about connection destination information, and an IP terminal connected to the telephone terminal is determined based on connection destination information indicating switching to the pending IP terminal searched from the connection information managed by the management means. SwitchIt is characterized by that.
  In the Internet telephone system, the switching unit transmits a call setting packet set with a new connection destination IP address received from the control device, and receives a response from the new connection destination IP terminal. The control device is notified of a change in connection state.
[0014]
Also,Of the present inventionThe Internet telephone method is an Internet telephone method for performing voice communication via a gateway between a plurality of telephone terminals connected to a public subscriber telephone network and a plurality of IP terminals connected to an IP network,
  The gateway for establishing a call connection between the telephone terminal and the plurality of IP terminals;
  A terminal identification number including the IP address of the connection destination and the telephone number of the IP terminal of the connection destination;
  A terminal identification number including an IP address of the IP terminal of the connection destination and a telephone number of the IP terminal of the connection destination;
  A gateway control device for managing connection information including a connection state of the IP terminal indicating whether the call is on hold or on hold for each of the telephone terminals; and
  The gateway is
    When a push button signal is received from the telephone terminal during a call during a call between the telephone terminal and the IP terminal,From the push button signalNew connectionExtracting the telephone number of the IP terminal;
    ExtractedNew connectionIP terminalPhone numberVs.Requesting the control device to confirm the validity of the new connection, send the confirmation of the validity of the telephone number and the IP address of the new connection destination to the new connection destinationMake a call connection,The extracted from the IP terminal during the callNew connectionSwitch to an IP terminal and put it in a talking state,
    The controller isThe validity of the connection corresponding to the telephone number inquired from the gateway is confirmed, and the validity confirmation result and the IP address of the connection destination corresponding to the telephone number are transmitted to the gateway. Management of connection information between a plurality of IP terminals that have made a call connection from the telephone terminal based on the notification for each telephone terminalIt is characterized by that.
[0015]
Also,In the Internet telephone method, the connection information includes a terminal identification number including an IP address and a corresponding telephone number of each of the plurality of IP terminals that have made a call connection from the telephone terminal, and the telephone terminal. Connection status indicating whether the call is on hold or on hold,
The management means updates the connection status of each of the plurality of IP terminals that have made a call connection from the telephone terminal based on the notification from the gateway, whether the call is on hold or on hold.It is characterized by that.
  In the Internet telephone method, when the switching means receives a push button signal or an on-hook signal carrying a special character indicating switching from the telephone terminal during the call during the call between the telephone terminal and the IP terminal. , Inquiring of the connection destination information to be switched to the control device, and based on the connection destination information indicating switching to the pending IP terminal retrieved from the connection information managed by the management means, the IP of the connection destination with the telephone terminal It is characterized by switching terminals.
  In the Internet telephone method, the switching unit transmits a call setting packet in which a new connection destination IP address received from the control device is set, and receives a response from the new connection destination IP terminal. The control device is notified of a change in connection state.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, a first embodiment of the present invention will be described with reference to the drawings.
[0017]
Referring to FIG. 1, there is shown a configuration example of a system according to the first embodiment, which includes a PSTN 910 that is a public telephone network and an IP network 920 that is an IP (Internet Protocol) network. A terminal 1 that is a telephone terminal compatible with a plurality of public subscriber telephone networks, an IP terminal 4 that is a plurality of Internet terminals (in the example, IP terminals 4-1 and 4-2), and an IP terminal 4 and a terminal 1 MG2 that is a media gateway that performs protocol conversion between voice data and the like, and MGC3 that controls MG2 and manages connection information between IP terminal 4 and terminal 1. Note that terminal 1, MG2 and MGC3 are connected to PSTN 910, and MG2, MGC3 and IP terminal 4 are connected to IP network 920.
[0018]
The MG 2 in FIG. 1 includes a call connection unit 202 that controls call connection, a connection destination switching unit 203 that performs control to switch connection destinations, and a communication unit 201 that performs communication with the MGC 3.
