JPH05252313A - Method for controlling transmission in isdn terminal equipment - Google Patents

Abstract

PURPOSE:To prevent the generation of mismatch between plural terminals and to properly execute transfer operation from an outgoing terminal to a transfer terminal by attaining incoming call transfer not by an ISDN function but by an independent terminal function. CONSTITUTION:The transmission control method for an ISDN terminal equipment using an ISDN as a transmission line is provided with a storage means for storing the terminal identification(ID) information of an incoming transferred destination and when an incoming call transfer mode is set up at the time of detecting an incoming call, the incoming terminal sends a release completion message REL-COMP in the informed state of the terminal ID information of the incoming transfer destination which is stored in the storage means to reject the incoming call. The outgoing terminal receives the message REL-COMP at the time of outgoing call, and when the terminal ID information is included in the message REL-COMP, calls the informed incoming transfer destination to transfer information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission control method for an ISDN terminal device using ISDN as a transmission line.

[0002]

2. Description of the Related Art One of the service functions of ISDN is a call transfer function. This is activated by a request from the called user, connects the call to the transfer destination specified by the called user,
The information transfer can be realized between the calling user and the transfer destination user.

When this incoming call transfer function is used, for example, when the called user is moving to another place, the incoming call can be received at the moving destination and the usability of the ISDN is improved.

[0004]

However, the use of such a call transfer function causes the following inconveniences.

For example, in the group 4 facsimile apparatus, the image information transfer operation is performed according to a predetermined transmission procedure. In this transmission procedure, various kinds of information are exchanged between the sending terminal and the receiving terminal in order to check the function and connectability. For example, in the session layer, the calling terminal (transmitting terminal) sends a session start command CSS to set a connection in the session layer, and the called terminal (receiving terminal) responds with a session start positive response RSSP, Confirming mutual functions.

At this time, for confirmation of the partner terminal, for example, the session start positive response RSSP includes the called terminal identifier. The calling terminal analyzes the content of this called terminal identifier and It is determined whether the destination terminal is the designated destination.

By the way, as described above, when the calling terminal is connected to the transfer destination terminal by the call transfer function and the call is established between them, the call reception included in the session start acknowledgment response RSSP is called. The terminal identification value of the transfer destination terminal at that time is set in the value of the terminal identifier.

On the other hand, the calling terminal compares the value of the called terminal identifier included in the received session start acknowledgment RSSP with the terminal identification information of the first called terminal. In this case, as a matter of course, since the two do not match, the calling terminal aborts the information transfer operation at that point.

In this way, when the call transfer function is applied, there is a disadvantage that the information transfer operation cannot be performed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control method for an ISDN terminal device which can appropriately utilize a call transfer function.

[0011]

The present invention provides a transmission control method for an ISDN terminal device using ISDN as a transmission path, comprising storage means for storing terminal identification information of a call transfer destination, wherein the called terminal detects an incoming call. At this time, when the call transfer mode is set, the release completion message is sent in the state in which the terminal transfer destination terminal identification information stored in the storage means is notified, and the incoming call is rejected, and the calling terminal calls Sometimes, when a release completion message is received and the release completion message contains the terminal identification information of the call transfer destination, the notified call transfer destination is called to transfer the information. is there.

When the calling terminal calls the call transfer destination to establish an information channel and the session user data of the procedure signal received from the partner terminal in the session procedure includes the closed group number. , The closed group number preset in the terminal is compared with the notified closed group number, and if they match, the subsequent information transfer operation is executed, and if they do not match, the information is The transfer operation should be terminated.

Further, the calling terminal displays the called terminal identifier included in the procedure signal received from the partner terminal in the session procedure by calling the call transfer destination and establishing the information channel, and transfers it to the user. It is advisable that the continuation of the operation is confirmed, the information transfer operation thereafter is executed when the continuation of the transfer operation is designated, and the information transfer operation is terminated when the discontinuity of the transfer operation is designated.

Further, when the calling terminal aborts the information transfer operation, it is preferable that the notified call transfer destination is stored in the communication history information.

IS using ISDN as a transmission line
In the transmission control method of a DN terminal device, when calling, ISD
When the call transfer is notified from N, the operation is performed by replacing the notified identification information of the transfer destination with the identification information of the call destination at the time of information transfer.

