JPH0570345B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a contention control system when a collision occurs in selected routes in a self-route selection type switching network.

[Conventional technology]

The literature LTWu and NCHuang, “Synchronous
Wideband Network−An Interoffice Facility
There is a Batcher Banyan Network described in "Hubbing Network" Zurich Seminar 1986. The configuration of this switching network is shown in Figure 5. In this switching network, input terminals 1, 2, 3, 4 and address values 00, 01,
Output terminals 5, 6, and 10 and 11 are respectively given.
Between 7 and 8 is the distribution network 25 (Batcher Network)
and a routing network 26 (Banyan Network), and each network is connected to a unit switch 11.
~16, 21~24.

Unit switches 11, 12, 13 of distribution network 25,
The exchange operations at 14, 15, and 16 are shown in Fig. 6a,
Shown in b, c, d. The unit switch indicated by the ↓ mark connects the input with the larger value of the routing address to the lower output, and the unit switch indicated with the ↑ mark connects the input with the larger value of the routing address to the upper output. Switch so that the input is connected.

Unit switches 21 and 2 of the routing network 26
At steps 2, 23, and 24, switches are performed as shown in FIG. 6e and f according to the bit value r of the routing address assigned to each stage.

For example, in the distribution network 25 and the routing network 26 made up of unit switches according to the above algorithm, if signal blocks destined for output terminals 8, 7, and 5 arrive at input terminals 1, 2, and 4 at the same time, Routing is performed autonomously as shown in FIG. In addition, the distribution network 25
In this case, each unit switch performs exchange control on the assumption that the input in the free state is greater than all address values. In the routing network 26, unit switches 21 and 23 operate for the upper bits of the routing address, and unit switches 22 and 24 operate for the lower bits.

The above is a description of the prior art. In this prior art example, a collision occurs when signal blocks for the same destination arrive at different input terminals at the same time. FIG. 7 shows a state in which the signal block to the output terminal 8 arrives at the input terminals 1 and 4 at the same time, and the signal block to the output terminal 8 collides with the unit switch 15. That is, this conventional example has a problem in that signal blocks are discarded due to collisions.

In order to avoid such problems, a method has been considered in which a buffer is provided for each unit switch and signal blocks are waited for in the event of a collision, but this method has the drawback of increasing the total buffer amount.

SUMMARY OF THE INVENTION An object of the present invention is to provide a contention control system in a self-route switching network that eliminates the need to discard signal blocks when signal blocks collide without providing a buffer for each unit switch.

[Means for solving problems]

The present invention is a contention control method in a self-route switching network in which routing information is added to blocked user information and routes are autonomously determined based on the routing information. a first switching network that sets a route of
a second switching network that sets a second route that is the same as the route of the second route corresponding to the first route set up to the collision point of the signal whose setting is prohibited;
The second route of the switching network is used to notify the corresponding input terminal that the route setting has been interrupted midway.

〔Example〕

Embodiments of the present invention will be described using FIGS. 1 to 3.

The switching network shown in FIG. 1 shows an example in which the present invention is applied to the conventional example shown in FIG. They are connected by a signal path in the opposite direction. In the figure, unit switch 11
Although only the signal path between the upper input terminal and the upper input terminal of the unit switch 15 is shown as being duplicated, all the signal paths between the unit switches in the distribution network 25 are composed of paired signal paths. There is. Each unit switch also has a switching function for signals flowing in the opposite direction. In addition, input terminals 1, 2 of the exchange network,
3 and 4 are transmission buffers 10-1 and 10-, respectively.
2, 10-3, and 10-4.

Figure 2 shows the configuration of the signal block, and the user information INFO contains the routing address RI.
is added.

FIG. 3 shows the configuration of a unit switch in the distribution network 25, and shows a switch element 31 (an element constituting the first switching network) through which a signal block passes and a signal indicating a contention state (contention detection signal). Switch element for opposite direction of flow (second
a control unit 30 that performs switching control by comparing the routing addresses of two input signal blocks;
for supplying the conflict detection signal to the opposite signal path.
It is composed of OR gates 33 and 34.

The switch element 31 has two selectors 31
-1 and 31-2, and the switch element 32 is composed of two selectors 32-1 and 32-2, and each of these selectors is controlled by the control section 30 in a switching manner. In the figure, 41, 42 are input terminals of the switch element 31, 43, 44
is an output terminal of the switch element 31. 4
5 and 46 are output terminals of OR gates 33 and 34;
7 and 48 are input terminals of the switch element 32.

