JPH09200353A - Communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent missing of important data due to the incoming call transfer service by adopting the configuration that no incoming call transfer service is conducted when inter-user information is included in a message. SOLUTION: The system is made up of a CPU 12 to conduct control and management of the entire equipment, a ROM 14 being a read only memory storing programs executed by the CPU 12, a 1st RAM 16 used to store control information (counter, flag, data or the like) for the CPU 12 and various data, and a real time clock 18 used for information of a current time and a timer. When an incoming call is received by a called party and the call is transferred (incoming call transfer), whether or not user-user information (UUI) is included in a received setup message is discriminated and when no UUI is included, the incoming call transfer is conducted but when the UUI is included, the incoming call transfer is not conducted.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a so-called ISDN.
The present invention relates to a communication device that is connected to a network (Integrated Service Digital Network) and can perform communication.

[0002]

2. Description of the Related Art With the development of digital communication technology, ISD
The use of N networks is expanding. By the way, this ISD
There is a call forwarding service among the additional services provided by the N network.

In this call transfer service, when a call received is desired to be transferred to another party, the called device (transfer source device) communicates with an ISDN network (hereinafter abbreviated as "network"). The call can be transferred to the target transfer destination. In addition, this service transfers after responding (after making a call etc.),
Different from call forwarding.

In addition, in the call transfer service, transfer can be requested for each incoming call (the communication device can determine the presence or absence of the transfer), and the transfer destination can be changed for each incoming call (transfer). The communication device can set the destination), and
It is possible to specify whether or not to send a talkie that notifies transfer for each incoming call.

Here, the IS between the user B and the user C.
Table 1 below shows communication conditions performed through the DN network.

[0006]

[Table 1] In Table 1, user A is a called user (transfer source user), user B is a calling user, and user C is a transfer destination user.

As shown in Table 1, the user-user information (UUI) sent by the sender user B is not transferred to the transfer destination user C (the ISDN network discards it). The same applies to the destination subaddress. Also, regarding the sender number and calling subaddress,
The transfer destination user C is notified as it is, but the caller number and the calling subaddress of the transfer source are not notified at all (because there is no means for notifying).
In Japanese Patent No. 206270, the transfer source number can also be notified to the transfer destination.

Further, UUI is capable of exchanging data of up to 128 octets using a call control protocol of D channel (control channel), and the charge is as low as 0.4 yen per message. , It can be used very effectively when sending a small amount of data frequently. That is, since UUI does not use the B channel (information channel), it is possible to perform communication at a very low charge.

[0009]

However, at present,
There are various restrictions (restrictions) on the provided call transfer service, and the UU sent by the caller is included in the restrictions.
There is a situation in which I (user / user information) cannot be transferred to the transfer destination, which causes the following problems.

That is, as described above, the UUI is added to the call.
, It is very likely that the UUI contains very important information about the communication. If the call transfer service provided by the current INS network is used, the UUI transfers the information. There is a big problem that very important information is lost because it will not be delivered first.

Further, the sender does not know at all the fact that the UUI containing such important information has not reached the transfer destination (strictly speaking, it does not even know that the call has been transferred). Therefore, there is a high possibility that the information entered in the UUI will be misunderstood as having arrived at the intended other party.

Further, the communication transferred by the incoming call is not only completely useless communication (useless communication time, waste of communication charge), but also causes the sender to have an incorrect misunderstanding (data transfer completed successfully). , Becomes a very big problem.

In consideration of the above facts, the present invention makes a predetermined judgment before the call transfer service is executed,
In addition to preventing the loss of important information stored in the UI,
An object of the present invention is to provide a communication device that eliminates wasteful communication without misunderstanding that the information entered in the UUI has reached the intended party.

[0014]

In order to achieve the above object, the invention according to claim 1 is connected to an ISDN network,
In a communication device having a function of executing a call transfer service provided by the ISDN network, the call transfer service is not performed when the call setting message of the caller includes information between users. .

According to the first aspect of the present invention, when the call setup message from the sender is received, and if this message includes the information between users, the call transfer service is not provided. As a result, the call including the user-to-user information is not transferred, so that valuable data will not be lost by the call transfer service. Further, it is possible to avoid the source from misunderstanding that the inter-user information is transferred to the transfer destination.

According to the invention of claim 2, in a communication device which is connected to an ISDN network and has a function of executing a call transfer service provided by the ISDN network, a call setting message of a caller includes information between users. If so, the information between the users is analyzed, and it is determined whether there is a communication problem even if the information is not transferred to the transfer destination. If it is determined that there is no communication problem, the call transfer service is provided. Is permitted and the call transfer service is not provided when it is determined that there is a problem.

