JP2003032368A - CALLING STATE TRANSFER SWITCH-BACK METHOD IN VoIP PHONE SYSTEM, THE VoIP PHONE SYSTEM, AND PHONE TERMINAL AND SWITCH MANAGEMENT DEVICE FOR THE VoIP PHONE - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a function of a calling state transfer switchback function, even in a VoIP phone system which is in compliance with the ITU-T recommendation H. 323. SOLUTION: When a switchback operation is detected by a transfer source, before a transfer destination responds to a call after starting a calling state transfer procedure is started, a transfer source transmits a facility message of a switchback request to an IP network. The facility message for indicating a failure of transfer to the transfer destination by the calling state transfer procedure is notified to the transfer source. Furthermore, a speech state by end of transfer is notified by the facility message, to bring a call state to the transfer source and the transfer destination, depending on the switchback operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to VoIP (VoIP).
ice over Internet Protocol
l) Telephone system, telephone terminal and exchange management device for this VoIP telephone system.

[0002]

2. Description of the Related Art There has been provided a VoIP telephone system for performing telephone communication using VoIP which is a technique for transmitting a voice signal using an IP (Internet Protocol) network such as the Internet or an intranet. This VoIP telephone system is configured using, for example, ITU-T Recommendation H.323 which is a standard for a general LAN (local area network).

FIG. 7 is a block diagram showing an overview of the entire VoIP telephone system. That is, the VoIP telephone system includes a gatekeeper 1 and a plurality of telephone terminals 2.
, 2n, LAN 3, and VoIP gateway 4.

Each of the plurality of telephone terminals 21 to 2n is
Handset 21 with computer functions
H-2nH. The plurality of telephone terminals 21 to 2n are LANs forming an IP network.
Gatekeeper 1 connected to LAN 3 through this LAN 3
It is connected to the.

The VoIP gateway 4 is connected to the telephone network 5 by a plurality of telephone lines 6 and is also connected to the LAN 3. The gateway 4 plays a role of a relay management device having a function of connecting the telephone network 5 and the IP network, and performs mutual conversion between a continuous voice signal and an IP voice packet and a gatekeeper 1 of the IP voice packet. And the mutual conversion between the telephone number and the IP address.

[0006] In this case, LAN3 is ITU-T Recommendation H.264. The IP network is configured according to the standard of H.323.

The gatekeeper 1 is based on ITU-T Recommendation H.264.
It is responsible for a central management function in the system configuration of 323, and is configured by, for example, a personal computer. Each of the plurality of telephone terminals 21 to 2n has a LAN 3
Will be registered in Gatekeeper 1 when connected to.

The gatekeeper 1 manages the exchange of the gateway 4 and a plurality of telephone terminals 21 to 2n in the system, allocates the bandwidth, associates the telephone number with the IP address, and registers a plurality of them. It serves as an exchange management device having a function of managing telephone communication using a plurality of telephone lines 6 by a telephone terminal.

[0009]

SUMMARY OF THE INVENTION A V having a configuration as shown in FIG.
The oIP telephone system is considered to have the same function as that of a conventional button telephone system, and a call on hold is transferred to a transfer destination while the other party recognizes that the other party is calling. The call transfer performed in accordance with ITU-T Recommendation H.264. It is also realized in a VoIP telephone system using H.323.

[0010] However, the function of call back transfer back to switch back the call transfer during call back to the transfer source is described in ITU-T Recommendation H.264. It was very inconvenient because it was not defined in the VoIP telephone system using H.323.

In view of this point, the present invention is based on VoIP.
In the telephone system, ITU-T Recommendation H.264. Also in the VoIP telephone system using H.323, the function of performing call back during call back is provided by ITU-T Recommendation H.264. It is intended to realize the standard without changing the H.323 standard and without making any special agreement.

[0012]

In order to solve the above-mentioned problems, in the method for switching back and forth during a call in the VoIP telephone system according to the present invention, after the transfer procedure during a call is activated,
When it is detected that the transfer source has performed a failback operation before the transfer destination responds, the transfer source sends a message of a failback request to the IP network. Based on the message, the message indicating that the transfer to the transfer destination by the call transfer procedure has failed is notified to the transfer source, and the transfer destination is notified of the call state due to the transfer end by the message. Then, the transfer source and the transfer destination are put into a call state according to the switchback operation.