[0019]
When a call connection is made between the terminal 1 and the IP terminal 4, the call connection unit 202 in FIG. 1 digitizes the voice (in this case, an analog signal) from the PSTN 910, and places the digitized voice data on the packet. The terminal 1 connected to the PSTN 910 receives the packet carrying the voice data from the IP network 920 and transmits it to the IP terminal 4 connected to the IP network 920. Means for transmitting to. In addition, the call connection unit 202 includes means for switching the IP terminal 4 by performing call connection with a packet to the IP terminal 4 to be switched according to an instruction from the connection destination switching unit 203. In this case, the packet flowing in the IP network 920 is exchanged by a UDP packet used based on the VoIP (Voice over IP) protocol.
[0020]
1 receives the PB signal from the PSTN 910 via the call connection unit 202 and extracts the destination telephone number, the MGC 3 confirms the validity of the destination telephone number and calls Means for connecting the connection unit 202 to the other party's telephone number and making a call, means for extracting the other party's telephone number from the PB signal, and a PB signal carrying a special character indicating switching during the call (connection destination switching) Notification), based on the connection destination state information 303 managed by the MGC 3, the call connection unit 202 is switched to the original destination IP terminal 4 (returning to the original connection), and during the call When the on-hook signal (connection destination switching notification) is received, the call connection unit 202 is switched to the original destination IP terminal 4 based on the connection destination state information 303 managed by the MGC 3 (returns to the original connection). hand With the door.
[0021]
The MGC 3 in FIG. 1 manages the connection state from the PSTN 910 to the IP network 920 direction or from the IP network 920 to the PSTN 910 direction. The MGC 3 includes a communication unit 301 that performs communication with the MG 2, the PSTN 910, or the IP network 920, a connection state management unit 302 that manages a connection state between current terminals, and a connection destination state that stores the connection state Information 303.
[0022]
Referring to FIG. 2, a configuration example of the connection destination state information 303 is shown, which is assigned as a table to an area in a memory (for example, RAM) not shown. The connection destination state information 303 is the terminal identification of the terminal 1 (PSTN 910 side) so that it can be managed for each terminal on the PSTN 910 side when a call connection is made between the terminal 1 accommodated in the PSTN 910 and the IP terminal 4. Number, the terminal identification number of the connection destination 1, the connection state of the connection destination 1 (indicating whether the call is on hold, on hold, or not connected), the terminal identification number of the connection destination 2 and the connection state of the connection destination 2 (call Medium, on hold, or indicating no connection), ... the terminal identification number of the connection destination N (N = represents a positive integer) and the connection status of the connection destination N (busy, on hold, or not connected) Is shown). When the terminal 1 is disconnected, the connection information of the disconnected terminal 1 registered in the connection destination state information 303 is deleted by the connection state management unit 302. Note that the connection destination 1 is information on the partner on the IP network side that is connected first, and the connection destination 2 and subsequent information is information on the calling partner that called a partner different from the partner on the call. Further, the PSTN side terminal identification number of the connection destination state information 303 indicates the telephone number of the terminal 1, the terminal identification numbers of the connection destination 1 and the connection destination 2 are the connection destination IP address of the IP network 920, the telephone number of the IP terminal 4, and the like. Indicates information including
[0023]
The connection state management unit 302 in FIG. 1 registers the terminal identification number of the IP terminal 4 switched by MG2 when the destination telephone number is on the PB signal, and also displays the connection state of the IP terminal 4 switched by MG2. The means for setting the connection status of the IP terminal 4 during the call and setting the connection status of the IP terminal 4 during the call on hold, and the connection status of the IP terminal 4 restored by the MG 2 when the special character is on the PB signal. And setting means for setting the connection status of other IP terminals 4 to “pending”.
[0024]
Note that the call for MG2 described in the present invention is made from the PSTN 910 side, and the terminal that implements the call is the terminal 1 in FIG. 1, and the IP side terminal that finally receives the call from the terminal 1 is the IP terminal. A terminal 4-1 and an IP terminal 4-2 are used.