[0016]

Therefore, since the call transfer is realized not by the ISDN function but by the function unique to the terminal, the mismatch between the terminals can be prevented, and the information transfer operation from the calling terminal to the transfer destination terminal is properly performed. Be done. Further, when the call transfer is notified from the ISDN, the calling terminal, in order to replace the notified identification information of the call transfer destination with the identification information of the call destination at the time of information transfer, the calling terminal and the transfer destination terminal. It is possible to prevent inconsistency between them, and therefore, the information transfer operation between the calling terminal and the transfer destination terminal is appropriately performed.

[0017]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a group 4 facsimile apparatus according to an embodiment of the present invention. This group 4 facsimile apparatus is a meeting terminal apparatus that uses ISDN as a transmission path.

In FIG. 1, the control unit 1 mainly performs the control process of each unit of the group 4 facsimile machine and the group 4 facsimile transmission procedure process of the upper layer, and the system memory 2 is executed by the control unit 1. It stores a control processing program and various data necessary for executing the processing program, and constitutes a work area of the control unit 1. The parameter memory 3 stores, for example, terminal identification information of a call transfer destination. ,
Mode information for storing the setting of the call transfer mode, or for storing various information unique to this group 4 facsimile machine such as a closed group ID set for limiting the partner terminal to be connected Is.

The scanner 4 is for reading an original image at a predetermined resolution, the plotter 5 is for recording and outputting an image at a predetermined resolution, and the operation display unit 6 is a facsimile device. For operation,
It consists of various operation keys and various indicators.

The encoding / decoding unit 7 is for encoding and compressing the image signal and for decoding the encoded and compressed image information into the original image signal. The image storage device 8 is
This is for storing a large amount of image information in a coded and compressed state.

The ISDN interface circuit 9 connects the group 4 facsimile apparatus to the ISDN, and integrates the signal processing function of the layer 1 and the D channel (signal channel) signal and the two B channel (information channel) signals. Since the D channel transmission control unit 10 has a separation function, the D channel transmission control unit 10 performs ISD for call setup / call release procedure processing.
This is for executing signal processing on the N D channels, and the B channel transmission control units 11 and 12 are for realizing the group 4 facsimile transmission procedure function performed on the B channels.

These control unit 1, system memory 2,
Parameter memory 3, scanner 4, plotter 5, operation display unit 6, encoding / decoding unit 7, image storage device 8, D channel transmission control unit, and B channel transmission control units 11 and 1.
2 is connected to the system bus 13, and data is exchanged between these respective elements mainly through the system bus 13.

FIG. 2 shows an example of the transmission procedure of the group 4 facsimile machine.

First, the calling terminal sends a call setup message SETUP, which is destined to the intended called terminal, to the ISDN to request a call setup with the called terminal, whereby the ISDN is set up.
Sends a call setting acceptance message CALL_PROC for notifying the call setting status to the calling terminal and sends a call setting message SETUP to the designated called terminal to call.

When the destination terminal responds to the incoming call, it sends a response message CONN to the ISDN.
Sends a response confirmation message CONN_ACK to the destination terminal to confirm the response of the destination terminal, and at that time, an information channel (B channel) for data transmission is established between the source terminal and the destination terminal. , The calling terminal and the called terminal are B
Initiate the transmission procedure on the channel.

First, the calling terminal sends a command SABM to request the setting of the link layer, and the called terminal responds with a response UA. This sets the link layer.

Then, the calling terminal sends a signal SQ in order to set up the network layer end to end,
The destination terminal sends a signal SF to accept it,
Then, the calling terminal sends a signal CR for a calling request, and the called terminal responds with a signal CA to accept the call, whereby the network layer is set.

Next, the calling terminal sends a signal TCR to set the transport layer, and the called terminal sends a signal TCA to accept it, whereby the transport layer is set.

Then, the calling terminal sends a session start command CSS to set the session layer connection, and the called terminal responds with a session start acknowledgment response RSSP, whereby the session layer is started. ..

Next, the calling terminal sends a document function list command CDCL to negotiate the transmission function to be used, and the called terminal sends a document function list affirmative response RDCLP, whereby the reception capability is confirmed. Adjustments are made.

In this way, when the preparation for image information transmission is completed, the calling terminal starts the document with various information for managing the document information to be transmitted such as the document reference number for distinguishing the document to be transmitted. Following the command CDS, a plurality of document user information commands CDUI
To send the image information for one document, and when the transmission is completed, send the document end command CDE
Notify the end of the image information of the document.

