JPH0548766A - Isdn terminal device - Google Patents

Abstract

PURPOSE:To display the use state of the control channel of the basic interface of the terminal device without placing any load on an exchange. CONSTITUTION:The line use state display means 7 of the ISDN terminal device 2 monitors control information on the ISDN basic interface 4 to judge the use state of the control channel. Namely, the transmission and reception of the control information is monitored by the network control circuit of the terminal device 3 to display the use state without placing any load on the exchange 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used in ISDN terminal equipment. In particular, it relates to a line busy display means using control information of a control channel of a basic interface.

[0002]

2. Description of the Related Art In a conventional example, an ISDN terminal device sends a temporary phase call message to an ISDN exchange to
The response message from the N switch is received. ISDN
The terminal device determines the information channel in use based on the setting of the information channel in the received response message and displays it on the display device.

[0003]

In such a conventional example, since a temporary-phase call message is sent to the ISDN exchange in order to judge the use state, there is a drawback that the load of the exchange becomes large.

The present invention eliminates such drawbacks, and an object of the present invention is to provide an ISDN terminal device having means for displaying the usage status of the control channel without imposing a burden on the exchange.

[0005]

According to the present invention, there is provided a basic interface circuit connected to an ISDN exchange through a basic interface consisting of two information channels and one control channel, and a control channel of the basic interface. A network control circuit having means for receiving a call origination message, a call disconnection message, and an incoming call message addressed to the own terminal device, which are exchanged between the ISDN exchange and another ISDN terminal device, and use of the two information channels In an ISDN terminal device provided with a display circuit for displaying a status, the network control circuit is monitored to determine an information channel to which a call origination message or a call disconnection message is sent and received, and the display circuit of the display circuit according to the result of the determination It is characterized by having a central processing circuit for controlling display contents.

[0006]

The control information transmitted and received via the basic interface 13 between the ISDN terminal device 3 and the ISDN exchange 1 is received by the network control circuit 6, and this control information is analyzed by the central processing circuit 8 to be analyzed by the basic interface 13. Then, the central processing circuit 8 displays the result on the display circuit 7 so that the ISDN terminal device 2 knows the usage state of the information channel of the basic interface.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of this embodiment.
To the ISDN exchange 1 via the basic interface 13
SDN terminal devices 2 and 3 are connected. ISDN
In the terminal devices 2 and 3, the basic interface circuit 4 is connected to the communication circuit 5 via the first information channel 10 and the second information channel 11, and is connected to the network control circuit 6 via the control channel 12. The central processing circuit 8 exchanges control information with the ISDN exchange 1 via the network control circuit 6 by the program of the storage circuit 9.

The ISDN terminal device 2 of this embodiment is shown in FIG.
As shown in, ISDN is transmitted through the basic interface 13 consisting of two information channels and one control channel.
The above-mentioned IS is transmitted through the basic interface circuit 4 connected to the exchange 1 and the control channel of the basic interface 13.
A network control circuit 6 having means for receiving a call origination message, a call disconnection message, and an incoming call message addressed to the own terminal device, which are exchanged between the DN switch 1 and the other ISDN terminal device 3, and the above two information channels. Further, as a feature of the present invention, the network control circuit 6 is monitored to determine the information channel to which the call origination message or the call disconnection message is sent and received, and this determination is made. A central processing circuit 8 is provided for controlling the display contents of the display circuit 7 according to the result.

Next, the operation of this embodiment will be described. When a call is made from the ISDN terminal device 3 to the ISDN exchange 1 for communication, a call message is exchanged and the free information channel is connected. At this time, the sending and receiving of the calling message is also sent to the ISDN terminal device 2 via the basic interface 13. In the ISDN terminal device 2, the message received via the basic interface circuit 4 and the control channel 12 is analyzed by the network control circuit 6 and the central processing circuit 8 to determine whether it is a normal incoming call message. When the central processing circuit 8 determines that the message is not an incoming call message, the central processing circuit 8 executes a program by the storage circuit 9 to display the line use status and analyzes the message. The central processing circuit 8 determines whether the information channel is connected by the message and which information channel is used.
Then, the central processing circuit 8 displays the information channel in use on the display circuit 7.

When the communication of the ISDN terminal device 3 is completed, the ISDN
When the call disconnection message is exchanged with the DN exchange 1, the ISDN terminal device 2 determines whether it is a normal incoming call message as when the ISDN terminal device 3 makes a call. When the central processing circuit 8 analyzes the message and determines that the connected information channel is disconnected, the display circuit 7 stops displaying the information channel. This procedure allows the ISDN terminals 2 and 3 to display a busy information channel of the basic interface.

[0011]

As described above, the present invention is based on the ISD.
The network control circuit of the ISDN terminal device monitors the exchange of control information using the control channel in the use state of the two information channels of the basic interface of the N exchange, so that the use state is always displayed without imposing a load on the exchange. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

[Explanation of symbols]

 1 ISDN exchange 2, 3 ISDN terminal device 4 basic interface circuit 5 communication circuit 6 network control circuit 7 display circuit 8 central processing circuit 9 memory circuit 10 first information channel 11 second information channel 12 control channel 13 basic interface

Claims (1)

[Claims] 1. A basic interface circuit connected to an ISDN switch through a basic interface consisting of two information channels and one control channel, and the above-mentioned I interface via the control channel of the basic interface.
A network control circuit having means for receiving a call origination message, a call disconnection message, and an incoming call message addressed to the own terminal device, which are transmitted and received between the SDN exchange and another ISDN terminal device, and the use states of the above two information channels. In an ISDN terminal device provided with a display circuit for displaying, the network control circuit is monitored to determine the information channel to which the call origination message or the call disconnection message is transmitted and received, and the display of the display circuit is performed according to the result of the determination. An ISDN terminal device comprising a central processing circuit for controlling contents.