According to the second aspect of the present invention, when the call setting message of the caller includes the information between users, the information between users is analyzed and communication is performed even if the information is not transferred to the transfer destination. To determine if there is a problem. If it is determined that there is no problem in communication, the call transfer service is permitted, and if it is determined that there is a problem, the call transfer service is not executed. As described above, since it is determined whether or not to execute the call transfer service based on the analysis result of the information between users, it is possible to prevent waste of communication as compared with the case where the call transfer service is uniformly executed.

The invention of claim 3 is claim 1 or claim 2.
In the present invention, when the call transfer service is not executed, the fact that the call transfer service is not executed is notified to the sender.

In the third aspect of the invention, when the call transfer service is not executed, the fact that the call transfer service is not executed is notified to the sender. As a result, the sender can know that the call transfer service could not be executed, and the subsequent response can be facilitated.

According to a fourth aspect of the present invention, there is provided a communication device which is connected to an ISDN network and communicates with a partner device having a function of executing a call transfer service provided by the ISDN network,
If a call setup message containing user-to-user information is sent to the transfer-destination partner and a notification that the call-forwarding service is rejected is received from the transfer-source device, the recalling procedure is performed without including the user-to-user information. It is characterized by being performed automatically.

According to the fourth aspect of the invention, when the call setting message including the user-to-user information is transmitted to the other party of the transfer source and then the notification that the call transfer service is rejected is received from the transfer source, the user is notified. Recall procedure is automatically performed without including information about the interval. As a result, it is possible to reliably transfer the data to the other party to whom the communication is intended.

According to the invention of claim 5, in the invention of claim 4, when a notification indicating that the call transfer is rejected is received from the transfer source, whether to call again without including the information between users is determined. It is characterized in that it is decided based on the input instruction.

According to the fifth aspect of the present invention, when the call setting message including the information between users is transmitted to the other party of the transfer source and then the notification that the call transfer service is rejected is received from the transfer source, the user is notified. Whether or not to re-call without including the inter-arrival information is determined based on the input instruction. This makes it possible to prevent the loss of very important UUI information.

[0024]

DETAILED DESCRIPTION OF THE INVENTION A facsimile apparatus according to an embodiment of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows the configuration of a facsimile apparatus according to the first embodiment.

As shown in FIG. 1, the present facsimile machine has a CPU (Centra) for controlling and managing the entire machine.
processing unit) 12, a read only memory (ROM) 14 which is a read-only storage device in which a program executed by the CPU 12 is stored, and the CPU 12
A first RAM 16 used for storing control information (counters, flags, data, etc.) and various data, and a real-time clock 18 used as a notification of the current time and as a timer. Each is connected to a system bus 10 for passing data.

The system bus 10 has a keyboard 20 used as an input device for information from an operator.
And a display 24 for displaying various information to the operator are connected. These devices are used as user interface devices that control the interface with the operator, and these devices allow the operator and the facsimile device to communicate with each other.

The system bus 10 also has an ISDN interface control unit 26 for executing interface control with the ISDN network, and a first unit for temporarily storing received data and transmitted data by the control unit 26. A second RAM 28, a coder / decoder 30 for encoding or decoding image information, and a third RAM 32 used for storing image information are connected. These components exchange data with each other, as indicated by the thick arrows in the figure.

Further, the third RAM 32 has a scanner 36 for converting reflected light into digital data while irradiating light on an original (not shown) for facsimile transmission.
And a printer 34 for printing out the decoded image information stored in the RAM 32. The scanner 36 and the printer 34 are also connected to the system bus 10 and controlled by the CPU 12.

Next, the flow of data in the facsimile apparatus will be briefly described. First, in the case of transmission, the scanner 36 reads a document, and the read image information is stored in the RAM 3
2 is stored. Thereafter, the coder 30 compresses the image information into coded information and stores it in the RAM 28. Then, the accumulated encoded information is transmitted to the remote device of the other party via the ISDN interface control device 26.

Next, in the case of reception, the data sent from the remote device of the other party is stored in the RAM 28 via the ISDN interface control device 26. Next, the accumulated data is expanded by the decoder 30, and the expanded data is accumulated in the RAM 32 as image information. The accumulated image information is transferred to the printer 3
4 is printed.