The destination terminal is the document end command CD
When E is received, a document end affirmative response RDE indicating that the reception of the document (image information) is normally completed
Send P.

When the image information transmission for one document is completed in this way, the calling terminal sends the session end command CSE.
And the destination terminal sends a session end affirmative response RS
Send EP to release the session layer connection.

Then, the calling terminal sends a signal CQ of the network layer, whereas the called terminal sends a signal CF, whereby the network layer is released, and the calling terminal sends a command of the link layer. DIS
C is sent, and the destination terminal sends a response UA, which releases the link layer.

In this way, when the link (call) on the B channel is released, the calling terminal sends the disconnection message DI.
SC is sent to ISDN to request the release of the information channel, and ISDN sends a release message REL to the calling terminal to notify the restoration of the information channel. On the other hand, ISDN
Sends a disconnect message DISC to the destination terminal to request the release of the information channel, and the destination terminal releases the release message RE.
L is sent to ISDN to notify the restoration of the information channel.

As a result, the calling terminal IS sends the release completion message REL_COMP notifying the completion of channel disconnection.
In response to the DN, the information channel between the calling terminal and the ISDN is released. Along with that, ISDN
Sends a release complete message REL_COMP to the destination terminal, which releases the information channel between the ISDN and the destination terminal. As a result, the information channel set up between the calling terminal and the called terminal is completely released.

In this way, the information channel is set between the calling terminal and the called terminal, data transmission is performed, and when the data transmission is completed, the information channel is released.

Further, each message for ISDN call setup is, as shown in FIG. 3A, a protocol specification (format, format,
Protocol identifier to identify the sequence, etc.)
Call number to identify which call the message pertains to, message type to identify the content of each message, mandatory information elements that must be added to each message, and each message It consists of additional information elements added as required. It should be noted that 0, 1, or a plurality of essential information elements are set according to the message type, and 0, 1, or a plurality of additional information elements are arranged according to the situation.

The call setup message SETUP is, as shown in FIG. 6B, "transmission capability" as an essential information element.
And the additional information element is, for example, "calling number",
It has information elements such as "Called number", "Called sub-address", "Lower layer compatibility", "Higher layer compatibility", and "User-user".

Further, the release completion message REL_COM
P has, for example, "reason display" as an essential information element, and has information elements such as "display" and "user / user" as additional information elements.

An outline of these information elements will be described.

The "transfer capability" information element is an information transfer that indicates whether the content of the information to be transmitted is voice, unrestricted digital information, restricted digital information, 3.1 KHz audio, 7 KHz audio, or video. Capability, transfer mode indicating whether the switching function used is circuit switching or packet switching, information transfer speed indicating information transfer speed, information indicating information transfer mode, and information indicating user information protocol, etc. Consists of.

The "calling number" information element is the ISDN of the calling terminal.
Represents the number and the "Called Number" information element is the IS of the called terminal.
Indicates the DN number. The "Destination Sub Address" information element is
This is for identifying the intended terminal of up to eight terminals connected to the same home wiring (passive bus) on the destination side.

The "Lower layer compatibility" information element is for use in the communication possibility check with the partner terminal,
The basic contents are the same as the “Transmission capability” information element. Furthermore, this "lower layer compatibility" information element contains more detailed content.

The "higher layer compatibility" information element is used for consistency check with the partner terminal, and is, for example, telephone, group 2 / group 3 facsimile, group 4 facsimile, mixed mode, teletex,
Displays which of the terminal functions such as videotex, telex, audio-visual, and message handling system are provided.

The "user-user" information element is intended to be used for the communication of information between users, the content of this "user-user" information element being transferred transparently without being interpreted by ISDN. It is transmitted to the other user.

The "reason indication" information element is a message containing the information element (in this case, the release completion message REL_).
It is for notifying diagnostic information indicating the reason why COMP) is generated or the reason for an error that has occurred during the call setup procedure.

The "display" information element is for displaying various display information to the user from the ISDN.

Also, a session start positive response RS
The parameters included in the SP include, for example, as shown in FIG. 3C, a called terminal identifier that represents a terminal identifier (terminal identification information) of the called terminal, date / time information that represents date / time,
There is a service identifier for identifying the session service and session user data in which arbitrary user data, for example, a closed group ID, can be arranged.

