JPH02235465A - Call interruption device - Google Patents

Abstract

PURPOSE:To surely interrupt a call by outputting a terminal interrupt command signal in place of a call interruption command when a fault is detected or disconnecting a terminal equipment physically from the network. CONSTITUTION:Upon the detection of hook-on, a processor 10 outputs a call interruption command to an ISDN 3 through a layer 2.hardware 5 and a layer 1.hardware 6. On the other hand, when a fault detection section 14 detects a fault, a counter circuit 15 starts the count. After a prescribed time elapses, when the counter circuit 15 expires, an output of a switching circuit 12 is switched. Then an interruption command signal outputted from an interruption command signal output section 13 is outputted to the ISDN 3 via the switching circuit 12 and a driver receiver 7. The ISDN 3 receives the signal to execute the interruption of a terminal equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is directed to an integrated service digital network (ISDN)
It relates to a call disconnection device installed in a terminal device connected to

(Prior Art) In order to achieve international standardization of data communications, various standardization work is being carried out at CCITT.

ISDN is one of the communication networks systematized by this CCITT recommendation. This communication network is a network that can connect telephones, facsimiles, and computer terminals, and provides a wide range of comprehensive services. ISDN is a versatile user/network interface that includes packet switching and high-speed services, providing digital links that support telephone and non-telephone services.

FIG. 2 shows a block diagram of a conventional terminal device connected to ISDN.

As shown in the figure, a terminal device 1 is connected to a device 2 such as a telephone or a facsimile device, which is connected to an ISDN 3. The terminal device 1 includes a processor 4, layer 2 hardware 5, layer I hardware 6, and a driver receiver 7. In addition, the terminal device 1
It is connected to ISDN3 via reference point S point 8 in the CITT recommendations.

The ISDN user access specifications are stipulated to be described in a layered protocol.

That is, the layer 1 hardware 6 of the terminal device 1 in the figure is I
It configures the connection interface with the 4-wire metallic wire connected to SDN3, and complies with the OSI (open system interface) in the CCITT ISO standard.
connection) Corresponds to the physical layer of the 7 layers of the reference model. Further, layer 2/hardware 5 is an interface that performs frame multiplex transmission of signal packets, etc., and corresponds to a data link layer.

Furthermore, the processor 4 has an interface function that processes the network layer and above, which controls line switching, reception procedures, disconnection procedures, and the like.

When the terminal device 1 described above performs call setup, call disconnection, etc. with the ISDN 3, it exchanges a fixed format and message with the ISDN. The message output from the terminal device 1 to the ISDN 3 is called a command, and the message output from the ISDN 3 to the terminal device 1 is called a response.

If the device 2 in the figure is, for example, a telephone, communication is started by off-hook and terminated by off-hook. At the end of communication, the call is disconnected according to the following procedure.

FIG. 3 is an explanatory diagram of a call disconnection operation of a conventional terminal device.

First, when the processor 4 detects on-hook by the device 2 shown in FIG. 2, the processor 4 detects layer 1. A disconnection request is issued to layer 2 hardware 5.6.

Corresponding to this, layer 1, layer 2, hardware 5.
6 outputs a DISC command (call disconnection command) to ISDN 3. ISDN3 uses the DISC command.
When receiving this, it executes call disconnection processing and outputs a UA response to the terminal. The layer 1 and layer 2 hardware 5.6 receives this UA response and notifies the processor 4 of completion of disconnection.

The above process completes the call disconnection.

(Problems to be Solved by the Invention) In the conventional terminal device as shown in FIG. 2, for example, the device 2 may not be able to supply the on-footer signal to the processor 4 for some reason. Also, even if processor 4 detects on-hook, layer 2? There are cases where it is not possible to output a disconnection request to the hardware 5. Further, if there is some kind of failure in layer 2/hardware 5, layer 1/hardware 6, etc., it becomes impossible to output a DISC command (hereinafter referred to as a call disconnection command) to ISDN 3.

If this situation occurs, the call cannot be disconnected even if the actual communication ends, and communication fees will continue to be charged. This places a heavy burden on the user and also makes it impossible to quickly recover from failures.

