JPH03229553A - Isdn system - Google Patents

Abstract

PURPOSE:To avoid wasteful receiving processing at ISDN terminal equipment at the time of the incoming of a call transferred in the form of broadcasting by making only the ISDN terminal equipment to which a TEI value is assigned continue terminating processing, and returning the other ISDN terminal equipment concerned to which the TEI value is not assigned to a receive preparing state. CONSTITUTION:UI frame information transmitted from an ISDN is transferred in the form of the broadcasting to every ISDN terminal equipment 3 to 5 through a network terminating set 2. Each ISDN terminal equipment 3 to 5 checks the contents of a UI frame, and checks whether or not a reference number is the same as the assigned TEI value, and when it is the same, it continues the terminating processing, and when it is not the same, it returns to a receive waiting state without executing releasing sequence. Accordingly, even in the case the incoming call is transferred at a time in the form of the broadcasting to plural ISDN terminal equipment 3 to 5 connected on bus wiring, the wasteful communication sequence at arrival of the call at the ISDN terminal equipment 3 to 5 like in the past can be excluded, and an unnecessary communication record does not remain either.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ISDN system, and more particularly to an ISDN system that improves the efficiency of incoming call processing in a plurality of ISDN terminal devices connected on a bus.

(Prior art) Recently, ISDN (Integrated Service Digital Network) has been implemented on a trial basis as a communication network that meets the communication needs of realizing a highly information-oriented society.
SDN terminal equipment has also been developed and put into practical use. ISD
N and ISDN terminal devices are connected via a network termination device to form an ISDN system, and a plurality of ISDN terminal devices can be connected to one termination device. There are two types of wiring connections between this network termination equipment and ISDN terminal equipment: star wiring and lotus wiring. ISDN terminal equipment can be freely connected to either wiring type by being equipped with an ISDN-specified socket. It is now possible to do this.

In addition, when multiple ISDN terminal devices are connected by bus wiring, communication messages sent from the ISDN are transferred to each ISDN terminal device in broadcast format, and when a call arrives, it is sent to the first ISDN terminal device on the bus. Communication rights are granted to those who respond. At this time, the ISDN terminal device for which communication rights have not been obtained has failed in call connection, so it executes a call release sequence and leaves a communication error report.

(Problem to be solved by the invention) However, such a conventional lotus wiring type ISD
In the N system, when an incoming call is transferred from the ISDN to multiple ISDN terminal devices simultaneously in a broadcast format, the ISDN terminal device that cannot obtain communication rights executes a call release sequence and leaves a communication error report. As a result, there was a problem in that not only users of ISDN terminal devices who could not obtain communication rights were forced to perform unnecessary communication processing, but also unnecessary communication records were left behind.

(Object of the Invention) Therefore, the invention according to claim 1 provides an interface to which a TEI value is assigned using the TEI assignment procedure in ISDN communication.
Only the SDN terminal device continues incoming call processing, and the other ISDN terminal devices to which no TEI value has been assigned return to the receiving ready state, thereby reducing wasted time on the ISDN terminal device when receiving calls transferred in broadcast format. IS by avoiding reception processing and leaving unnecessary communication records.
The purpose is to improve the operational efficiency when receiving calls in a DN system.

Further, the invention according to claim 2 provides that each TSDN terminal device executes the incoming call processing based on the TEI allocation procedure in the call control procedure in the TSDN communication control procedure, thereby causing unnecessary waste to the user using the ISDN terminal device. The aim is to improve the usability of the ISDN system by eliminating the need for forced reception processing.