As shown in FIG. 3D, the terminal identifier is a country code of up to 4 characters, a character "-", a subscriber number of up to 12 characters (ISDN number), and additional information of up to 4 characters. It consists of the character “=” and an abbreviation of 3 or more characters. The portion from the country code to the subscriber number is limited to a maximum of 15 characters, and the total length of the terminal identifier is fixed at 24 characters.

Therefore, when the terminal identifier is notified, the ISDN number of the terminal can be known.

The operation when the terminal having the call transfer mode set in the above configuration is called will be described.

The calling terminal sends a call setup message S to the ISDN.
The ETUP is sent to call the called terminal, and the ISDN sends a call setup message SETUP to the called terminal to call.
At this time, since the incoming call transfer mode is set in the destination terminal, as shown in FIG. 5, the incoming call transfer mode information indicating the incoming call transfer mode and the forwarding destination terminal identification information indicating the terminal identifier of the forwarding destination terminal are displayed. Release completion message REL_ with the added "user-user" information element
Send COMP (UUI) to reject the incoming call.

As a result, the ISDN sends a release completion message REL_COMP (UUI) with the "user-user" information element from the destination terminal to the source terminal,
Notify that the incoming call is rejected.

Therefore, the calling terminal ends the call setting operation. Next, the ISDN is sent to the call setup message SETUP for calling the transfer destination terminal in the specified call transfer mode.
To send to. If the transfer destination terminal can receive the call, a call is established between the source terminal and the transfer destination terminal, and the data transmission operation by the information channel becomes possible.

When the data transmission operation by the information channel is started, each layer is sequentially established from the lower layer to the upper layer in the same manner as described above, and when the session start acknowledgment response RSSP is received, the calling terminal While displaying the content of the called terminal identifier of the session start positive response RSSP on the operation display unit 6, for example,
A guidance message for confirming the continuation of the transmission operation "Do you want to transmit image information to this transfer destination terminal?" Is displayed to prompt the user to input the continuation of the transmission operation.

When the user makes an input designating the continuation of the transmission operation, the calling terminal executes the subsequent processing in the same manner as described above, and sends the document information to the transfer destination terminal. When the operation of transmitting the document information is completed, the call is disconnected and recovered, and the series of operation of transmitting the image information is completed. At the same time, the result of the image information transmission operation at that time is saved as a history.

On the other hand, when the user makes an input to the guidance message for confirming the continuation of the transmission operation, indicating that the transmission operation is not continued, as shown in FIG. , Session end command C
The SE is sent to terminate the image information transmission operation.

After that, the information channel termination procedure and the call disconnection recovery procedure are executed in the same manner as described above, and the series of operations is terminated. At the same time, the result of the image information transmission operation at that time is saved as a history.

In this way, the call transfer operation is performed.

In this case, for example, a communication result report as shown in FIG. 7 is formed and recorded and output by the plotter 5.

In this communication result report, the communication date and time,
Information of the other party (for example, ISDN number), communication result, presence / absence of incoming call transfer, and information of forwarding destination at the time of incoming call transfer are listed.

FIG. 8 shows an example of processing when making a call.

When the call setting message SETUP for making a call to the designated destination is transmitted (process 101), the message is received until the release completion message REL_COMP or the response message CONN is received (process 102, judgments 103, 104). NO loop). When the response message CONN is received, the result of judgment 104 is YES.
Then, the normal call processing is started.

When the release completion message REL_COMP is received and the result of judgment 103 is YES,
The release completion message REL_COMP indicates "user
It is checked whether the "user" information element is added (decision 105). When the result of decision 105 is YES, it is checked whether or not the content of the "user / user" information element is call transfer mode information (decision 10).
6).

When the result of judgment 106 is YES, it is checked whether the memory transmission mode is set (decision 107). When the result of the determination 107 is NO, the transfer process is activated (process 108).

When the result of the determination 107 is YES, the user's confirmation operation cannot be performed, so the contents of the "user / user" information element are saved (process 109).
The transmission operation ends in error (process 110), and that effect is saved as a communication history. When the result of determination 106 is NO, the process proceeds to step 109, the content of the “user / user” information element is saved, the transmission operation ends in error, and that effect is saved as a communication history. Also, judgment 10
When the result of 5 is NO, the process proceeds to step 110, the transmission operation ends in error, and that effect is saved as a communication history.

An example of the transfer process is shown in FIGS. 9 and 10.