The present invention has been made with attention to the above points, and even if a failure occurs in the terminal device or equipment connected to it, the
The purpose of this invention is to provide a call disconnection device that can reliably disconnect a call. (Means for Solving the Problems) A call disconnection device of the present invention is an integrated service digital network (I
In a terminal connected to SONY, when a failure occurs in which the terminal device does not output a call disconnection command that should be output to the network, a failure detection unit that detects the failure, and when the failure is detected, The present invention is characterized by comprising a disconnection instruction signal output unit that generates a disconnection instruction signal for disconnecting the terminal from the network in place of the call disconnection command, and outputs the generated disconnection instruction signal to the network.

Further, the call disconnection device of the present invention can be used in a terminal device connected to an integrated services digital network (ISDN), when a failure occurs in which a call disconnection command that the terminal device should output to the network is not output. The present invention is characterized by comprising a failure detection unit that detects the failure, and a disconnection unit that physically disconnects the terminal from the network when the failure is detected.

(Operation) The device of the present invention described above operates to detect a failure and automatically disconnect the terminal from the network when a failure occurs. The disconnection involves actively outputting a disconnection instruction signal, and
There is a method of physically disconnecting the terminal device itself from the network. As a result, the terminal device is brought into a state where it is not connected to the network, and is immediately put into a state where it can be repaired, inspected, etc.

In addition, if the failure is temporary and can be recovered within a short time,
It is preferable to output a call disconnection command and normally disconnect the call. For this purpose, a timing circuit is provided that measures a certain amount of time from when a fault is detected until the network is disconnected. Therefore, if the fault is recovered within this time, the call can be normally disconnected by outputting the call disconnection command.

Further, when the fault is recovered, the operation of the timer circuit is stopped by the timer stop circuit. As a result, when a failure occurs again, the timer circuit immediately starts timekeeping from the initial state.

(Example) Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 is a block diagram showing an embodiment of a call disconnection device of the present invention.

The device shown in the figure is similar to the conventional device explained in FIG.
It is connected to ISDN 3 via S point 8.

This device has a configuration in which a processor 1o, layer 2 hardware 5, layer 1 hardware 6, switching circuit 12, and driver receiver 7 are connected in this order.

Further, the switching circuit 12 is configured to receive the output of the disconnection instruction signal output section 13 in addition to the output of the layer 1/hardware 6. In addition to this, the failure detection unit 14
and a clock circuit 15 are provided.

The fault detection unit l4 is configured to receive an alarm signal indicating the occurrence of a fault in a device (not shown) or each part of the terminal device connected to this terminal device.

Here, it is assumed that there are five types of alarm signals, for example, alarm 1 to alarm 5.
6 and is output to the processor 1o, while being connected to the OR gate 17.

Further, an on-hook detection signal is input to the processor IO, and the processor IO is wired so that this on-hook detection signal is input to the OR gate 17 of the failure detection section 14. The output of the agate 17 of the fault detection section 14 is connected to be input to the clock circuit 15.

The timekeeping circuit 15 is composed of a counter and the like, and is configured to start timekeeping in response to a signal input from the failure detection unit 14, and to stop timekeeping in response to a signal inputted from a timekeeping stop circuit 1l provided in the processor 1o. There is. When the counter of the timer circuit 15 counts a certain value, that is, when the time is up, an output switching signal is output to the switching circuit 12 using a carry signal of the counter or the like. The switching circuit l2 switches the layer l by this output switching signal.
- This circuit is configured to send either a signal input from the hardware 6 or a signal input from the disconnection instruction signal output section 13 to the driver receiver 7. The disconnection instruction signal output unit 13 connects this terminal to ISDN3.
This is a circuit that generates a signal for disconnecting from the CCIT
T. According to the J43'0 recommendation, INF from the terminal
When the OO signal is output, the ISDN performs processing to disconnect the terminal from the network. When communication ends normally and the call is disconnected by the above-described call disconnection command, the terminal device is under the control of the ISDN and communication can be resumed at any time thereafter. However, disconnection means temporarily removing a terminal device from network control in order to recover from a failure, etc., and in order to resume communication, procedures such as opening a new terminal device must be performed. INFO
The O signal is thus a signal that has a different meaning from the call disconnection command. The disconnection instruction signal output section l3 is provided with a circuit for generating such a signal, for example.

Next, the general operation of the apparatus of the present invention having the above configuration will be explained.

In a normal case, when the processor 10 detects a power hook, the processor 10 sends the ISD through the layer 2 hardware 5 and the layer 1 hardware 6 in the manner described above in FIG.
Outputs a call disconnection command to N3. The call is then disconnected in the manner shown in FIG.