[0025]
Although the configuration example of the embodiment has been described above, the communication unit 201 and the communication unit 301 in FIG. 1 are well known to those skilled in the art and are not directly related to the present invention, and thus the detailed configuration is omitted. To do.
[0026]
In the configuration example of the above embodiment, the PSTN 910, the MG2, and the IP network 920 are all configured by one for convenience of the notation in FIG. 1, but the number is not limited, and one PSTN ( Alternatively, a network configuration of one (or a plurality) of IP networks via a plurality (or one) MG from a plurality of PSTNs) is possible.
[0027]
Next, the operation of the first exemplary embodiment of the present invention will be described with reference to FIGS.
[0028]
The operation when switching from a call in which MG2 and MGC3 in FIG. 1 are connected to a new call will be described with reference to the flowchart in FIG.
[0029]
First, since the caller of the terminal 1 makes a call to the IP terminal 4-1, when the connection state management unit 302 of the MGC 3 receives the telephone number of the other party via the communication unit 301, the call connection unit 202 of the MG 2 On the other hand, a communication path is set between the terminal 1 and the IP terminal 4-1. Further, as the connection information, the telephone number of the terminal 1 is set in the PSTN side terminal identification number field of the connection destination state information 303. This is managed by setting the IP address and telephone number of the IP terminal 4-1 in the terminal identification number column of the connection destination 1 and setting “busy” in the connection status column.
[0030]
Now, while the terminal 1 on the PSTN 910 side and the IP terminal 4-1 on the IP network 920 side are talking, the terminal 1 makes a call to the IP terminal 4-2 (in this case, the caller of the terminal 1 is newly switched When the previous telephone number is dialed), the call connection unit 202 of MG2 receives the PB signal (push button signal) from the terminal 1 via the PSTN 910, and passes control to the connection destination switching unit 203 (FIG. 3). Step P1).
[0031]
The connection destination switching unit 203 to which control is passed extracts the destination telephone number (the value of the key pressed on the terminal 1) from the received PB signal, and the validity of the destination telephone number is transmitted to the MGC 3 via the communication unit 201. Is requested (step P2). In this case, the destination telephone number is IP terminal 4-2.
[0032]
Upon receiving the check request received via the communication unit 301, the connection state management unit 302 of the MGC 3 determines whether the destination telephone number obtained from the PB signal is correct (whether the destination telephone number exists). Determine. In this case, the connection state management unit 302 is connected to the IP network 920 via the communication unit 301 and manages an IP phone number (not shown) (IP phone number and IP address are stored in a database in the server). Etc.), the presence or absence of the destination telephone number is confirmed. In this case, if the server confirms the existence of the destination telephone number, the server transmits the result and the IP address of the destination to MGC 3.
[0033]
When the confirmation of the validity of the telephone number is completed, the connection state management unit 302 returns the result of confirmation and the IP address of the other party to the MG2. Although the server managing the IP telephone number is provided on the IP network 920, the MGC 3 may directly manage it as a database, or the server may be accessed using another communication network. Also good.
[0034]
When the determination is correct from the result received via the communication unit 201 (when the other party telephone number exists), the connection switching unit 203 of the MG2 switches the call connection unit 202 to the IP terminal 4-2. Instruct. Receiving the switching instruction, the call connection unit 202 switches to the IP terminal 4-2 by setting a call to the IP terminal 4-2 via the IP network 920 (step P3). In this case, the packet transmitted as the call setting includes the destination IP address, telephone number (IP terminal 4-2 telephone number), transmission source IP address (MG2 IP address), telephone number (terminal 1). Phone number) is set.
[0035]
Further, the call connection unit 202 determines whether or not the IP terminal 4-2 has made a response based on whether or not the response has been made (step P4).
