JP3267687B2 - Communication control method between ISDN network and terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a communication control method between an ISDN network and terminals when connected to one line of a DN network.

[0002]

2. Description of the Related Art In an ISDN, when a normal basic interface is used, a maximum of eight terminal devices can be connected to one subscriber line by bus.

When a plurality of terminal devices are connected to one line as described above and, for example, there is only one operator, when a call is received, a specific one close to the location of the operator is received.
It is convenient if the table always responds and communicates.

As described above, one method of responding to a specific one terminal device at the time of an incoming call is to have the calling side specify the subaddress of the called terminal device when setting the destination. is there.

As another method, an MSN (Multiple Subscriber) of an ISDN network is used.
Number) service is conceivable.
In the MSN service, an address different from the address assigned to the subscriber line is registered as an address of an arbitrary terminal device. Using this service, register another address in one terminal device that you want to respond,
By having the calling party call the other address when setting the destination, one desired terminal device can respond.

However, both of the above two methods require a special setting operation on the calling side, and the response terminal cannot be arbitrarily set by the procedure of the called side.

As another method for responding to a desired one terminal device, for example, as disclosed in Japanese Patent Application Laid-Open No. 2-156773, the response speed of a specific one terminal device to an incoming call is increased. There is a way to do that. That is, ISD
In the call connection procedure of N, when a plurality of terminal devices receive a setting message “SETUP” and receive a call, one terminal device that responded to the response message “CONN” earliest is
The call is connected. Therefore, by setting the response speed of a desired terminal device faster than that of the other terminal devices, one terminal device can always communicate.

However, according to this method, if the response speed of the other terminal device is very high, and if the response speed cannot be set faster than that, the desired terminal device cannot be made to respond.

[0009]

As described above, conventionally,
There has been a problem that a desired one terminal device cannot respond and perform communication at the time of an incoming call due to a procedure on the called side.

[0010] The present invention solves the above problem and provides a communication control method between an ISDN network and a terminal which can always respond and communicate with a desired one terminal at the time of an incoming call by a treatment of the called side. The purpose is to provide.

[0011]

According to the present invention, one of a plurality of terminal apparatuses is provided with a terminal identifier (hereinafter referred to as TEI; Terminal End Point I) from a network side.
When a check request is received, the TEI check response set for its own terminal is executed together with the TEI check response set for the other terminals. Things.

[0012]

In the ISDN network, each terminal on one line has a TEI.
Check request is sent and TEI notified from each terminal
And if the received TEIs overlap, T
EI allocation error is determined and the corresponding terminal TEI
Is released. When each terminal receives the above check request from the network, it responds with the TEI set for itself.

As described above, when one terminal responds to another terminal's TEI as a TEI check response, the network receives the same TEI redundantly, and the other terminal releases the TEI. I will let you.

When a call arrives on the line, the other terminal that has released the TEI executes a predetermined procedure for acquiring the TEI,
Answer the incoming call. On the other hand, the one terminal holding the TEI responds immediately upon receiving the call. As a result, when an incoming call is received, the one terminal preferentially responds and performs communication.

[0015]

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

FIG. 1 shows an ISDN according to an embodiment of the present invention.
This shows the device configuration of the terminal equipment.
Are respectively connected to an in-home bus of an ISDN subscriber line, and the in-home bus is
It is connected to the SDN network. The terminal devices 1 and 2 are facsimile devices and various data transmission devices.

In ISDN, each terminal used has a T
EI is set. The TEI may be fixedly set in the device in advance, or may be automatically set when used.
It is assumed that the terminal devices 1 and 2 of this embodiment have TEI management means for automatically setting the TEI according to a known procedure with the network side or notifying the network of the set TEI.

In the above configuration, when the terminal devices 1 and 2 are connected to the above-mentioned home bus and are supplied with device power, they execute known procedures with the network side to automatically set the TEI.

In the present embodiment, the terminal device 1 executes an operation unique to the present invention, and the terminal device 2 executes a known operation similar to the conventional operation. When an incoming call is received, the terminal device 1 preferentially responds and performs communication.

FIG. 2 shows the operation of the terminal device 1.
That is, the terminal device 1 constantly monitors the start and end of communication of the terminal device 2 on the line (from process 101, N of process 101 to process 102, and from process N to process 101).

In the present embodiment, after the operation of the terminal device 1 is started, the operator executes some communication operation once, such as making a call to an arbitrary destination using the terminal device 2. When the terminal device 2 starts the communication operation, it starts transmitting and receiving various signals for call control on the D channel. At this time, the terminal device 1 on the same line transmits the signal transmitted from the terminal device 2 to D
Can be received on the channel. This received signal includes
The TEI of the terminal device 2 is set. Terminal device 1
Determines the start of the communication operation of the terminal device 2 based on the D-channel received signal.

When the terminal device 2 starts the communication operation (Y in process 101), the terminal device 1 reads and stores the TEI of the terminal device 2 set in the received signal (process 103). Then, when the communication operation of the terminal device 2 ends (Y in the process 102), the terminal device 1 executes the TEI verification procedure. This TEI verification procedure includes a layer 2 UI (Unnumbered Info) with the ISDN.
ation) frame is a known procedure for transmitting and receiving various command signals.

That is, the terminal device 1 first sends a TEI verification request to the network as shown in FIG.
04). Upon receiving the TEI verification request, the network sends a TEI check request to the terminal devices 1 and 2. Terminal device 1
First responds to the TEI check request with a predetermined TEI check response using the TEI set in its own device (process 105). Then, a predetermined TEI check response is made with the TEI set in the terminal device 2 (process 106). Thereafter, the incoming call is monitored (process 107).
N loop).

