JPH06311227A - Switching device with N + 1 redundant configuration - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To improve economic efficiency, feasibility, and reliability. [Configuration] L devices A are switching devices SE and M, respectively
It is connected to device B by a set of duplex links. One spare is provided for N devices B, and the switching device has a so-called N + 1 redundant configuration. For an integer K of 2 or more and L × M or less, 2K changeover switches 502, 502 ′ having L × M × N ÷ K terminals on the device A side and L × M × (N + 1) ÷ K terminals on the device B side. Prepare 512, 512 'and 2
It is installed by dividing into J pieces (J = 2 in FIG. 1) of the first and second switching devices (1 device for 500 and 501 and another device for 510 and 511) of 2K or less and J = 2. Connect 1
The 0-system (1st digit is 0) link and the 1-system (1st digit is 1) link of the pair of duplicated links are accommodated in different first and second switching devices.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a switching device for a redundantly configured device such as an electronic exchange which is required to have high reliability. The present invention relates to a configuration of a switching device having an N + 1 redundant configuration in the case of assuming a double failure and further adopting an N + 1 redundant configuration.

[0002]

2. Description of the Related Art A configuration technique of a conventional switching device having an N + 1 redundant configuration will be described with reference to FIG. 10 in FIG.
Reference numerals 0 and 101 are the first type devices, which will be referred to as device A. The device A has a dual redundant configuration to improve reliability, and 100 is a 0-system device and 101 is a 1-system device. 110 and 111, 120 and 121, 130 and 131
Is a similar device A. Also, 400 and 401 are the second type of devices and will be referred to as device B. Like the device A, 400 is a 0-system device and 401 is a 1-system device. 410
And 411, 420 and 421 are also device B. 700
And 701 are switching devices, and the 0-system switching device 700 is composed of a changeover switch 702 and a changeover switch control circuit 703. Although not shown in FIG. 3, the 1-system switching device 701 has a similar configuration.

Assuming that the connection of the changeover switch 702 is in the state shown by the alternate long and short dash line and the solid line, 100 and 101, 110 and 111 of the device A and 400 and 4 of the device B, respectively.
01 and 120 and 12 of the device A, respectively.
1, 130 and 131 are connected to 410 and 411 of device B, respectively. In the case of the electronic exchange system, the device A is, for example, a subscriber line accommodation device, and the device B is, for example, an exchange processing device. In FIG. 3, N = 2 to simplify the drawing.
Of the device B (400, 401 sets and 41 sets).
This is an example in which one set of backup devices B (420 and 421) is provided for 0, 411 sets), but N may be any number. Further, although one device B accommodates two devices A, an arbitrary integer L of devices A may be accommodated, and one device A (for example, 100 and 101) may be accommodated.
Sets of links (eg 200,201 sets or 300,3
01 set) is connected to one set of devices B (for example, 400 and 401), but this may also be connected by an arbitrary integer M set of links. In that case, on the device A side (L × M × N)
A switch for switching the terminal and the device B on the {L × M × (N + 1)} terminal is required for the 0-system and 1-system switching devices 700 and 701, respectively.

When the number L of the devices A accommodated in one device B increases, the influence of the failure of the device B is great. Therefore, in order to improve the reliability, N duplicated devices B are used. On the other hand, it is effective to provide one redundant spare device B. This is in consideration of the double failure of the duplicated device. In general, the probability that a 0-system device and a 1-system device of a duplicated device will have a double failure is extremely higher than the probability that two completely independent devices will simultaneously fail. This is because the two systems of the duplexer do not operate completely independently, and a failure of one system may affect the other system. When the duplexing devices B400 and 401 have a double failure by switching the connection indicated by the alternate long and short dash line of the changeover switch 702 in FIG. 3 to the connection indicated by the broken line, the spare devices B420 and 421 are replaced. It is possible to

[0005]

However, in the switching device constructed by this conventional technique, the number of duplexers B (N +
1) One device B (each of the duplication devices is a single unit)
The number of devices A accommodated in a room (L), one device A and one device B
If the number (M) of links connecting the two switches increases, the size of the changeover switch of the changeover device increases, which makes it difficult to realize the changeover switch, which is uneconomical and reduces reliability.

Further, the switching devices 700 and 701 are also duplicated devices, and there is a possibility that a double failure of the switching device will occur with the same probability as the double failure of the 0-system and 1-system of the device B. N +
There is a problem that it is difficult to improve the reliability due to the N + 1 redundant configuration because the failure spreads to the same extent as the failure of one full-duplex device B. The object of the present invention is to make the conventional switching device economical,
An object of the present invention is to provide a switching device having an N + 1 redundant configuration, which solves the problems of feasibility and reliability and is excellent in economic efficiency, feasibility, and reliability.