Eventually, when the IP terminal 4-2 responds, the call connection unit 202 of the MG2 returns a response message indicating that the switching to the IP terminal 4-2 has been normally performed to the connection destination switching unit 203 via the communication unit 201. The connection destination switching unit 203 notifies via the communication unit 201 that the connection destination of the terminal 1 has been switched from the IP terminal 4-1 to the IP terminal 4-2 via the communication unit 301. The connection state management unit 302 of the MGC 3 that has received the notification sets “on hold” in the connection state column of the connection destination 1 of the connection destination state information 303 that has been on the call until now, and identifies the terminal of the switched connection destination 2 The terminal identification number (IP address and telephone number) of the IP terminal 4-2 is set in the number column, and “busy” is set in the connection status column. That is, a communication path is set between the terminal 1 and the IP terminal 4-2, and voice data flows through the call connection unit 202 of MG2 (step P5).
[0036]
If it is determined in step P2 that the telephone number of the other party input from the terminal 1 is incorrect, the connection destination is not switched and the line that is currently being used is used as it is. Also, if the result of the response message from MG2 in step P4 is abnormal, the connection destination switching process is not performed in the same manner, and the line currently being used for communication is used as it is.
[0037]
As described above, the terminal 1 on the PSTN 910 side can be connected to two or more IP terminals 4 on the IP network 920 side by following the procedure of FIG. In the case where there are three or more IP terminals 4 on the IP network 920 side, the connection destination status information 303 increases in order of connection destination 2, connection destination 3, connection destination 4,. Thus, the MGC 3 can manage the connection state. In addition, since the PSTN 910 side can be used for one call for one terminal, it is not possible to make a three-party simultaneous call, a four-party simultaneous call, etc., and a function to switch the other party with a two-party call is provided. To do.
[0038]
Next, connection in the case where the other party is two parties (an image in which the terminal 1 is calling from the PSTN side to the IP terminal 4-1 and the IP terminal 4-2 in the case of FIG. 1) The previous switching will be described using the flowchart shown in FIG.
[0039]
When the terminal 1 is in a connected state with two IP terminals 4 according to the procedure of FIG. 3 and is talking to one terminal 4 (for example, 4-2) (the other terminal 4-1 is on hold). In addition, when receiving the PB signal from the terminal 1 via the call connection unit 202, the connection destination switching unit 203 of the MG 2 extracts a specific symbol (for example, a special symbol such as # or *) from the received PB signal and connects it. It is determined as a destination switching notification. That is, when the connection destination switching unit 203 of the MG2 receives the PB signal carrying the special character indicating the connection destination switching notification via the PSTN 910 and the communication unit 301 (step P11 in FIG. 4), the MGC3 is transmitted via the communication unit 201. Request connection destination information to switch to. The connection state management unit 302 of the MGC 3 received through the communication unit 301 that has received the request searches the connection destination state information 303 to thereby display connection destination information (terminal identification) indicating switching to the pending IP terminal 4-1. (Including the number) is notified to MG2 (step P12).
[0040]
Upon receiving the connection destination information via the communication unit 201, the connection destination switching unit 203 instructs the call connection unit 202 to switch to the IP terminal 4-1. Upon receiving the switching instruction, the call connection unit 202 switches to the IP terminal 4-1 by setting a call to the IP terminal 4-1, and when the IP terminal 4-1 as the counterpart responds, It is determined that the switching has been performed normally, and a response message as a result is returned to the connection destination switching unit 203. The connection destination switching unit 203 notifies that the connection destination of the terminal 1 is switched from the IP terminal 4-2 to the IP terminal 4-1 via the communication unit 201. If the IP terminal 4-1 as the counterpart does not respond, it is determined as abnormal, and the result is posted in a response message and notified to the connection destination switching unit 203.
The connection destination switching unit 203 determines whether or not the connection destination can be switched normally by using a response message from the call connection unit 202 (step P13). This means that the previous IP terminal 4 has been switched from the IP terminal 4-2 currently on the call to the previously connected terminal 4-1 (at this time, the IP terminal with which the previous call was made) 4-2 is in a pending state), and notifies the connection information that the connection destination has been switched via the communication unit 201. Then, the connection state management unit 302 changes the connection state of the connection destination 1 (corresponding to the IP terminal 4-1 in this case) of the connection destination state information 303 based on the connection information received via the communication unit 301 to “call”. The connection state of the connection destination 2 (corresponding to the IP terminal 4-2 in this case) is set to “pending” (step P14).