The designated transfer destination is called (Processing 2
01), execute a predetermined call setup procedure (process 202),
When the information channel is established (step 203), the group 4 facsimile transmission procedure using this information channel is started.

When the lower layers up to the network layer of this group 4 facsimile transmission procedure are executed and established (process 204), the session start command CSS is sent (process 205) to set the connection of the session layer, and the other party. A session start positive response RSSP is received from the terminal (process 206)

Here, the contents of this session start positive response RSSP are analyzed to check whether or not the closed group ID is included in the session user data (decision 207). When the result of judgment 207 is YES, it is checked whether the content matches the closed group ID set in the terminal itself (judgment 208).

When the result of judgment 208 is YES, the subsequent document transfer operation is executed (process 2).
09), when the transfer operation is completed, the information channel termination procedure is executed (process 210), and the call is disconnected and recovered (process 2).
11). At this time, the communication operation has ended normally, so
The data representing that is saved as a history (process 2).
12).

When the content of the notified closed group ID does not match the closed group ID set in the terminal itself and the result of the determination 208 is NO, at that point, the procedure for terminating the information channel is performed. Is executed (process 21
3) The call is disconnected and recovered (process 214). At this time, since the communication operation has ended in error, the data indicating this is saved as a history (process 215).

When the closed group ID is not included and the result of determination 207 is NO, the contents of the called terminal identifier of the session start positive response RSSP are displayed on the operation display unit 6 as described above. At the same time, for example, a guidance message for confirming the continuation of the transmission operation "Do you want to transmit image information to this transfer destination terminal?" Is displayed (process 216). In that state, it is monitored whether or not there is an input from the user until a predetermined time has elapsed (NO loop of decisions 217 and 218).

If the user makes an input and the result of judgment 218 becomes YES before the elapse of a predetermined time, it is checked whether or not the input is for continuation (decision 21).
9). When the result of determination 219 is YES, the process proceeds to step 209 and the document transfer operation is performed.

When the result of the determination 219 is NO, the process moves to step 213 and the transfer operation is terminated. In addition, for example, when the user is absent and the result of judgment 217 is YES, the process 2
The transfer operation is terminated by moving to 13.

FIG. 11 shows an example of processing when receiving a call.

When the incoming call is detected, the received call setting message SETUP is analyzed (process 301), and it is checked whether or not it is possible to connect to the partner terminal (decision 302). When the result of the determination 302 is NO, the incoming call is received. Is ignored (process 303).

When the result of judgment 302 is YES, it is checked whether or not the call transfer mode is set (decision 304). When the result of judgment 304 is YES, the call transfer mode information representing the call transfer mode is displayed. , A release completion message REL_COMP (UUI) with a "user-user" information element, which is set with transfer destination terminal identification information indicating the terminal identifier of the transfer destination terminal
To reject the incoming call (step 305).

In this way, in this embodiment, when the called terminal responds with the release completion message REL_COMP (UUI) notifying the call transfer mode at the time of calling, first, when the memory transmission mode is set, Since the user's confirmation cannot be obtained, the processing ends with an error and the notified transfer destination terminal information and the like are saved as a communication history.

When the memory transmission mode is not set, the specified transfer destination is called and the image information transfer operation is performed. At this time, when it is determined that the closed group IDs do not match at the time of receiving the session start positive response RSSP from the partner terminal, the image information is not transferred and the error is not transmitted in order to keep the communication secret. finish. If the closed group IDs match, the image information is transferred.

If there is no closed group ID,
Since the called station identifier is presented to the user to inquire as to whether or not to continue communication, and after confirming the intention to continue, the image information is transferred, it is possible to keep the communication secret.

By the way, in the above-described embodiment, the call transfer function is realized by the terminal function, but the call transfer function of ISDN can also be utilized. An example of the procedure in that case is shown in FIG.

The calling terminal sends a call setup message SETUP to the ISDN to call the destination. The ISDN sends a call setup message SETUP to the designated destination terminal to call the destination terminal. The ISDN also sends a call setting acceptance message CALL_PROC to the calling terminal.

At this time, since the call transfer mode is set in the called terminal, the called terminal issues an additional information message INFO (transfer) to announce the call transfer service and notify the call transfer destination. To send to.

As a result, the ISDN sends the call setup message SETUP "which does not include the" calling number "information element to the designated call transfer destination.
Sends a disconnection message DISC to the called terminal to recover the call of the called terminal.