In the above example, the flow of transmitted / received data has been described, but of course, without communicating with a remote device, image information read by, for example, the scanner 36 is temporarily stored and then printed out by the printer 34. Yes (corresponding to the copy function).

Here, the call transfer service utilized in the facsimile apparatus according to the present invention will be described.

The call transfer service provided by the ISDN network is a function for transferring a call to another user without answering when there is a call, and after the call is answered (after making a call or the like). Be careful because it is different from the call forwarding or forwarding call. Transfer can be requested for each incoming call (whether or not transfer is performed can be determined by the communication device for each incoming call), and the transfer destination can be changed for each incoming call (the communication device can set the transfer destination). Furthermore, it is possible to specify whether or not to send a torch that notifies transfer for each incoming call.

The signal sequence in the call transfer service will be briefly described with reference to FIG.

As shown in FIG. 2, a call setup message (SET UP) is sent to the network in response to a call origination request from the sender (user B), and the network sends the callee number information element in the call setup message to the other party. Call the called party (user B) (send SET UP). User A attaches the forwarding number to the additional information message (INFO) and forwards it in order to forward (call forward) this call. The network is the designated transfer destination (user C).
At the same time as calling (the SET UP is sent), the release message (REL) is sent to the user A and the call (call to the user A) is terminated. Upon receiving the REL, the user A sends a release completion message (REL COMP) to end the call. Then, the user C sends a call message (ALERT) in response to the call setup message, and the network receiving the message notifies the user A of that fact by an additional information message.

Next, the processing of the call transfer service of the facsimile apparatus according to the first embodiment will be described with reference to the flowchart of FIG.

In the first embodiment, the called party (user A
When the call is transferred (call transfer) when there is an incoming call, it is determined whether or not the received call setting message includes UUI, and if it does not include UUI, the call transfer is performed. However, if it is included, the call transfer is not performed. Not carrying out the call transfer service may be processing (countermeasures or countermeasures) of rejecting the call completely (not accepting it) or receiving it by itself without transferring it. If you refuse completely, from the sender (after taking any action)
There is a possibility of returning by redialing (incoming call transfer can be performed normally), and if you receive it yourself without transferring it, after receiving it, you can make a call to the transfer destination separately to ensure normal communication. It is expected to be realized (details are omitted because it is described in another invention).

As shown in FIG. 4, when there is an incoming call (incoming call), the received call setting message (SET UP) is analyzed (step 100).

Next, the possibility of communication is confirmed (step 102). The communication possibility confirmation is to determine whether the incoming call may be accepted or whether the incoming call is addressed to itself. For example, if there is a called number information element or a called subaddress information element included in SETUP, it can be compared with the calling number or calling subaddress defined within itself, and an incoming call can be made only when they match. In addition, it is possible to judge whether or not there is communication capability (whether they match) by the transfer capability information element, the higher layer compatibility information element, and the lower layer compatibility information element, and to make an incoming call only when they match. it can.

As a result of the communication possibility confirmation, if the communication possibility is confirmed (Yes at Step 102), it is checked whether or not the call transfer is performed (whether or not the call transfer is set). (Step 104). When it is determined that the call is transferred (Yes in step 104),
It is checked whether or not there is a UUI information element in the SETUP (if the call is not transferred, it is received by itself (the call is accepted), and the process proceeds to such next processing).

If there is no UUI (step 106)
Negative determination), since the incoming call transfer is performed, the process proceeds to the next incoming call transfer process. On the other hand, when the UUI exists (Yes at Step 106), the incoming call transfer is not performed, and in this case (flow chart), the call (incoming call) is ignored.

On the other hand, as a result of the confirmation of the communication possibility in step 102, if the communication possibility is denied (step 104 negative judgment), the incoming call processing is ended. That is, no call transfer is performed, and in this case (flow chart), the call (call) is ignored.

When it is determined in step 104 that the incoming call transfer is not performed (negative determination in step 104), the process proceeds to the next process.

As described above, according to the present invention, since the call including the UUI is not transferred, the valuable data is not lost by the call transfer service. Further, there is a problem in that the sender (user B) according to the above-mentioned conventional technology misunderstands that the UUI is transferred to the destination (user C) (actually, the network does not automatically delete and transfer). The point can be solved.

(Second Embodiment) In the call transfer service of the facsimile apparatus according to the second embodiment, when the callee (user A) receives a call, the call is transferred (call transfer). In this case, it is determined whether or not the received call setup message includes UUI, and if it is not included, the call transfer is performed.
The content is analyzed, it is determined whether or not the content needs to be transferred to the transfer destination, and if it is determined that the content needs to be transferred, the incoming call transfer is performed.