In this case, the failback request included in the message of the failback request from the transfer source may be included as manufacturer-specific information.

[0014]

According to the present invention having the above-described structure, after the transfer procedure during a call is activated, before the transfer destination responds, when the transfer source performs a failback operation, the transfer procedure during a call fails. As a result, only the call between the transfer source and the transfer destination can be left, and the call back transfer failback can be realized.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a VoIP telephone system according to the present invention and a call forwarding transfer failback method in this system will be described below with reference to the drawings. The basic configuration of the VoIP telephone system in this embodiment is exactly the same as the configuration of FIG. 10 described above.

However, in this embodiment, LA
Each of the plurality of telephone terminals connected to N3 is the telephone terminal 100 capable of performing the call forwarding transfer failback operation, and when the gatekeeper requests the call forwarding transfer failback from the telephone terminal. , A gatekeeper 2 having a function of interpreting the request message and executing a sequence for making a call back transfer failback state as described later.
It is different from the configuration of FIG. 7 in that it is 00.

[Example of Hardware Configuration of Telephone Terminal 100]
FIG. 2 shows an example of a hardware configuration of the multi-line compatible telephone terminal 100 in the system of this embodiment. The telephone terminal 100 of this embodiment includes a terminal body 101,
And a handset 102. Handset 102
Although not shown, includes a microphone that constitutes a transmitter, a transmitter amplifier, a speaker that constitutes a receiver, and a receiver amplifier.

The terminal main body 101 is composed of a computer, and has a system bus 1 for the CPU 110.
A ROM 112, a RAM 113, a display controller 114, an operation input interface (an interface is described as an I / F in the figure. The same applies hereinafter) 116, a LAN interface 118, a packet disassembly / generation unit 119, and a voice. The data input / output interface 120 is connected.

A display 115 is connected to the display controller 114, and a display screen of the display 115 displays according to the control of the CPU 110.

Further, the operation input interface 116 includes an operation input section 117 including a ten-key pad, a cursor key, a call transfer key, a call cutback key and other operation keys.
Are connected. The CPU 110 recognizes which input key the user has operated through the operation input unit 117 via the operation input interface 116, and based on the recognition result, performs the processing corresponding to the key input operation in the ROM 1
12 programs are executed.

The ROM 112 is for executing a processing sequence for registering the telephone terminal 100 in the gatekeeper 200, and a processing sequence for transfer during call including a processing sequence for failback. Programs etc. are stored.

The RAM 113 is mainly used as a work area when the program of the ROM 112 is executed by the CPU 110.

The LAN interface 118 is a LAN
Take in the packetized data sent through 3,
It also has a function for sending packetized data to the LAN 3.

The packet disassembly / generation unit 119 has a function of disassembling the packetized data captured by the LAN interface 118 to obtain control data and voice data,
It has a function of packetizing control data and voice data to be transmitted and generating packetized data to be transmitted. The packet decomposing / generating unit 119 includes a buffer memory for decomposing or generating packetized data.

The packet disassembling / generating unit 119 has a packet disassembling processing function and a generating processing function which are executed by the CPU 110.
It can also be realized as software by the ROM 112 and the ROM 112.

Audio data input / output interface 120
Has a function of converting voice data obtained by packet decomposition into an analog voice signal and supplying the analog voice signal to the handset 102, and a function of converting an analog voice signal input from the handset 102 into a digital signal and capturing the digital signal.

[Hardware Configuration Example of Gatekeeper 200] Next, a hardware configuration example of the gatekeeper 200 in the system of this embodiment is shown in FIG. The gatekeeper 200 of this embodiment is composed of a personal computer, for example, and has a CPU 21.
0 to the ROM 212 via the system bus 211
, RAM 213, LAN interface 214
The packet processing unit 215 and the network management memory 216 are connected to each other.

The ROM 212 stores a program for executing a processing sequence when there is a call transfer request or a switchback request from the telephone terminal 100, a processing program for converting telephone number information and an IP address, and the like, the gatekeeper 200. The processing program executed by is stored.