When the transfer destination terminal receives the call setting message SETUP "which does not include the" calling number "information element, it recognizes that this incoming call is in the call transfer mode, and the call transfer mode information indicating the call transfer mode. And a response message CON with a "user-user" information element including transfer destination terminal identification information in which the terminal identification information of the self terminal is set.
Send N (UUI) to ISDN. ISDN is a "user / user" with the same content as notified from the transfer destination terminal.
Response message CONN (UUI) with information element added
To the calling terminal. As a result, an information channel is established between the calling terminal and the transfer destination terminal.

Then, the calling terminal recognizes that it has connected to the transfer destination terminal by the call transfer, and uses the content of the transfer destination terminal identification information of the "user / user" information element received at that time as the terminal identification information of the destination terminal. , And in that state, the image information transmission operation on the information channel is performed. When the image information transmission operation is completed, the call is disconnected and recovered, and the series of operations is completed.

In this way, in this embodiment, the transfer destination terminal notifies the calling terminal of the terminal identification information of its own terminal, and the calling terminal sends the notified terminal identification information of the transfer destination terminal. Since the group 4 facsimile transmission procedure on the information channel is executed by using the same, it is possible to avoid a situation where the called terminal identifiers do not match when setting the session connection, and to perform an appropriate image information transmission operation.

FIG. 13 shows an example of processing at the time of calling according to this embodiment.
And shown in FIG.

A call setting message SETUP for making a call to the designated destination is transmitted (process 401), and it is monitored whether a response message CONN or a release completion message REL_COMP is received before a predetermined time elapses (process 402). , NO loop of decisions 403, 404, 405).

When the response message CONN is received and the result of the determination 403 is YES, it is checked whether or not the response message CONN includes the "user / user" information element (determination 406), and the determination 4
When the result of 06 is NO, the process shifts to a normal calling process.

When the result of judgment 406 is YES, it is checked whether or not the call transfer mode is notified (decision 407). When the result of judgment 407 is NO, the "user / user" information element is saved. Then (process 408), the process proceeds to normal call processing.

When the call transfer mode is notified and the result of judgment 407 is YES, it is checked whether or not the memory transmission mode is set at that time (decision 409). When the result of the determination 409 is NO, an information channel is established (process 410), and the data transfer operation of the above-mentioned incoming call transfer mode is executed using the established information channel (process 411).

When the data transfer is completed, the information channel is terminated (process 412) and the call is disconnected and recovered (process 41).
3) Then, the history data representing the normal end is saved (process 414) and the series of operations is ended.

Further, when the result of the judgment 409 is YES, the call disconnection recovery operation is executed at that time (process 415), and at this time, the history data representing the error end is saved (process 416). , End a series of operations. When the result of the determination 404 is YES,
If the result of determination 405 is YES, the process proceeds to step 416 and ends in error.

FIG. 15 shows an example of processing at the time of an incoming call according to this embodiment.
Shown in.

When the incoming call is detected, the received call setting message SETUP is analyzed (process 501) and it is checked whether or not it is possible to connect to the partner terminal (decision 502). Judgment 502
When the result is NO, the incoming call is ignored (process 503).

When the result of judgment 502 is YES, "calling number" is added to the received call setting message SETUP.
Check whether the information element is included (decision 50)
4). When the result of judgment 504 is YES, it is checked whether or not the call transfer mode is set (decision 5).
05). When the result of the determination 505 is NO, the process shifts to a normal incoming call process.

When the result of the judgment 505 is YES, as described above, the additional information message INFO (transfer) for expressing the reception of the call transfer service and notifying the call transfer destination is transmitted (process 506) and the call is made. Is restored by disconnection (process 507) and a series of operations is ended.

When the received call setting message SETUP does not include the "calling number" information element, the judgment is 50.
When the result of 4 is NO, the call is transferred to the transfer destination terminal of the call transfer, and as described above, the transfer destination terminal identification in which the call transfer mode information indicating the call transfer mode and the terminal identification information of the self terminal are set. Response message CONN (UU) with a "user-user" information element containing information
I) is sent to ISDN (process 508).

Then, a response confirmation message CONN_A
CK is received (process 509), the information channel is established (process 510), the group 4 facsimile transmission procedure is executed on the information channel to transfer information (process 5).
11). When the information transfer is completed, the information channel is terminated (process 512), the call is disconnected and recovered (process 513), and a series of operations is terminated.

