JPH0344243A - Channel system changeover control system - Google Patents

Abstract

PURPOSE:To attain changeover to an optimum standby system by inserting a monitor cell to an incoming line at a changeover to a standby system and Selecting the standby system when a coincident signal of the monitor cells extracted from both the active system and the standby system is detected. CONSTITUTION:The system is provided with a distribution line 3 distributing an input cell of an incoming line to a channel for the active and standby system, an insertion circuit 5 inserting a monitor cell for switching control to the incoming line, extraction circuits 20, 21 extracting the monitor cell from the outputs of both the systems and a changeover circuit 4 selecting one of outputs of both the systems as an output of the active system and connecting it to an outgoing line. Then when the standby system is to be selected, a monitor cell is inserted to the incoming line, and the system is selected to the standby system after the coincidence signal of monitor cells extracted from both the active and standby systems is detected. The system is selected to the standby system by using the coincidence signal of the monitor cells extracted from both the active and standby systems in this way to attain optimum system changeover.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a communication line switching control method for a digital switching system.

[Conventional technology]

The communication paths of conventional digital switching systems are of the synchronous transfer mode (8TM) system, in which all calls are assigned time slots within a synchronized frame, and calls are exchanged synchronously. Exchange processing is in progress. Therefore, when switching to a backup communication path due to periodic maintenance or the like, it was sufficient to simply switch in accordance with the synchronization signal.

[Problem to be solved by the invention]

The above-mentioned conventional 8TM switch network channel system switching control method cannot be used for the call path of an asynchronous transfer mode (ATM) switch network that asynchronously passes calls divided into short blocks (cells). In addition, the ATM system requires high-speed operation of 150 Mb/s class, has buffers to avoid collisions with other cells due to self-routing within the switch, has variations in parts, Because it is difficult to make the line lengths, etc. of The disadvantage is that it is not possible to switch to the system.

[Means to solve the problem]

The communication path system switching control method of the present invention includes: a distribution circuit that distributes input cells of an incoming line to a working system and a protection system; an insertion circuit that inserts a monitor cell for switching control into the incoming line;
In an asynchronous transfer mode switch network having a working system and a standby system, which is equipped with an extraction circuit that extracts a monitor cell on the output side of both systems, and a switching circuit that connects one of the outputs of both systems to the outgoing line as the working system, When switching to the protection system, the monitor cell is inserted into the incoming line, and when a matching signal of the monitor cells extracted from both the working system and the protection system is detected, switching to the protection system is performed.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

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

First, let us consider the case where the 0-system ATM switch and the Q communication path (hereinafter referred to as 5P) 10 are currently in use. Cells A and H that came in from the incoming line
, C~ are sent to 8PIO by the input cell distribution circuit (hereinafter referred to as D8'l') 3, and cells A, B, C~ are sent to 5PII of the l system.
Copy cell person 1. Bl, C1~ can be sent. Switching circuit (
Since 5W) 4 is connected to the 5PIO side as shown by the broken line, cells that have passed through the 5PIO are sent to the outgoing line.

Here, for regular maintenance etc., the communication path control circuit (hereinafter referred to as 8PC)
) 8 outputs a switching request signal a. The switching request signal activates the monitor cell insertion circuit (hereinafter referred to as N8) 5, and inserts the monitor cell M into the incoming line. In this embodiment, it is assumed that the cell is inserted after cell A. Maru A, M, B, C~
passes through 5PIO and is connected to the monitor cell extraction circuit (EXT
) 20 extracts the υ monitor cell M and sends it to the monitor cell coincidence detection circuit (hereinafter referred to as DET) 6. At this time, the cells B, C~ following the monitor cell M remain stopped by the EXT20. On the other hand, copy cells A' t M'rB', C
'~ passes through 8P11 (standby system), and monitor cell M' is extracted by EXT21 and sent to DET6. At this time, cell B/ follows monitor cell M'.

C/~ remains stopped at EXT21.

DET6 sends out a coincidence signal when monitor cells M and M' arrive. This match signal is the switching circuit control logic circuit (
(hereinafter referred to as LOG) is sent to 7 and drives SW4 to change the output line to 5.
At the same time as switching to the PII side, cells B and C are also sent to EXT20 and 21 and are stopped at EXT20 and 21.
-jr, B/, C'~ are permitted to be transmitted. As a result, the cells B/, C/~ are sent to the outgoing line. In other words, switching from 5PIO to 8P11 has been executed.

[Effect of Kishu]

As explained above, according to the present invention, in an ATM switch network, switching to the protection system is performed using the matching signal of the monitor cell extracted from both the working and protection systems, thereby achieving the effect of optimal system switching. There is.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. 10.11...ATM switch communication path (sp)
, 20.21...Monitor cell insertion circuit (EXT
), 3... Input cell distribution circuit (DST), 4.
... Switching circuit (SW), 5 ... Monitor cell insertion circuit (INS), 6 ... Monitor cell coincidence detection circuit (DET), 7 ... Switching circuit control Logic circuit (LOG), 8... Call path control circuit (8P
C).

Claims (1)

[Claims] A distribution circuit that distributes input cells of an incoming line to working and protection communication paths, an insertion circuit that inserts monitor cells for switching control into the input line, and an extraction circuit that extracts monitor cells to the output sides of both systems. , in an asynchronous transfer mode switch network having a working system and a protection system, and a switching circuit that connects one of the outputs of both systems to the outgoing line as the working system, when switching to the protection system, the monitor cell is connected to the incoming line. A channel system switching control system characterized in that the communication path system switching control method is characterized in that the switching to the protection system is performed at the time when a matching signal of a monitor cell extracted from both the working system and the protection system is detected.