[0041]
In step P13, if the result is abnormal when the call connection unit 202 responds to the connection destination switching unit 203, the connection destination is not switched, and the line currently being used is used as it is.
[0042]
In step P12, when there are two or more connection destinations (two or more connection destinations are registered in the connection destination state information 303), the connection state management unit 302 rotates (for example, the right side during a call) The connection destination N is selected by returning to the connection destination 1 if it is the rightmost side during a call.
[0043]
In the above-described step P11, if the PB signal received during the call has a specific symbol indicating switching, it is determined that the connection destination switching notification has been made, but the terminal 1 is on-hook during the call between the terminal 1 and the IP terminal 4-2. When a signal (a signal generated by an operation such as placing a handset or pressing a button to hang up the phone once) is received, it may be determined as a connection destination switching notification. That is, when the connection destination switching unit 203 of MG2 receives an on-hook signal from the terminal 1 via the PSTN 910 and the call connection unit 202, the connection destination information is determined as a connection destination switching notification and switched to the MGC 3 via the communication unit 201. Request. Since the subsequent operation is the same as the above description, the description is omitted.
[0044]
Next, a second embodiment of the present invention will be described with reference to the drawings.
[0045]
Referring to FIG. 5, a configuration example of the system according to the second embodiment is shown. The system includes a PSTN 910 that is a public subscriber telephone network, IP networks 920 and 930 that are IP networks, and a plurality of systems. Between the IP terminal 4 and the terminal 1, the terminal 1 that is a telephone terminal compatible with the public subscriber telephone network, the IP terminal 4 that is a plurality of Internet terminals (in the example, the IP terminals 4-1 and 4-2). It is composed of a plurality of MG2s that are media gateways that perform protocol conversion of data and the like, and an MGC3 that controls the plurality of MG2. Note that terminal 1, MG2 and MGC3 are connected to PSTN 910, and MG2 and IP terminal 4 are connected to IP network 920.
[0046]
The configurations in MGC3 and MG2 are the same as those in the first embodiment, but the network configuration connecting PSTN 910 and a plurality of IP networks is devised. In other words, referring to FIG. 5, a single PSTN 910 is a diagram focusing on connection to a plurality of IP networks (IP network 920 and IP network 930 in the figure). The IP network 920 and the IP network 930 are completely different networks, and in order to implement the present invention with the PSTN 910, one or more MG2s exist as contact points for different IP networks, and these MG2s are designated as MGC3. Is realized through centralized management.
[0047]
An initial connection from the PSTN 910 side is made to one of the MGs 2 in the figure, and the terminal 1 accommodated in the PSTN 910 side is in the state where the terminal 1 and the IP terminal 4 are in a call (connected). The connection destination state information is managed by the MGC 3 when the call is transmitted to any of the IP networks, and the present invention can be realized.
[0048]
Next, the operation of the second embodiment will be described with reference to FIG.
[0049]
When the terminal 1 on the PSTN 910 side is in a state of talking with the terminal 4-1 of the IP network 920 accommodated in the IP network 920, the IP terminal 4-2 accommodated in the IP network 930, which is another network, A case where connection switching is performed will be described as an example.
[0050]
When the MG 2 receives the PB signal from the terminal 1 (which includes the telephone number of the IP terminal 4-2), the MG 2 notifies that it is connected to the IP terminal 4-2 (as in the first embodiment). If the response of the notification is normal, the connection destination is switched to the IP terminal 4-2, and the MGC 3 "Pending" in the connection status column on the IP terminal 4-1 side, which is the connection destination 1 of the connection destination status information 303, the IP terminal 4-2 in the terminal identification number column of the connection destination 2, and the connection destination 2 In the connection status column, set “busy”.