Next, the call transfer service of the second embodiment will be described with reference to the flowchart of FIG.

As shown in FIG. 5, when there is an incoming call (incoming call), the received call setting message (SET UP) is analyzed (step 110).

Next, the possibility of communication is confirmed (step 112). As a result of the communication possibility confirmation, if the communication possibility is confirmed (Yes at Step 112), it is checked whether or not the call transfer is performed (whether or not the call transfer is set) (Step S112). 114).

Regarding the judgment method (judgment standard) as to whether or not the transfer is necessary, for example, a flag is provided in the UUI information, and the UUI information is sent to the other party at the timing of transmitting the UUI from the calling side. In the case of information to be notified without fail, the flag is turned on when it is sent, and in the case of information that may otherwise be discarded on the way, it is sent with the flag turned off. The callee (user A) determines whether the transfer is necessary as described above by determining whether the flag is on or off.

When it is determined that the incoming call is transferred (Yes at Step 114), it is checked whether or not the UUI information element exists in the SETUP (Step 116;
If the call is not transferred, the call is received by itself (the call is accepted), and the process proceeds to such next process).

If there is no UUI (step 116)
Negative determination), since the incoming call transfer is performed, the process proceeds to the next incoming call transfer process. On the other hand, if the UUI exists (Yes at Step 106), the content is analyzed and it is determined whether there is no problem even if the UUI is deleted (Step 1).
18).

It should be noted that the contents of the UUI basically include important data (using the UUI,
Because it transfers data), but sometimes
There may be data of less important contents (about information level). Therefore, when it is determined that the call transfer service is used, even if the call is discarded in the network, the actual data communication (or call) is hardly affected, the call transfer is performed as it is.

When it is determined that the UUI may be deleted (Yes at Step 118), the following process is executed. If it is determined that there is a problem when the UUI is deleted (No at Step 118), the call transfer is not performed, and in this case (flow chart), the call (call) is ignored.

On the other hand, as a result of the confirmation of the communication possibility in step 112, if the communication possibility is denied (step 114 negative judgment), the incoming call processing is ended. That is, no call transfer is performed, and in this case (flow chart), the call (call) is ignored. If it is determined in step 114 that the call transfer is not performed (step 114, negative determination), the process proceeds to the next process.

As described above, according to the present invention, whether or not the incoming call is transferred is determined according to the contents of the UUI.
There is an effect that valuable data will not be lost by the call transfer service.

(Third Embodiment) Although the call transfer service of the facsimile apparatus according to the third embodiment is intended to carry out the call transfer described in the first embodiment, the UU
This is to notify the caller (user B) of the fact that the call transfer was not performed because it includes the I information.

Next, the call transfer service of the third embodiment will be described with reference to the flowchart of FIG.

As shown in FIG. 6, when there is an incoming call (incoming call), the received call setting message is analyzed (step 120).

Next, the communication possibility is confirmed (step 122). As a result of the communication possibility confirmation, if the communication possibility is confirmed (Yes at Step 122), it is checked whether or not the incoming call is transferred (Step 124).

When it is determined that the incoming call is transferred (Yes at Step 124), it is checked whether or not the UUI information element exists in the SETUP (Step 12).
6).

If no UUI exists (step 126)
Negative determination), since the incoming call transfer is performed, the process proceeds to the next incoming call transfer process. On the other hand, when the UUI exists (Yes at step 126), the call transfer is not performed, and the reason (for example, # 21 described later is used) is displayed and the release completion message (REL COMP) is sent. Create and send (step 128).

On the other hand, as a result of the confirmation of the communication possibility in step 122, if the communication possibility is denied (step 122 negative judgment), the incoming call processing is ended. That is, no call transfer is performed, and in this case (flow chart), the call (call) is ignored. When it is determined in step 124 that the incoming call transfer is not performed (negative determination in step 114), the process immediately proceeds to the next process without determining whether or not there is a UUI in step 126.

At present, many error displays (reasons) are defined. For example, in step 128, the release completion message (R) is sent using # 21 (communication refusal) or # 63 (other service or option unavailable class) in the defined error display.
EL COMP) is sent and the call (incoming call) is rejected. When the caller (user B) receives the reason display, the caller knows that the other party tried to perform the call transfer but did not perform the call transfer because the UUI information was included. The operator can be notified by displaying the received error on a display device such as a panel. Here, a sequence for notifying the other party of the above error display is shown in FIG.