(Structure of the invention) In order to achieve the above object, the invention according to claim 1
When a plurality of ISDN terminal devices are connected to a DN on a bus via a network termination device, and each ISDN terminal device uses the ISDN, 1. When the reference number sent from each ISDN terminal device to TSDN by the TE assignment procedure of the TSDN communication control procedure and the TEI value assigned by ISDN according to the reference number match, the ISDN terminal device with the matching TEI value is the ISDN terminal device. ISDN to obtain the right to use
In the communication method, from the ISDN to the plurality of ISDs.
When an incoming call signal is simultaneously transferred to N terminal devices in broadcast format, each ISDN terminal device and the IS
The assignment status of the TEI value based on the TEI assignment procedure performed between DNs in the broadcast format is monitored for each ISDN terminal device, and the ISDN terminal device with which the TEI value matches continues its own incoming call processing and The invention according to claim 2 is characterized in that the other ISDN terminal devices whose TEI values do not match terminate their own incoming call processing and return to a reception preparation state. In the system, each of the ISDN terminal devices
This system is characterized in that the incoming call processing based on the allocation procedure is executed in the call control procedure in the TSDN communication control procedure.

1 to 3 are diagrams showing an embodiment of the invention according to claims 1 and 2. FIG.

FIG. 1 is a diagram showing an ISDN system 1.
System 1 is a network terminal unit (DSU: Digit).
ISDN terminal devices 3 to 5 having the same ISDN communication function are connected to the service unit 2 by bus wiring. Further, the network termination device 2 is connected to an ISDN (not shown).

The network terminal device 2 sends and receives data related to ISDN communication between the ISDN terminal devices 3 to 5 and the ISDN.
Data sent from N is sent to each ISDN via bus wiring.
It is transferred to the terminal devices 3 to 5 in broadcast format.

Each of the ISDN terminal devices 3 to 5 has an ISDN communication control function, and executes an incoming call process, which will be described later, according to a TEI (termination point identifier) assignment procedure of a call control procedure.

Next, the effect will be explained.

In this embodiment, the TE in the call control procedure of ISDN communication is
The feature is that the ISDN terminal devices 3 to 5 use the I allocation procedure to determine whether to continue or interrupt the incoming call process depending on whether the TEI value assignment is correct or not during the incoming call process.

First, the TE executed in the ISDN communication call control procedure
The I allocation procedure will be explained.

In the ISDN basic interface, a TEI (termination point identifier) assignment procedure is provided in order to guarantee the portability of ISDN terminal equipment so that one ISDN terminal equipment can be used anywhere.

That is, the TEI value used by the ISDN terminal device is
Rather than registering with the SDN, a TEI assignment procedure is performed to allocate a TEI value when the need arises or to check whether a particular TEI value is in use by another ISDN terminal. ing.

Specifically, when using the ISDN, the ISDN terminal devices 3 to 5 connected to the bus shown in FIG. A request is made to allocate a TEI value, and the ISDN manages the TEI value allocation status and, if allocation is possible, sends a TEI allocation completion message and reference number to the ISDN terminal device that made the allocation request. On the other hand, if the same TEI value as the reference number has already been assigned, ISDN cannot allocate a TEI value, so ISDN sends a TEI assignment refusal message to ISDN.
It is sent to terminal devices 3 to 5.

Furthermore, in the TER allocation procedure, the ISDN side manages the TEI value allocation status, and checks the TEI values allocated to ISDN terminal equipment to prevent double allocation of TEI values. .

Next, the incoming call processing in the ISDN terminal devices 3 to 5 will be explained based on the above TEI allocation procedure with reference to the flowchart shown in FIG. 2 and the communication sequence diagram shown in FIG.

Now, suppose that each of the TSDN terminal devices 3 to 5 simultaneously receives a call from the ISDN via the network termination device 2 in a broadcast format (step PL).The ISDN terminal devices 3 to 5 each perform ISDN communication control in response to the incoming call. According to the TEI assignment procedure in the call control procedure of the function, a reference number generated by a random number is inserted into the ■ field of a UI (unnumbered information) frame and transmitted, requesting the ISDN to assign a TEI value (Step P2 ).

In response to this TEI value allocation request, the ISDN checks the TEI value allocation status and, if there is an unallocated TEI value, sends that TEI value along with the transmitted reference number to the user.
The frame is transmitted to the ISDN terminal devices 3 to 5 (see FIG. 3). Further, if there is no TEI value to be allocated, the ISDN transmits a TEI value allocation refusal to the UI frame ISDN terminal devices 3 to 5 (see FIG. 3).