[0051]
Similarly, when switching the connection destination terminal, the MG 2 receives a connection destination switching notification (either an on-hook signal or a PB signal with special characters such as “#” and “*”) from the terminal 1 on the PSTN side. As in the first embodiment, a notification to the effect that the connection to the IP terminal 4-2 is made (request for checking the validity of the destination telephone number of the IP terminal 4-2) is sent to the MGC 3, and the notification is made. Is normal, the connection destination is switched to the IP terminal 4-1, and “Pending” is displayed in the connection status column on the IP terminal 4-2 side that is the connection destination 2 of the connection destination status information 303 in the MGC 3. Is set in the connection status column on the IP terminal 4-1 side that is the connection destination 1. That is, the IP terminal 4 that was in a call enters a hold state (if it is connected to three or more devices, all terminals other than the terminal that is about to make a call will be in a hold state). Become.
[0052]
As described above, since the MG 2 switches the IP terminal 4 based on the PB signal, the connection between the PSTN side and the IP network side is logically performed, and the terminal 1 on the PSTN 910 side and the IP network 920, One-to-multiple calls with the IP terminal 4 on the 930 side can be made possible. In other words, if the telephone number of the destination IP terminal 4 is on the PB signal, the MG 2 switches to the new IP terminal 4 by making a call connection with a packet, so a specific physical line is newly set. If a special character indicating switching is on the PB signal, the MG 2 switches to the original IP terminal 4 by making a call connection with a packet. Calls can be made without providing a new line.
[0053]
Also, whenever the MG 2 receives a PB signal with a telephone number during a call, the MGC 3 obtains the connection destination information including the terminal identification number (IP address and telephone number) of the connection destination IP terminal 4 and the connection state thereof, PSTN 910. Since management is performed for each terminal 1 on the side, a plurality of calls can be made, and a user of the terminal 1 can connect to an arbitrary IP terminal 4 to make a call.
[0054]
【The invention's effect】
As described above, according to the present invention, the media gateway switches the IP terminal that is in a call to another IP terminal based on the PB signal carrying the telephone number of the IP terminal from the telephone terminal on the PSTN side. There is an effect that one PSTN side terminal can be connected to a plurality of IP network side IP terminals without newly providing a specific physical line.
[0055]
The present invention also provides that the media gateway control device receives the terminal identification number (IP address and telephone number) of the connection destination IP terminal and its connection state every time the media gateway receives a PB signal with a telephone number during a call. Since the connection destination information including is managed for each telephone terminal on the PSTN side, there is an effect that the user of the telephone terminal can connect to any IP terminal.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a system configuration of a first embodiment.
2 is a configuration diagram showing a configuration of connection destination state information of MGC in FIG. 1; FIG.
FIG. 3 is a flowchart showing an operation when the MG of FIG. 1 receives a PB signal carrying a telephone number from a PSTN terminal.
FIG. 4 is a flowchart showing an operation when the MG of FIG. 1 receives a connection destination switching notification from a PSTN side terminal;
FIG. 5 is a block diagram illustrating a system configuration according to a second embodiment;
[Explanation of symbols]
1 terminal
2 MG
3 MGC
4 IP terminal
201, 301 Communication unit
202 Call connection
203 Connection destination switching unit
302 Connection state management unit
303 Connection destination status information
910 PSTN
920,930 IP network

Claims (8)

An Internet telephone system for performing voice communication via a gateway between a plurality of telephone terminals connected to a public subscriber telephone network and a plurality of IP terminals connected to an IP network,
The gateway for establishing a call connection between the telephone terminal and the plurality of IP terminals;
A control device for the gateway that controls the gateway, and
The gateway is
Upon receiving the push-button signal from a telephone terminal in the call during a call with the IP terminal and the telephone terminal, extracting means for extracting the telephone number of IP terminal of the new connection destination from said push-button signal,
Requests the confirmation of the validity of a new connection versus the telephone number of IP terminal of the new connection destination and the extracted to the control device, the IP address of the confirmation result and the new connection destination of validity of the telephone number When receiving from the control device, a packet in which the IP address of the new connection destination is set is transmitted to perform a call connection to the new connection destination, and the IP address of the new connection destination extracted from the IP terminal in the call A switching means for switching to a terminal to make a call state;
Have
The controller is