The RAM 213 is mainly used as a work area when the program of the ROM 212 is executed by the CPU 210.

Further, the LAN interface 214 is
It has a function of taking in packetized data sent through the LAN 3 and sending the packetized data to the LAN 3.

When the packet fetched by the LAN interface 214 is a control data packet, the packet processing unit 215 decomposes the received packet in order to decode the control data, and also controls the transmission. It has a function of generating packetized data.

When the packet fetched by the LAN interface 214 is a voice data packet, the gatekeeper 200 sends the packet from the gateway 4 to the telephone terminal, and the packet from the telephone terminal to the gateway 4 or another. Transfer the voice packet to the telephone terminal.

The packet processing unit 215 has a buffer memory for decomposing / generating the packetized data and temporarily storing the packetized data for transfer processing.

The network management memory 216 stores the registration information of the gateway 4 and a plurality of telephone terminals existing in the network, their IP addresses, and the I of the telephone terminals.
Information such as correspondence between P address and telephone number is stored. The CPU 210 determines the destination IP address of the packet and determines the destination IP address using the information.

Next, the sequence of call transfer and call back transfer failback in this embodiment will be described. FIG. 4 is a flowchart of the processing executed by the telephone terminal 100 of the transfer source at the time of call transfer and call back transfer failback, and FIG. 5 is the gatekeeper 200 at the time of call transfer and call transfer transfer failback. It is a flowchart of the process performed by. FIG. 6 is a sequence diagram when a call is transferred to the transfer destination by transfer during call.
FIG. 7 is a sequence diagram when the call is not transferred to the transfer destination and is switched back to the transfer source.

[Sequence of Transfer During Call] First, a case in which transfer of a call to a transfer destination succeeds due to transfer during a call will be described with reference to the flowcharts of FIGS. 6 and 4.

As shown in FIG. 6, when a transfer operation is performed at the transfer source telephone terminal while the call is on hold (step S in FIG. 4).
1), the telephone terminal 100 of the transfer source concerned sends a facility message FAC (ctIniti
ate. inv) to the gatekeeper 200.
Here, the facility message FAC is a message for performing various services without changing the call state.

When the gatekeeper 200 receives the facility message FAC of the transfer start instruction during the call (step S11), the facility message FAC (ctComplete.in) indicating that the transfer is in progress is transmitted to the transfer destination.
v [Alerting]) is sent (step S12).
As a result, the transfer destination telephone terminal causes the user to hear a ringing tone indicating that the transfer destination is being called.

The gatekeeper 200 also sends a call request for transfer to the transfer destination by the facility message FAC.
(CtComplete.inv [Answere
(d))) (step S13). As a result, the caller's ringer rings at the transfer destination telephone terminal.

Next, the gatekeeper 200 releases a message REL COM to release the connection with the transfer source telephone terminal.
P is sent to the transfer source telephone terminal (step S14).

When the user at the transfer destination responds to the call request by the transfer, the transfer destination telephone terminal sends a connection message CONNECT to the gatekeeper 200. Therefore, the gatekeeper 200 determines whether or not the transfer destination has responded, depending on whether or not the message CONNECT of the connection has been received (step S15).

Upon determining that the transfer destination has responded, the gatekeeper 200 informs the transfer source of a connection release message REL COMP (ctInitiat) based on the completion of the transfer to the transfer destination by the transfer procedure during call.
e. rr (where “rr” is “return re
"sult", which means reporting the transfer result. )) Is sent (step S16).

When the transfer source telephone terminal 100 receives the connection release message REL COMP sent by the gatekeeper 200 in step S14 (step S3), the transfer is completed to the transfer destination by the call transfer procedure. Release message based on REL CO
It waits for MP (ctInitiate.rr) (step S4). Then, the connection release message REL COMP
Upon confirming the reception of (ctInitiate.rr) (step S4), the transfer source releases the call (step S5).

Next, the gatekeeper 200 sends a facility message FAC (ctActive.in) indicating that the transferred call can be communicated to the transfer destination.
v) is sent (step S17). As a result, the call transfer is performed between the transfer destination and the transfer destination.

