JP2595804B2 - Exchange equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is used for an ATM (Asynchronous Transfer Mode) type switch network. In particular, it relates to a redundant configuration when a failure occurs in a switch network.

〔Overview〕

According to the present invention, in a redundant configuration means of an asynchronous transmission mode switch network of a switching device, an economical redundant configuration can be realized by bypassing a cell passing through a failure unit switch via another link. It is made possible.

[Prior art] In the conventional example, an identical switch network is duplicated,
When a failure occurs in one switch network, the entire network has generally been switched to the other switch network for use. FIG. 5 shows the configuration of this conventional example. In this example, there are two switch circuit networks having a three-stage configuration, a 0-system switch network 20 and a 1-system switch network 21, and a switching circuit 3 for selecting which one to use and a switching control circuit for instructing switching. 4. Now 0
Assuming that the system switch network 20 is used as a working system for communication, the system switch network 21 is in a state of being used as a standby system. Here, one of a plurality of switch groups in the 0-system switch network 20 is selected.
Assuming that a failure has occurred, the switching control circuit 4 issues a switching instruction to the switching circuit 3 to switch all the incoming and outgoing lines to the 1-system switch network 21, and then searches for a failure in the 0-system switch network 20. Do. After confirming restoration by replacing a faulty switch or the like, the system was switched back to the 0-system switch network 21 and used again.

[Problems to be solved by the invention]

As described above, in the conventional example, since a network including many unit switches is doubled and a switching circuit and a switching control circuit are also required, it is extremely disadvantageous in terms of cost and space. Was. In addition, even when a failure occurs in a part of the switch network, the entire switch network is switched, so that all calls in communication are affected, and continuity is maintained by switching calls in use in parts other than the failure part. Therefore, there is a disadvantage that a complicated circuit or software control is required.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate such disadvantages and to provide a switching device in which the configuration of a switch network is spatially expanded and the speed is increased.

[Means for solving the problem]

The present invention has a multistage configuration in which unit switches are connected by a link, includes a switch network in an asynchronous transmission mode, and a control device that controls link connection of the switch network. As means for performing this, the switch network includes first circuit means for multipoint connection between the input line and a plurality of unit switches constituting the first stage for each input line, and this output line and the last stage for each output line. And a second circuit means for connecting a plurality of multipoints of the unit switch constituting the above, wherein the link is constituted by a device having a transmission speed of twice or more the transmission speed of the incoming line and the outgoing line, and the control device comprises: Means for switching the path of a cell passing through the unit switch in which the fault condition has occurred and passing the other unit switch of the stage to which the unit switch in which the fault condition has occurred belongs. To.

[Action]

The input side multi-connects one input line to a plurality of unit switches, the output side multi-connects a plurality of unit switches to one bill, and inputs the link speed between each switch stage.
It is larger than the outgoing line, and when a failure occurs, only the unit switch of the failure is closed, and the cell passing through the switch is diverted to another link.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

 FIG. 1 is a block diagram showing this embodiment.

That is, this embodiment has a multistage configuration in which unit switches are connected by links as shown in FIGS. 1 and 2, and a switch network 10 in an asynchronous transmission mode and a link between the switch networks 10. And a control device 15 for controlling the connection. Further, as a feature of the present invention, the switch network 10 includes, for each of the input lines 1, 2, ..., 8, an input line 1 (2, ..., 8) Unit switch 100 constituting the first stage
And 101 (110 and 111,..., 180 and 181) in a multipoint connection, and outgoing lines 1, 2,.
, 8, and the outgoing line 1 (2,..., 8) and the unit switches 300 and 301 (310 and 311,.
0 and 381), and the link has a transmission speed higher than the transmission speed of the incoming line and the outgoing line. There is provided a means for switching a path of a cell passing through the unit switch and passing another unit switch belonging to the stage to which the unit switch belongs.

 Next, the operation of this embodiment will be described.

FIG. 2 shows an example of a case where both switch network configurations are normal (no failure), and FIG. 3 shows that a unit switch fails and a cell of a call using the failed switch bypasses another link. Shows the status of In the normal state, the cells of the call coming in from the incoming line are divided into the first unit switch 100-181, the second unit switch 200-281, the third unit switch 30 according to the preset path information.
Go to the desired outgoing line through any of 0-381. FIG. 1 shows a case where a cell that has entered from an incoming line 1 in a three-stage switch configuration passes through unit switches 100, 200 and 300 and exits to an outgoing line 1. FIG. 3 shows a case where the unit switch 200 has a failure.
Cells that passed through 00, 200 and 300 are unit switches 10
The route will pass through 0, 201 and 300.

In addition, the input line and the output line are multi-connected to a plurality of unit switches for switching when the unit switch of the first stage accommodating the incoming line and the unit switch of the last stage accommodating the outgoing line fail. One incoming line or one outgoing line is connected to a plurality of unit switches at the same time). This image is shown in FIG. In addition, when a cell passing through the unit switch that has failed is diverted to another switch, the traffic of the other switch is squeezed. This is dealt with by increasing the link speed of the switch above the line speed. FIG. 4B shows an image of the speed-up. This example shows a case where the link speed is twice the line speed.

〔The invention's effect〕

According to the present invention, as described above, there is an effect that an economical redundant configuration can be obtained as compared with a system in which the same switch network is set twice and a switching circuit, a switching control circuit, and the like are also installed. Further, only cells of calls passing through the failure unit switch are affected by instantaneous interruption or the like due to detour switching, and cells of many calls passing through other switches are not affected at all. Further, since the switching of the switch can be performed in exactly the same procedure as the route setting at the time of normal call setting, there is an effect that a control circuit and software for call setting can be utilized. In addition, since the link speed is set higher than the line speed, the cell discard characteristics and the like are improved in a normal state,
There is an effect that high quality communication can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. FIG. 2 is a diagram showing a normal state of the embodiment of the present invention. FIG. 3 is a diagram showing a state when a failure occurs in the embodiment of the present invention. FIG. 4 is a diagram showing a spatially enlarged configuration and an enlarged image of a link speed. FIG. 5 is a block diagram showing a configuration of a conventional example. 3 switching circuit, 4 switching control circuit, 10 switch network, 15 control device, 20 system switch network, 21 system switch network, 100, 101, 11
0, 111-180, 181, 200, 201-280, 281, 300, 301-38
0, 381 ... Unit switch.

Claims (1)

(57) [Claims] 1. A switching device having a multistage configuration in which unit switches are connected by a link and comprising a switch network in an asynchronous transmission mode and a control device for controlling a link connection of the switch network. The circuit network includes, for each input line, first circuit means for multipoint connection between the input line and a plurality of unit switches constituting the first stage, and, for each output line, a unit circuit constituting the output line and the last stage. A second circuit means for multi-point connection with a plurality of links, wherein the link is constituted by a device having a transmission speed twice or more as high as the transmission speed of the incoming line and the outgoing line, and A switching device for switching a path of a cell passing through the unit switch and passing another unit switch of a stage to which the unit switch in which the fault state has occurred belongs; .