The validity of the connection corresponding to the telephone number inquired from the gateway is confirmed, and the validity confirmation result and the IP address of the connection destination corresponding to the telephone number are transmitted to the gateway. An internet telephone system comprising management means for managing connection information between a plurality of IP terminals that have made call connections from the telephone terminals based on notifications, for each of the telephone terminals. The connection information includes a terminal identification number including an IP address and a corresponding telephone number of each of the plurality of IP terminals that have made a call connection from the telephone terminal, and whether the telephone terminal is busy or on hold. Connection status to indicate,
The management means updates the connection status of each of the plurality of IP terminals that have made a call connection from the telephone terminal based on a notification from the gateway, whether the call is on hold or on hold. Item 1. Internet telephone system. When the switching means receives a push button signal or an on-hook signal carrying a special character indicating switching from the telephone terminal that is in a call during a call between the telephone terminal and the IP terminal , the switching means switches the connection destination information to be switched. And switching the IP terminal of the connection destination with the telephone terminal based on the connection destination information indicating the switching to the pending IP terminal retrieved from the connection information managed by the management means. Item 3. Internet telephone system. The switching means transmits a call setting packet set with a new IP address of the connection destination received from the control device, and receives a response from the IP terminal of the new connection destination, changes the connection status to the control device. The Internet telephone system according to claim 2 or 3, characterized in that: An internet telephone method for performing voice communication via a gateway between a plurality of telephone terminals connected to a public subscriber telephone network and a plurality of IP terminals connected to an IP network,
The gateway for establishing a call connection between the telephone terminal and the plurality of IP terminals;
A terminal identification number including the IP address of the connection destination and the telephone number of the IP terminal of the connection destination;
A terminal identification number including an IP address of the IP terminal of the connection destination and a telephone number of the IP terminal of the connection destination;
A gateway control device for managing connection information including connection status of the IP terminal indicating whether the call is on hold or on hold for each of the telephone terminals; and
The gateway is
When a push button signal is received from the telephone terminal in the middle of a call between the telephone terminal and the IP terminal, the telephone number of the IP terminal of the new connection destination is extracted from the push button signal,
Requests the confirmation of the validity of a new connection versus the telephone number of IP terminal of the new connection destination and the extracted to the control device, send the IP address of the confirmation and the new connection destination of validity of the telephone number Then, a call connection to a new connection destination is performed , and the IP terminal in the call is switched to the extracted new connection destination IP terminal to be in a call state.
The control device confirms the validity of the connection corresponding to the telephone number inquired from the gateway, and transmits the validity confirmation result and the IP address of the connection destination corresponding to the telephone number to the gateway. An internet telephone method for managing connection information for each of the plurality of IP terminals that have made a call connection from the telephone terminal based on the notification from the gateway . The connection information includes a terminal identification number including an IP address and a corresponding telephone number of each of the plurality of IP terminals that have made a call connection from the telephone terminal, and whether the telephone terminal is busy or on hold. Connection status to indicate,
  The management means updates the connection status of each of the plurality of IP terminals that have made a call connection from the telephone terminal based on a notification from the gateway, whether the call is on hold or on hold. Item 6. The Internet telephone method according to Item 5. When the switching means receives a push button signal or an on-hook signal carrying a special character indicating switching from the telephone terminal that is in a call during a call between the telephone terminal and the IP terminal, the switching means switches the connection destination information to be switched. And switching the IP terminal of the connection destination with the telephone terminal based on the connection destination information indicating the switching to the pending IP terminal retrieved from the connection information managed by the management means. Item 7. The Internet telephone method according to Item 6 . The switching means transmits a call setting packet set with a new IP address of the connection destination received from the control device, and receives a response from the IP terminal of the new connection destination, changes the connection status to the control device. The Internet telephone system according to claim 6 or 7, characterized in that:

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