As described above, according to the present invention, since the caller (user B) is notified that the call transfer was not performed because it includes the UUI information, valuable data is transferred by the call transfer service. It will not be missing,
This has the effect of facilitating the subsequent response by the user B.

(Fourth Embodiment) Although the call transfer service of the facsimile apparatus according to the fourth embodiment is intended to carry out the call transfer described in the third embodiment, the UU
In the caller (user B) who has been notified that the call transfer was not performed because it includes the I information, the recall procedure is automatically performed without including the UUI.

As described above, for example, the sender (user B)
In, when a release completion message (REL COMP) including a reason display that means "call transfer cannot be performed because UUI is included" such as # 21 or # 63 is received (the call is rejected), the calling terminal , The UUI information is automatically deleted, and the call setup message (SET UP) is sent again (the re-calling procedure is started).

Next, the call origination process of the fourth embodiment will be described with reference to the flowchart of FIG.

As shown in FIG. 7, when making a call (calling), various information elements (transmission capability, called number,
Destination sub-address, calling number, calling sub-address, higher layer compatibility, lower layer compatibility, user / user information, etc.) and create a call setup message (SET UP),
It is sent (step 130).

Next, it waits for a response message from the network (No at step 132). Strictly speaking, after sending SETUP, a timer (T.
303) is set and it is determined whether or not there is a response within the specified time, which is omitted in this flowchart.

When a message is received (step 13)
2 affirmative judgment), the received message is the call setting acceptance (CA
LL PROC) or a call (ALERT) message (step 134 affirmative judgment; step 136 affirmative judgment), the process enters the message reception waiting state again (step 132). Here, response message (CONN) or release completion (REL COMP)
Wait for a response until you receive the message.

The received message is the response message (CO
If it is NN) (Yes at step 138), since the connection with the partner device is established, the process proceeds to the next process (transmission operation).

If the received message is other than the release completion message (NO at step 140), an invalid message has been received, and the process proceeds to the abnormal process. Strictly speaking, at this timing, there are other (non-abnormal) messages that may be received (for example, status display), but they are omitted here.

When the received message is the release completion message (Yes at Step 140), the reason display (Cause) information element is analyzed to determine whether the content is # 21 (Step 142). ).

If the reason display information element is # 21 (Yes at step 142), the UUI information element is deleted (step 144), and the process returns to step 130 to resend the call setup message (recall procedure). carry out.

When the reason display information element is other than # 21 (No determination in step 142), some other abnormality may be considered on the receiving side, and therefore the processing shifts to that.

As described above, according to the present invention, there is an effect that the communication is surely transferred to the intended destination (transfer destination).

(Fifth Embodiment) In the fourth embodiment, the expression (described) of "the UUI is automatically deleted" is made by the caller side, but, of course, the UUI has a very important meaning. A problem arises in the case of having (which is always required in the communication).

Therefore, in the fifth embodiment, the call transfer described in the third embodiment is tried to be performed.
The call transfer is not performed because it includes the I information, and the caller (user B) notified to that effect determines whether to perform the recall procedure without including the UUI according to the operator's instruction. Is.

Next, the call origination process of the fifth embodiment will be described with reference to the flowchart of FIG.

As shown in FIG. 8, when making a call (calling), various information elements (transmission capability, called number,
Destination sub-address, calling number, calling sub-address, higher layer compatibility, lower layer compatibility, user / user information, etc.) and create a call setup message (SET UP),
It is sent (step 150).

Next, it waits for a response message from the network (step 152, negative determination). When a message is received (Yes at Step 152), if the received message is a call setting acceptance (CALL PROC) or call (ALERT) message (Step 154 affirmative judgment; Step 156 affirmative judgment), waiting for message reception again. The state is entered (step 152). Here, the response is waited until the response message (CONN) or the release completion (REL COMP) message is received.

The received message is the response message (CO
NN) (Yes in step 158), since the connection with the partner device is established, the process proceeds to the next process (transmission operation).

If the received message is other than the release completion message (step 160, negative determination), since an invalid message has been received, the process proceeds to the abnormal processing.

When the received message is the release completion message (Yes at Step 160), the reason display (Cause) information element is analyzed to determine whether the content is # 21 (Step 162). ).

If the reason display information element is # 21 (Yes at Step 162), the fact is displayed (error display) on the display 24 (Step 164). If the reason display information element is other than # 21 (No at step 162), some other abnormality may be considered on the receiving side, and the process proceeds to that process.