[Sequence for Callback Transfer Return] Next,
A case in which the switchback operation is performed at the transfer source before the transfer destination responds while the call transfer procedure is being executed will be described with reference to the sequence diagram of FIG. 1 and the flowcharts of FIGS. 4 and 5.

In this call back transfer failback sequence, the processing from when the call source transfer start instruction from the transfer source telephone terminal until the gatekeeper 200 sends the connection release message REL COMP to the transfer source is: This is exactly the same as the case where the transfer during call described above succeeds. That is, up to step S3 in the processing flowchart of the telephone terminal 100 of FIG. 4, and step S1 in the processing flowchart of the gatekeeper 200 of FIG.
Up to 4 is the same as above.

In this switchback sequence, FIG.
As shown in, the failback operation is performed in the transfer source telephone terminal 100 before the response operation is performed in the transfer destination.
Then, in the telephone terminal 100, the connection release message REL based on the completion of the transfer to the transfer destination in step S4.
The switchback operation is detected in step S6 without detecting the reception of COMP (ctInitiate.rr).

When the telephone terminal of the transfer source detects this switchback operation, the telephone terminal of the ITU-T recommendation H.264. As a NSD (Not Standard; manufacturer-specific information) defined by H.323, a facility message FAC including a switchback request is sent to the gatekeeper 200 (step S7).

When the gatekeeper 200 receives the facility message FAC including the failback request before receiving the response from the transfer destination (step S18).
A facility message FAC (ctInitiate.re) indicating that the transfer to the transfer destination by the transfer procedure during a call has failed to the transfer source that has made the switchback request.
(Where "re" is "return error"
Which means that the transfer has failed. ))
Is sent (step S16).

Further, the gatekeeper 200 sends a facility message FAC (ctActive.i) to the transfer destination, which means that the transferred call can be talked.
nv) is sent (step S17).

When the transfer source telephone terminal 100 receives the transfer failure facility message FAC (ctInitiate.re) from the gatekeeper 200 (step S8), it keeps the call being transferred and sets it as the transfer destination. A call state is entered (step S9).

As described above, in response to the switchback operation at the transfer source, the state in which the transfer source and the transfer destination are in a call is restored. That is, the call back transfer is switched back. In this case, according to this embodiment, in the gatekeeper,
In response to the switchback request from the telephone terminal, the switchback is realized by setting the transfer during call failure state.
ITU-T Recommendation H.264. A remarkable effect that transfer back during call can be performed without making any special change to the H.323 standard is achieved.

Further, in the above-described embodiment, the telephone terminal is configured to generate the switchback request using NSD (manufacturer-specific information). It is possible to implement call back transfer failback while complying with the H.323 standard.

A plurality of telephone terminals as described above and a gatekeeper for managing them are set as one group, and a plurality of groups are connected to the IP network to form a VoIP telephone system. It is also possible to perform call forwarding and call back between the groups. In that case, the operations of the transfer source, the transfer destination, and the transfer destination can be performed by the gatekeeper managing the respective groups.

[0055]

As described above, according to the present invention, H.264 of ITU-T recommendation is recommended. It is possible to realize a VoIP telephone system that can easily realize call back transfer failback not defined in the H.323 standard. Further, according to the present invention, the H.264 standard recommended by ITU-T is used. There is also a remarkable effect that it can be realized while complying with the H.323 standard.

[Brief description of drawings]

FIG. 1 is a sequence diagram for illustrating a sequence of call back transfer failback in a VoIP telephone system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a hardware configuration example of a telephone terminal for the VoIP telephone system according to the embodiment of the present invention.

FIG. 3 is a block diagram showing a hardware configuration example of a gatekeeper for the VoIP telephone system according to the embodiment of the present invention.

FIG. 4 is a flowchart for explaining a processing operation of call forwarding during call in the telephone terminal for the VoIP telephone system according to the embodiment of the present invention.

FIG. 5 is a flowchart for explaining a processing operation of call forwarding during call in the gatekeeper for the VoIP telephone system according to the embodiment of the present invention.

FIG. 6 is a sequence diagram for explaining a sequence of call forwarding in the VoIP telephone system according to the embodiment of the present invention.