In the unit switch configured as described above, if the two signal blocks do not collide, the control section 30 sets the state of the switch element 31 according to the algorithm shown in FIGS. It is also set in the switch element 32. For example, input terminals 41 and 42 are connected to output terminals 44 and 43
If the selectors 31-1 and 31-2 are controlled by the control signal 30-1 so as to be connected to the output terminals 46 and 45, respectively, at the same time, the input terminals 47 and 48 are connected to the output terminals 46 and 45, respectively, by the selectors 32-1 and 32-2. Ru.

In Fig. 1, in the unit switch 11, the signal block of the routing address 11 of the upper left input terminal is connected to the lower right output terminal, but the signal path for the conflict detection signal is conversely set from the lower right to the upper left. Ru. If signal blocks with the routing address "11" are sent out from the input terminals 1 and 4 at the same time, a collision occurs in the unit switch 15. When the control section 30 of the unit switch 15 detects this, it sets the signal path for one of the signal blocks to the upper right terminal (in FIG. 3, the output terminal 43), and sets the signal path for the other signal block. and sends a conflict detection signal to the input terminal.

FIG. 1 shows a state in which the setting of the signal path is stopped for the signal block from the input terminal 1. The reason why the surviving signal block is connected to the output terminal 43 is as follows. Because one signal block is not given a signal path due to the collision,
Output terminals to which no signal block is supplied remain vacant. In the unit switch 15 marked with ↓, the 6th
As shown in Figures a and b, the signal block with the smaller routing address is output to the upper side, and the empty terminal is treated as the one with the largest routing address, so the signal that survived the contention is The block is connected to the upper side, ie to the output terminal 43. Although FIG. 1 shows an example in which the signal block supplied to the lower input terminal or from the input terminal 4 survives, an algorithm may be used in which the signal block supplied to the upper input terminal survives. In any case, the surviving signal blocks are connected to the output terminal 43.

The control unit 30 sends a conflict detection signal to the transmitting end 1 via the OR gate 33. Since the signal path from the upper left terminal of the unit switch 15 to the input terminal 1 is set by the signal block from the input terminal 1, the competition detection signal arrives at the input terminal 1 without any new control. At the input terminal 1, based on this conflict detection signal, a waiting time is established within the transmission buffer 10-1 and retransmission is performed.

In this way, by returning the conflict detection signal to the input terminal, there is no need to provide a waiting buffer for each unit switch.

In this embodiment, if no collision occurs in the distribution network 25, no collision will occur in the routing network 26, so the routing network 26 does not require an exchange section for conflict detection signals. However, as shown in FIG.
In a switching network where there is a possibility of collision in 3 and 54, a switching section for conflict detection signals is required for the entire network.

Note that the configuration of the routing switching network and the routing algorithm in this description are merely examples and do not limit the present invention.

〔Effect of the invention〕

According to the contention control method in the self-route switching network of the present invention described above, the following effects can be obtained.

(1) Signal blocks can be queued without providing a buffer for each unit switch, and the discard rate of signal blocks can be reduced.

(2) It is possible to reduce the scale of unit switches and provide a larger switching network.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of a signal block, FIG. 3 is a diagram showing the configuration of a unit switch, and FIG. 4 is a diagram showing the configuration of another switching network. FIG. 5 is a diagram showing a conventional example, FIG. 6 is a diagram showing a routing algorithm in the conventional example, and FIG. 7 is a diagram for explaining problems in the conventional example. 1-4...Input terminal, 5-8...Output terminal, 11-1
6, 21-24...unit switch, 25...distribution network, 26...routing network, 30...control unit,
31, 32...Switch element, 31-1, 3
1-2, 32-1, 32-2...Selector, 33,
34...OR gate.

Claims (1)

[Scope of Claims] 1. A contention control method in a self-route switching network in which routing information is added to blocked user information and a route is autonomously determined based on the routing information, comprising: a first switching network for setting a first route to the first switching network;
a second switching network that sets a second route that is the same as the route of the second route corresponding to the first route set up to the collision point of the signal whose setting is prohibited;
A contention control method in a self-route switching network, characterized in that a corresponding input terminal is notified that the setting of a route has been interrupted midway using a second route of the switching network.