Next, when an instruction from the operator is awaited and this instruction deletes the UUI and carries out the recalling call (Yes at step 166), the UUI information element is deleted (step 164) and the process returns to step 150. And resend the call setup message (recall procedure). The instruction from the operator may be, for example, the keyboard 2
It is determined by pressing the 0 key.

On the other hand, if the instruction from the operator does not continue (NO at step 166), that is, if the call is canceled, the call-out operation is terminated. In this case, the operator gives an instruction to cancel by pressing the stop key, for example.

Strictly speaking, in the above processing, an error is displayed, a timer is set in a state of waiting for an instruction from the operator, and if no instruction is given within a prescribed time, either one (for example, cancel) is automatically set. You may make it shift to a process.

As described above, according to the present invention, since it is left to the calling operator whether or not to shift to the recalling procedure,
It is possible to prevent the loss of very important UUI information.

In each of the above-described embodiments, an example of application to a facsimile machine is described, but it can be used (utilized) for all communication terminals that are connected to the ISDN network and can perform communication.

[0091]

As described above, according to the first aspect of the present invention, when a call setup message is received from a sender, if this message includes user-to-user information, a call transfer service is provided. Since it is not performed, valuable data will not be lost by the call transfer service, and it is possible to avoid the source from misunderstanding that the user-to-user information is transferred to the transfer destination. The effect is obtained.

According to the invention of claim 2, it is judged whether or not there is a communication problem even if the information between the users is not transferred to the transfer destination, and if it is judged that there is no communication problem, the call transfer service is provided. Since the call transfer service is not executed when it is determined that there is a problem, the above effect and a further effect of preventing waste of communication can be obtained.

According to the third aspect of the present invention, when the call transfer service is not executed, the caller is notified that the call transfer service has not been executed. Therefore, the call transfer service is executed by the caller. The additional effect of being able to know what was not possible and making it easier to respond afterwards is obtained.

According to the invention of claim 4, when the notification that the call transfer service is rejected is received from the transfer source,
Since the recalling procedure is automatically performed without including the information between the users, it is possible to reliably transfer the call to the intended recipient.

According to the fifth aspect of the present invention, when the notification that the call transfer service is rejected is received from the transfer source, it is input whether or not to recall without including the information between users. Since the decision is made based on the instruction, it is possible to prevent the loss of very important information between users.
The effect is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a facsimile apparatus according to the present invention.

FIG. 2 is a diagram showing an operation sequence of a call transfer service.

FIG. 3 is a diagram showing a sequence for notifying the other party of an error display.

FIG. 4 is a flowchart showing a processing flow of a call transfer service of the facsimile apparatus according to the first embodiment.

FIG. 5 is a flowchart showing a processing flow of a call forwarding service of the facsimile apparatus according to the second embodiment.

FIG. 6 is a flowchart showing a processing flow of a call transfer service of the facsimile apparatus according to the third embodiment.

FIG. 7 is a flowchart showing a processing flow of a call transfer service of the facsimile apparatus according to the fourth embodiment.

FIG. 8 is a flowchart showing a processing flow of a call transfer service of a facsimile apparatus according to a fifth embodiment.

[Explanation of symbols]

 12 CPU 14 ROM 20 keyboard 24 display 26 ISDN interface control device

Claims (5)

[Claims] 1. A communication device which is connected to an ISDN network and has a function of executing a call transfer service provided by the ISDN network, wherein the call setting message of the caller includes information between users. Is a communication device characterized by not performing a call transfer service. 2. A communication device which is connected to an ISDN network and has a function of executing a call transfer service provided by the ISDN network, wherein the call setting message of the caller includes information between users. Analyzes the information between the users, determines whether there is a communication problem even if the information is not transferred to the transfer destination, and if it determines that there is no communication problem, permits the call transfer service. A communication device, which does not provide a call transfer service when it is determined that there is a problem. 3. The communication device according to claim 1, wherein when the call transfer service is not executed, the caller is notified that the call transfer service has not been executed. 4. A communication device, which is connected to an ISDN network and communicates with a partner device having a function of executing a call transfer service provided by the ISDN network, the call setting message including user-to-user information being a transfer source. A communication device characterized in that, when a notification indicating that the call transfer service is rejected is received from the transfer source after the call is sent to the partner device, the recalling procedure is automatically performed without including the information between the users. 5. When receiving a notification that the call transfer is rejected from the transfer source, whether to re-call without including the information between users is determined based on the input instruction. The communication device according to claim 4, which is characterized in that.