FIG. 7 is a block diagram showing an outline of a configuration of a VoIP telephone system.

[Explanation of symbols]

3 LANs that make up the IP network Telephone terminal for 100 VoIP telephone system Gatekeeper for 200 VoIP telephone system

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koji Yamamiya             6-10-13 Nakanobu, Shinagawa-ku, Tokyo Stock market             Inside the Daiko Denki Seisakusho (72) Inventor Hiroyuki Nakamura             3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Tohnichi             Inside Telegraph and Telephone Corporation (72) Inventor Takafumi Hayashi             3-15 Babacho, Chuo-ku, Osaka-shi, Osaka             Inside Telegraph and Telephone Corporation F-term (reference) 5K024 AA45 CC01 CC10 DD06                 5K030 GA11 HB01 HC02 HC14 HD03                       HD06 JT01 LB01                 5K051 AA08 BB01 BB02 CC01 DD01                       EE01 GG07 HH27 KK05                 5K101 KK02 LL01 LL03

Claims (7)

[Claims] 1. When a transfer-back operation is detected at the transfer-source after the transfer-during-calling procedure is activated and before the transfer-destination responds, the transfer-source requests the IP network to switch back. And sending a message indicating that the transfer to the transfer destination by the calling transfer procedure has failed to the transfer source based on the message of the failback request, and the transfer destination Is notified of a call state due to the end of transfer by a message, and sets the transfer source and the transfer destination to a call state according to the switchback operation. Method. 2. A call back transfer reverting method in a VoIP telephone system according to claim 1, wherein the message of the reverting request from the transfer source includes a reverting request as manufacturer-specific information. . 3. A plurality of telephone terminals connected to a local area network forming an IP network, and a plurality of registered telephone terminals connected to the plurality of telephone terminals via the local area network. In the VoIP telephone system including a switching management device having a function of performing a switching management of the telephone communication regarding the above, the transfer source telephone terminal sends, to the exchange management device, an instruction to activate transfer during a call in response to a transfer operation. And means for transmitting a message of a failback request to the exchange management device in response to a failback operation, wherein the exchange management device receives a transfer destination when receiving an instruction to activate the transfer during call. To the transfer destination telephone terminal, and to the transfer source telephone terminal a connection release message. And a means of sending the switchback request message from the transfer source before the transfer destination responds, the transfer source telephone terminal transfers the call to the transfer destination by the call transfer procedure. Means for notifying the transfer source of a message indicating that the transfer has failed, and for notifying the transfer destination of the call status due to the end of transfer by a message. 4. The VoIP telephone system according to claim 3, wherein the switchback request message from the transfer source includes a switchback request as manufacturer-specific information. 5. A plurality of telephone terminals connected to a local area network forming an IP network, and a plurality of telephone terminals connected to and registered with the plurality of telephone terminals via the local area network. The telephone terminal for a VoIP telephone system, comprising: a switching management device having a function of switching and managing the telephone communication of, and a means for sending an instruction to activate transfer during a call to the switching management device in response to a transfer operation. A telephone terminal for a VoIP telephone system, comprising: means for transmitting a message including a switchback request as manufacturer-specific information to the exchange management device in response to a switchback operation. 6. A plurality of telephone terminals connected to a local area network forming an IP network, and a plurality of telephone terminals connected to and registered with the plurality of telephone terminals via the local area network. The exchange management device for a VoIP telephone system, comprising: a exchange management device having a function of exchanging and managing telephone communication for Notify the transfer destination telephone terminal that the call is in progress, and notify the transfer destination telephone terminal of the transfer call.
Means for sending a connection release message to the transfer source telephone terminal, and when the transfer request message is received from the transfer source before the transfer destination responds, the transfer source telephone terminal, Means for notifying the transfer source of a message indicating that the transfer to the transfer destination by the transfer procedure during a call has failed, and notifying the transfer destination by a message of the call status due to the transfer end. An exchange management device for a VoIP telephone system characterized by the following. 7. The exchange management device for a VoIP telephone system according to claim 6, wherein the message of the switchback request from the transfer source includes the switchback request as manufacturer-specific information.