The Ul frame information transmitted from the ISDN is transferred in broadcast format to each ISDN terminal device 3 to 5 via the network termination device 2.

Each ISDN terminal device 3 to 5 checks the contents of the UI frame in step P4. P5) When the TEI value assignment is completed, it is checked whether the reference number transmitted in step P1 and the assigned TEI value are the same (step P6). When the reference number and the TEI value are the same, the incoming call processing is continued, and when they are not the same, the incoming call processing returns to the reception waiting state without performing the release sequence.

On the other hand, when the TEI value assignment is rejected, the call processing returns to the reception waiting state without performing the release sequence.

Therefore, even if an incoming call is transferred simultaneously in broadcast format to a plurality of ISDN terminal devices 3 to 5 connected on the bus wiring, each ISDN terminal device 3 to 5 receives a T.
The allocation status of the EI value is checked to determine whether or not to continue incoming call processing, and the ISD that has not been assigned the TEI value and has not been able to obtain the right to use the ISDN.
Since the N terminal devices 3 to 5 are returned to the reception waiting state without performing a release sequence, it is possible to eliminate unnecessary communication sequences when receiving a call at the ISDN terminal devices 3 to 5 as in the past, and unnecessary communication records. There's nothing left. In addition, since the above-mentioned incoming call processing is performed within the ISDN communication call control procedure (ISDN D channel protocol) for each ISDN terminal device 3 to 5, users using the ISDN terminal devices 3 to 5 are forced to perform unnecessary reception processing. TS I ran out of things to do.
The convenience of the DN system is improved.

(Effect) According to the invention described in claim 1, T in ISDN communication
EIII Is assigned a TEI value using this procedure
Only the SDN terminal equipment continues incoming call processing and the relevant TE
Since the ISDN terminal device to which no I value has been assigned returns to the receiving ready state, it is possible to avoid unnecessary reception processing at the ISDN terminal device when receiving a call transferred in broadcast format, and to avoid unnecessary communication. Don't leave any records
It is possible to improve the operational efficiency when receiving a call in an ISDN system.

Further, according to the invention as claimed in claim 2, since each ISDN terminal device executes the incoming call processing based on the TEI assignment procedure as a process within the call control procedure in the ISDN communication control procedure, the ISDN terminal device is used. It is possible to avoid forcing the user to perform unnecessary reception processing, and the rsDN
System usability can be improved.

[Brief explanation of drawings]

1 to 3 are diagrams showing an embodiment of an ISDN system according to the invention as claimed in claim 1 and claim 2,
FIG. 1 is a configuration diagram thereof, FIG. 2 is a flowchart showing a program for incoming call processing, and FIG. 3 is a diagram showing a communication sequence in the TEI assignment procedure. ■...ISDN system, 2...Network termination device, 3.4.5...1sDN terminal device.

Claims (2)

[Claims] (1) When a plurality of ISDN terminal devices are connected to an ISDN on a bus via a network termination device, and each ISDN terminal device uses the ISDN,
ISDN according to the TEI assignment procedure of the SDN communication control procedure.
In an ISDN communication system, when the reference number transmitted to the ISDN matches the TEI value assigned by the ISDN according to the reference number, the ISDN terminal device with the matching TEI value obtains the right to use the ISDN. When an incoming call signal is simultaneously transferred to an ISDN terminal device in a broadcast format, the TEI value based on the TEI assignment procedure performed in the broadcast format between each ISDN terminal device and the ISDN in response to the incoming call signal. The allocation status of each ISDN terminal device is monitored for each ISDN terminal device, and the ISDN terminal device whose TEI value matches continues its own incoming call processing, and the other ISDN terminal device whose TEI value does not match continues its own incoming call processing. An ISDN system characterized in that the ISDN system is configured to return to a receiving preparation state upon termination. (2) In the ISDN system according to claim 1,
The IS characterized in that each of the ISDN terminal devices executes incoming call processing based on the TEI assignment procedure as a process within a call control procedure in the ISDN communication control procedure.
DN system.