The terminal device 2 also receives the TEI check request sent from the network. And the terminal device 2
Performs a predetermined TEI check response with the TEI set in the terminal device 2 before and after the check response of the terminal device 1.

Thus, the network is connected to the same TE of the terminal device 2.
I is received from the terminal device 1 and the terminal device 2, respectively. When the network receives the same TEI repeatedly,
It determines that there is an EI allocation error and sends a TEI release request. This TEI release request is 2 to ensure processing.
It is designed to be transmitted continuously. Upon receiving the TEI release request, the terminal device 2 sets the T
Release EI.

Here, it is assumed that a predetermined call setup message "SETUP" is transmitted from the network, and a call is received on the lines of the terminal devices 1 and 2. Upon detecting an incoming call (Y in process 107), the terminal device 1 immediately executes a predetermined response procedure. That is, first, a SABME frame is sent to the network,
Upon receiving the response of the UA frame from the network, the connection of the layer 2 is established. Next, the response message “CON
N "to execute the layer 3 call connection procedure.

On the other hand, the call setup message "SETU
“P” also detects the terminal device 2. In this case, the terminal device 2
Has released the TEI, so the call setup message “S
Upon receiving "ETUP", a predetermined TEI assignment procedure is executed. That is, the terminal device 2 first sends a TEI assignment request. The network sends a TEI assignment completion command to notify the terminal device 2 of the TEI to be set.
The terminal device 2 sets the notified TEI. Then, the procedure executed by the terminal device 1 is similarly executed.

In this case, the transmission timing of the response message “CONN” of the terminal device 2 is delayed by the time required for the TEI assignment procedure. Therefore, when the terminal device 2 transmits the response message “CONN”, the terminal device 1 has already completed the call connection with the other party. For this reason, the terminal device 2 sends the release completion message “RE
L COMP ”is received, and the call connection procedure is stopped.

In this way, the terminal device 1 preferentially establishes a call connection with the other party and executes a predetermined communication on the B channel (process 108). When the communication is completed, the process returns to monitoring the communication operation of another terminal (to the process 101).

As described above, in this embodiment, the terminal device 1
Receives the TEI check request from the network, responds to its own terminal TEI as usual,
Also try to respond. As a result, the network receives the same TEI from the terminal device 1 and the terminal device 2, determines that there is a TEI allocation error, and releases the TEI of the terminal device 2.

With the TEI of the terminal device 2 released,
When an incoming call is received, the terminal device 1 can respond earlier than the terminal device 2. As a result, the terminal device 1 can always communicate with priority.

The terminal device 1 constantly monitors the communication state of the terminal device 2 and, when the communication of the terminal device 2 ends,
A TEI verification request is sent to the network to make a TEI check request. Thereby, the TEI acquired by the terminal device 2 during communication is released each time, and the terminal device 1
Can give priority response.

Since the terminal device 1 reads the TEI of the terminal device 2 from the received signal of the D channel, it is not necessary to manually set the TEI of the terminal device 2 in the terminal device 1.

In the above embodiment, the terminal device 1
In order to make the network issue a TEI check request, a TEI verification request is sent.
Since the I-check request is periodically sent to the terminal device, a procedure for releasing the TEI of the terminal device 2 at the time of sending the I-check request may be executed.

Also, a case where two terminal devices are connected to one line has been described. In the case of three or more terminals, one terminal executes a check response a plurality of times at each TEI of other terminals. Then, similarly, the TEI of another terminal may be released.

Further, the plurality of terminals automatically set the TEI, respectively.
The TEI may be fixedly set.

[0037]

As described above, according to the present invention, when one terminal receives a TEI check request from the network,
As the check response, the TE set in the own terminal
I and the TEI set for the other terminal on the same line, so that the T
Since the EI is released by the network, one terminal can always respond and give priority to communication.

[Brief description of the drawings]

FIG. 1 is an apparatus configuration diagram of an ISDN terminal equipment according to an embodiment of the present invention.

FIG. 2 is an operation flowchart of one terminal device that responds with priority.

FIG. 3 is an explanatory diagram of a communication procedure between an ISDN network and each terminal device.

[Explanation of symbols]

 1, 2 terminal device 3 NT

Claims (3)

(57) [Claims] 1. A plurality of terminal devices are connected to one line of an ISDN network, and the network side sends a check request of a terminal point identifier to each terminal device, and a terminal point notified from each terminal device as a check response. If the identifiers are duplicated, an ISDN that causes each corresponding terminal device to release the termination point identifier
In the method for controlling communication between a network and a terminal, one of the plurality of terminal devices, when receiving a check request for a terminal identifier from the network, receives a check response of the terminal identifier set for the terminal itself. A communication control method between an ISDN network and a terminal, wherein the terminal performs a check response of a termination point identifier set in each of the other terminals. 2. The method according to claim 1, wherein the one terminal device sends a verification request for a termination point identifier to the ISDN network immediately after the communication operation of the other terminal device ends, and causes the network device to send the check request. The method for controlling communication between an ISDN network and a terminal according to claim 1. 3. The terminal device according to claim 1, wherein the one terminal device automatically recognizes a termination point identifier set in another terminal device by reading a received signal on a connected line. A communication control method between an ISDN network and a terminal as described in the above.