On the other hand, if some kind of failure occurs, the failure detection section 14 detects the failure and causes the timekeeping circuit 15 to start measuring time. The clock circuit 15 is for securing a waiting time to give priority to the process of outputting a call disconnection command from the layer 2 and layer 1 hardware.If the time is up after a certain period of time, the switching circuit 15 12 outputs are switched.

As a result, the disconnection instruction signal output from the disconnection instruction signal output section 13 is transmitted to the switching circuit 12 and the driver receiver 7.
It is output to ISDN3 via.

When ISDN 3 receives this signal, it performs a disconnection operation for this terminal device.

As described above, the call disconnection device of the present invention allows IS
Controls the substantial disconnection of the terminal device from DN3. Therefore, the disconnection instruction signal does not necessarily have to be the INFO O signal. In other words, if the ISDN 3 cannot recognize a signal, the ISDN 3 will automatically disconnect the terminal, so it is sufficient if a signal of such nature is output.Also, it is sufficient to output a signal of such nature. This purpose can also be achieved by so-called physical decoupling.

FIG. 4 is a block diagram of a modification of the call disconnection device of the present invention implementing such a principle.

The device shown in the figure is layer 1/hardware 6 of the device shown in FIG.
This is a configuration in which the circuit between ISDN3 and ISDN3 is replaced.

That is, a driver receiver 7 is connected to the layer 1 hardware 6, and a disconnection section 18 is provided on the output side thereof. The disconnection unit 18 outputs the output from the driver receiver 7 toward the ISDN 3, and disconnects the driver receiver 7 and the ISDN 3 when an output switching signal is input from the clock circuit 15. That is, the disconnection section 18 is composed of a switch or the like having a configuration in which the input terminal B of the switching circuit 120 shown in FIG. 1 is open.

FIG. 5 shows a specific wiring diagram of the switching circuit 12 shown in FIG. 1.

A terminal device is connected to ISDN3 via four metallic cables. Therefore, in the figure, the layer I/hardware 6 is connected to the terminal A of the switching circuit 12, and the disconnection instruction signal output section 13 is outputted to the terminal B.
They are connected by a book connection. Furthermore, four outputs of the switching circuit 12 are connected to the S point 8 of the ISDNS.

The switching circuit 12 is composed of four switches SW1 to SW4, and is further provided with a solenoid L for switching these switches simultaneously.

This solenoid L is excited by the output of the clock circuit 15.

Each switch SW1 to SW4 is in a normal state,
Terminals a1 to a4 connected to layer 1/hardware 6
and ISDN3 are connected. Then, when the output of the clock circuit 15 becomes high level, the solenoid L
is excited, and the switches SWI to SW4 are simultaneously switched to the terminal blNb4 side and connected to rsDN3.

Incidentally, the disconnection section 18 shown in FIG. 4 may be one that is not connected to the terminals bl to b4.

FIG. 6 shows a specific operational flowchart of the apparatus of the present invention.

As shown in the figure, the device of the present invention shifts to an operation such as disconnection when switching from an off-hook state to an on-hook state (steps Sl, S2) and from a state in which an alarm is generated (step S3).

That is, in FIG. 1, when an on-hook condition or failure is detected, this is detected by the processor IO;
The clock circuit 1 through the OR gate 17 of the failure detection unit l4
5 is started (step S4). processor 1
0 executes a process of outputting a call disconnection command through layer 2/hardware 5 and layer 1/hardware 6 when on-hook is detected.

Here, it is determined whether the processor etc. are normal (step S5). Brosetsu. If the service etc. are normal, Di
sc command is sent (step S6) IS
A UA response is received from DN3. It is determined whether a UA response has been received (step S7).
If this is normally received, a clock stop signal is output from the clock stop circuit 11 of the processor 10 to the clock circuit 15, and the counter that is currently counting is cleared to 0 (step S8). As a result, the clock circuit 15 returns to its initial state, and the call disconnection is completed.

On the other hand, even if the processor 10 detects the on-footer, if the processor 10 etc. do not operate normally, the clock circuit 15
automatically continues counting the predetermined time. Therefore, when the time-up is detected (step S9), the output of the switching circuit 12 is switched, and the disconnection instruction signal output section 13
An INFO O signal is sent from the ISDN 3 to the ISDN 3 (step SIO). As a result, the ISDN 3 disconnects the terminal (step S11).

FIG. 7 shows another operational explanatory diagram of the apparatus of the present invention.

When an alarm signal is input to the failure detection unit 14 in FIG. 1 due to a failure occurring in a device connected to the terminal device or a main part of the terminal device, the signal is input to the processor 10, and the failure detection unit ? The signal is input to the clock circuit 15 through the OR gate 17 of No. 4, and the clock is started as shown in FIG. When the timer expires, a disconnection operation is performed in the same manner as in the case of the hook described above with reference to FIG. Meanwhile, processor 10 determines whether the failure requires disconnection of the terminal device. For example, if the failure is such that it can be automatically recovered in a relatively short time, it is not necessary to disconnect the terminal device, and therefore the timekeeping circuit 15 is instructed to stop timekeeping through the timekeeping stop circuit 11. After recovery, the original operation will continue.

Similarly, when on-hook or a failure is detected, the timer automatically starts counting, but no disconnection operation is performed if it is possible to output a call disconnection command.

That is, the apparatus of the embodiment shown in FIG.
When the time is up, the separation operation will begin.

The present invention is not limited to the above embodiments.

The failure detection unit l4 detects a state in which a call disconnection command cannot be output.
If the switching circuit can be directly detected, the disconnection operation may be performed by directly operating the switching circuit without particularly providing a timing circuit. Furthermore, if the clock circuit is reset by outputting a call disconnection command, etc., it is not necessarily necessary to provide the clock stop circuit 11 on the processor 10 side.

(Effects of the Invention) According to the call disconnection device of the present invention described above, even if a failure occurs in which the terminal device cannot output a call disconnection command to the network, a disconnection instruction signal is generated and output instead. Therefore, it is possible to solve the conventional problem of continuing billing after a failure occurs. Furthermore, the same effect can be obtained by physically separating the terminal from the network. Furthermore, by setting the operation time from detection of a fault to network disconnection to a certain amount of time, you can secure preparation time for outputting the call disconnection command, secure time for failure recovery, and avoid unnecessary disconnections. Further, if the time measurement is stopped upon detection of recovery from a failure, the disconnection operation can be smoothly stopped.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a call disconnection device of the present invention, FIG. 2 is a block diagram showing an example of a conventional terminal device, FIG. 3 is an explanatory diagram of call disconnection operation of a conventional terminal device, and FIG. 4 is a block diagram of a modified example of the call disconnection device of the present invention, FIG. 5 is a wiring diagram of the switching circuit of the device of the present invention, FIG. 6 is an operation flowchart of the device of the present invention, and FIG. 7 is a diagram of the device of the present invention. It is another operation explanatory diagram of. 3...ISDN, 5...Layer 2 hardware, 6...Layer 1 hardware, 7...Driver receiver, 1o...Processor, l
1... Timing stop circuit, 12... Switching circuit, 13...
- Disconnection instruction signal output section, 14...Fault detection section, l5...Time measurement circuit. Fig. 3 is a wiring diagram of a switching circuit; Fig. 5 is an explanatory diagram of another operation of the device of the present invention; Fig. 7 is a flow chart of the operation of the device of the present invention;

Claims (1)

[Claims] 1. In a terminal connected to an integrated services digital network (ISDN), when a failure occurs in which a call disconnection command that the terminal device should output to the network is not output, the failure is detected. a failure detection unit; and a disconnection instruction signal output unit that generates a disconnection instruction signal for disconnecting the terminal from the network instead of the call disconnection command when the failure is detected, and outputs the generated disconnection instruction signal to the network. A call disconnection device comprising: 2. In a terminal device connected to an integrated services digital network (ISDN), when a fault occurs in which a call disconnection command that the terminal device should output to the network is not output, a fault detection unit that detects the fault; A call disconnection device comprising: a disconnection unit that physically disconnects the terminal from the network when the failure is detected. 3. A timing circuit that sets an operating time from the detection of the fault to the disconnection of the network, starts timing at the same time as the fault is detected, and starts disconnecting the network when the operating time is reached. The call disconnection device according to claim 1 or claim 2, characterized in that: 4. The call disconnection device according to claim 1 or 2, further comprising a timekeeping stop circuit that stops the timekeeping when recovery from the failure is detected within the operating time after the start of the timekeeping. .