In this embodiment, the user has not confirmed the information transfer in the call transfer mode, but such an operation may be carried out. Further, although the incoming call transfer mode is not performed during the memory transmission, the incoming call transfer mode may be performed during the memory transmission.

Further, in the above-mentioned embodiment, the procedure executed by ISDN when receiving the request for the call transfer service is as follows.
Although the case of the procedure specific to ISDN which does not comply with CCITT recommendation is shown, the present invention can be similarly applied to the case where ISDN uses another procedure.

Further, although the present invention is applied to the group 4 facsimile apparatus in the above-mentioned embodiments, the present invention can be similarly applied to other ISDN terminal apparatuses.

[0107]

As described above, according to the present invention,
Since the call transfer is realized not by the ISDN function but by the function unique to the terminal, inconsistency between the terminals can be prevented, and the information transfer operation from the calling terminal to the transfer destination terminal is appropriately performed. Further, when the call transfer is notified from the ISDN, the calling terminal, in order to replace the notified identification information of the call transfer destination with the identification information of the call destination at the time of information transfer, the calling terminal and the transfer destination terminal. Therefore, it is possible to prevent inconsistency between them, and therefore, an effect that the information transfer operation between the calling terminal and the transfer destination terminal is appropriately performed is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a group 4 facsimile apparatus according to an embodiment of the present invention.

FIG. 2 is a time chart showing an example of a transmission procedure of a group 4 facsimile apparatus.

FIG. 3 is a schematic diagram showing formats of various signals.

FIG. 4 is a time chart showing the operation of the call transfer mode according to the embodiment of the present invention.

FIG. 5 is a schematic diagram showing an example of the contents of a “user-user” information element.

FIG. 6 is a time chart showing another case of the operation of the call transfer mode according to the embodiment of the present invention.

FIG. 7 is a schematic diagram showing an example of a communication result report.

FIG. 8 is a flowchart showing an example of processing when making a call.

FIG. 9 is a flowchart showing a part of an example of a transfer process.

FIG. 10 is a flowchart showing another part of an example of the transfer process.

FIG. 11 is a flowchart showing an example of processing when a call is received.

FIG. 12 is a time chart showing an operation example of a call transfer mode according to another embodiment of the present invention.

FIG. 13 is a flowchart showing a part of another example of processing at the time of calling.

FIG. 14 is a flowchart showing another part of another example of the processing at the time of calling.

FIG. 15 is a flowchart showing another example of processing when receiving a call.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location H04L 29/08 H04M 1/00 E 7117-5K

Claims (5)

[Claims] 1. ISDN using ISDN as a transmission path
In the transmission control method for a terminal device, a storage means for storing terminal identification information of a call transfer destination is provided, and when the call transfer mode is set when the call reception is detected, the call reception terminal stores the call received in the storage means. In the state of notifying the transfer destination terminal identification information, the release completion message is sent to reject the incoming call, and the calling terminal receives the release completion message at the time of calling,
Further, when the release completion message includes the terminal identification information of the call transfer destination, the notified call transfer destination is called to transfer the information.
Transmission control method of N terminal device. 2. The calling terminal calls the call transfer destination to establish an information channel, and when the session user data of the procedure signal received from the partner terminal in the session procedure includes a closed group number. , The closed group number preset in the terminal is compared with the notified closed group number, and if they match, the subsequent information transfer operation is executed, and if they do not match, the information is 2. The transfer operation is terminated.
A transmission control method for an ISDN terminal device as described. 3. The calling terminal displays the called terminal identifier included in a procedure signal received from the partner terminal in the session procedure by calling the call transfer destination, an information channel is established, and transfers the call to the user. When the continuation of the operation is confirmed and the continuation of the transfer operation is designated, the subsequent information transfer operation is executed, and when the discontinuity of the transfer operation is designated,
The transmission control method for an ISDN terminal device according to claim 1, wherein the information transfer operation is terminated. 4. The ISDN terminal device according to claim 2, wherein the calling terminal stores the notified call forwarding destination in the communication history information when the information forwarding operation is terminated. Transmission control method. 5. ISDN using ISDN as a transmission line
In the transmission control method of a terminal device, when an ISDN is notified of a call transfer at the time of call origination, the notified identification information of the call transfer destination is replaced with the identification information of the call destination at the time of information transfer to operate. A transmission control method for an ISDN terminal device, comprising: