JPH05227213A - Fault detouring system for packet switchboard - Google Patents

Abstract

PURPOSE:To obtain a fault detouring system returning a switched line into an original line without interrupting communication even at the time of restoring a fault by setting an alternative line in a network without notifying the fault to a user in the case of the fault of a relay line during data communication in a data communication network composed of a packet switchboard and a relay line. CONSTITUTION:In the case of the fault of a relay line, it is noticed to an exchange control section 102 deciding a data communication path. Then the candiate of the alternative line is used and the control section negotiates whether or not the alternative line is switched to an opposite station. A function used for setting the loop back of data is provided on a faulty relay line control section 104 or 204 when the alternative line is decided. Then the detouring of the fault of the relay line is executed uninterruptibly without informing the user of it. Switch back is implemented in the network at the restoration of the fault.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication system in a packet switching network, and more particularly to a failure bypass system of a packet switch which forms a communication bypass when a failure occurs in a relay line.

[0002]

2. Description of the Related Art In a conventional data communication network, when a relay line fails, a terminating subscriber (hereinafter referred to as "user")
Was notified of the failure and communication was interrupted. When communication is interrupted, the user restarts the communication by selecting a new route by calling again.

[0003]

In the conventional data communication network, there is a problem that the communication requested by the user needs to confirm the normal end of the communication, which is inefficient. In addition, in services that provide data using data communication networks,
There is a demand for quick response from the terminal device,
There was a problem that the redo of the operation due to the line failure deteriorates the reliability. Further, if the public network is used for calling again the fault, even if the fault is recovered immediately, the route of the public network is used until the requested communication is completed, which is uneconomical. An object of the present invention is to solve the above problems, and to provide a fault circumvention method of a packet switch that does not show a fault to a user even if a fault occurs in a relay line and continues communication without interruption. is there.

[0004]

In order to achieve the above-mentioned object, a failure bypass method for a packet switch according to the present invention accommodates a relay control line and a switching control unit that determines a route through which data passes during data communication. In a dedicated data communication network constructed with a packet switch and a leased line having a relay line control unit capable of detecting a failure at the time of a fault, the relay line control unit is provided to the switching control unit when the relay line between the packet switches has a fault. Upon notification of the failure, the switching control unit gives a restriction instruction for data transfer to the trunk line control unit that has detected the failure and the control unit that is in the process of switching, determines an alternative trunk line during the restriction instruction, and uses this alternative line. If an alternative trunk line is available as a result of the negotiation by negotiating with the partner packet switch, the alternative trunk line controller is used as the trunk line controller that detected the failure. Notifications are configured to wrap the communication data to an alternate transit trunk control unit from the relay circuit control unit that detected the fault by. In the above-mentioned configuration, the control unit during the exchange operation may be a terminal control unit that is connected to a terminal device via a terminal line and controls the terminal device.

[0005]

According to the above construction, even if a failure occurs in the relay line during communication, a detour of the line can be formed and communication can be continued without notifying the user that the failure has occurred.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a packet switching network including a packet switching device and a relay line using a failure bypass method according to the present invention. The packet switches 10 and 20 are composed of internal transfer buses 101 and 201, switching control units 102 and 202, terminal control units 103 and 203, and trunk line control units 104, 204, 105 and 205, respectively. The packet switch 10 is connected to the terminal 11 via the terminal line 12, and the packet switch 20 is connected to the terminal 21 via the terminal line 22, respectively.
0s are connected by the relay line 3. Also, an alternative line 4 is provided.

Here, the side requesting the data communication is called a calling terminal and a calling packet switch, and the receiving side is called a called terminal and a called packet switch. FIG. 2 is a block diagram showing a data communication path when the packet switching network of FIG. 1 is normal. When the calling terminal 11 requests data communication in a normal state, the switching control unit 102 of the calling packet switch 10 determines a route, selects the trunk line 3, and selects the called terminal 2
Communicate with 1.

When the relay line 3 fails during the data communication and the continuation of the data communication becomes impossible, the relay line control units 104 and 204 inform the exchange control units 102 and 202 of their own stations of the fault notification signal 13 and 23 is transmitted.
The switching control units 102 and 202 send the data transfer restriction signals 14 and 24 to the faulty relay line control unit and the terminal control units 103 and 203 of the own station in the switching operation to prevent data from flowing to the faulty line. In the meantime, an alternative trunk line is determined. The method is the exchange control unit 102 on the calling side.
Sends an alternative permission negotiation signal 51 to the alternative line 4,
The exchange control unit 202 on the called side confirms whether or not it can be used as a substitute for a failure. If possible, the exchange control unit 202 on the called side returns an alternative permission notification signal 52.

When the alternative line is determined, the switching control unit 102
And 202 are the trunk line control units 104 and 20 of the failure.
4 is notified of the alternative line determination signals 15 and 25, and the data transfer regulation instructed to the terminal control units 103 and 203 is released. As a result, the trunk line control units 104 and 20
4 sets the return of data, the data transmitted from the calling terminal 11 is returned by the relay line control unit 104, and the communication is continued via the relay line control unit 105 and the alternative line 4. FIG. 3 shows a detour of the data communication path at the time of failure of the relay line.

When the trunk line control unit 104 detects a trunk line fault, it negotiates with the partner packet switch 20 by a procedure similar to the above-mentioned alternative line switching procedure. That is, the switching control unit 102 is notified, and the switching control unit 102 uses the alternative line 4 to negotiate with the switching control unit 202 on the called side whether the line can be switched back. If possible, the relay line control units 104 and 204 are notified of this, and the loopback state is released to switch back to the original communication path.

[0011]

As described above, according to the present invention,
When a failure occurs in the trunk line, the relay line control detects a failure in the packet switch and transmits the data to the alternate line. Therefore, the user can continue the communication without interrupting the trouble and without interrupting the communication. Also, since it is possible to switch back to the original line immediately after the failure of the relay line is restored,
The effect is that the usage fee for the public network is minimal and economical.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a failure bypass method of a packet switch according to the present invention.

FIG. 2 is a block diagram showing a data communication path in a normal state of the packet switch of FIG.

FIG. 3 is a block diagram showing a data communication path at the time of a trunk line failure of the packet switch of FIG.

[Explanation of symbols]

 3 ... Trunk line 4 ... Alternate line 10 ... Calling packet switch 11 ... Calling terminal 12 ... Calling terminal connection line 13, 23 ... Trunk line failure notification signal 14, 24 ... Data transfer restriction instruction signal 15, 25 ... Alternate line Decision notification signal 20 ... Called packet switch 21 ... Called terminal 22 ... Called terminal connection line 51 ... Alternative permission negotiation signal 52 ... Alternative permission notification signal 101,201 ... Data transfer bus 102,202 ... Exchange control unit 103,203 ... Terminal control unit 104, 105, 204, 205 ... Trunk line control unit

Claims (2)

[Claims] 1. A dedicated packet switch and dedicated line constructed with a switching control unit for determining a route through which data passes during data communication, and a relay line control unit for accommodating a relay line and capable of detecting a fault when a fault occurs in the relay line. In the above data communication network, when the relay line control unit fails in the relay line between the packet switches, the relay control unit notifies the switching control unit of the fault, and the switching control unit is in the process of exchanging operation with the relay line control unit which detected the fault Instructing the control section of the control of data transfer, determining an alternative trunk line during the restriction instruction, negotiating with the partner packet switcher whether this alternative line can be used, and as a result of the negotiation, an alternative trunk line can be used. In this case, by notifying the alternative trunk line controller to the trunk line controller that has detected the failure, the trunk line controller that has detected the failure causes the alternative trunk line controller to Failover method of packet switch, characterized by being configured to wrap signal data. 2. The fault bypass system for a packet switch according to claim 1, wherein the control unit during the switching operation is a terminal control unit which is connected to a terminal device by a terminal line and controls the terminal device.