[0007]

A conventional switching device 7 shown in FIG.
00 and 701 each use two changeover switches of (L × M × N) terminal on the device A side and {L × M × (N + 1)} terminal on the device B side. N + 1
The switching device having a redundant configuration is provided on the device A side (L × M × N ÷ K).
2 terminals {L × M × (N + 1) ÷ K} on the device B side
A plurality of (J) switching devices that accommodate the changeover switches are used by using × K changeover switches (where K is an integer of 2 or more and the number of divisions of the changeover switch 702 is L × M or less).
Installed (where J is an integer of 2 or more and 2 × K or less), and a set of links connecting device A and device B, that is, device 0 of system 0 and device B of system 0 are connected. The above problem is solved by configuring the 0-system link and the 1-system link connecting the 1-system device A and the 1-system device B to be accommodated in different switching devices.

[0008]

In the present invention, the total number of crosspoints of the changeover switch used in the changeover device of the N + 1 redundant configuration (the number of one terminal of the switch × the number of the other terminal of the switch × the number of switches) is 1 compared with the conventional one. / K, so
The cost efficiency, feasibility, and reliability of the switching device are improved.

Further, since the 0-system link and the 1-system link connecting the device A and the device B are accommodated in different switching devices, even if one switching device becomes a total failure, the failure propagation range is the entire device. The reliability can be improved by the N + 1 redundant configuration without affecting A and device B.

[0010]

[Embodiment 1] FIG. 2 shows a first embodiment of the present invention. Like FIG. 3, L = 2, M = 1, N =
2 is an example. The description from 101 to 421 is the same as the description of the conventional technique. In this example, the number of divisions K of the changeover switch 702 is K = 2, and four changeover switches 601, 611, 621, and 631 used for the N + 1 redundant configuration changeover device are installed. ing. K is generally an integer of 2 or more and L × M or less.
The conventional changeover switch 702 of the changeover device 700 (701) of FIG. 3 is divided into two changeover switches 611 and 631 (601 and 621) of the changeover devices 610 and 630 (600 and 620). The number of divisions J of the entire switching device is J = 2 in FIG.
However, J = 4.

Device B 400 and 401, 410 and 411
In the case where 400 and 401 of the device B have a double fault, the connection of the dashed-dotted line of the changeover switch is switched to the connection of the broken line, and the device B 420 and 421 are connected to the device A 100. 101, 110 and 111 can provide the service without any problem. Switching is possible even when there is a double failure in 410 and 411 instead of 400 and 401 of device B, and there is no deterioration of the switching function due to the division of the changeover switch. In FIG. 2, N = 2, M = 1, L = 2, K =
Although the example of No. 2 is shown, N, M, L, and K may be any numbers. In that case, on the device A side (L × M × N ÷
K) terminal, 2 × K switch switches of {L × M × (N + 1) ÷ K} terminal and 2 × K switch control circuit are prepared on the device B side, and 2 × K switch devices can be installed. Good.

The number of cross points of the change-over switch in the case of the conventional technique is such that the number of terminals on the device A side is (L × M ×
N), the number of terminals on the device B side is {L × M × (N + 1)}, the number of changeover switches is 2, and 2 × L ² × M ² × N × (N
+1). On the other hand, in the configuration of the present invention, the number of terminals on the device A side is (L × M × N ÷ K), and the number of terminals on the device B side is {L × M.
× (N + 1) ÷ K}, the number of changeover switches is 2 × K, and the number of cross points is 2 × L ² × M ² × N × (N +
1) ÷ K, which is 1 / K of the conventional technique. Therefore, to minimize the total number of cross points, the maximum value of K,
That is, K = L × M may be selected. Since the total number of cross points is reduced in the configuration of the present invention, there is an advantage that the cost efficiency, feasibility, and reliability of the switching device are improved.

Further, since the switching device having the N + 1 redundant configuration is divided and configured, there is an advantage that the reliability of the device B can be improved by the N + 1 redundant configuration even if a failure occurs in the switching device. Referring to FIG. 2, the switching device 60
If 0 becomes an obstacle, links 201, 221, 30
1, 321 and 341 cannot be used, but the switching device 61
0 and one of the switching devices 620 and 630 can connect the device A and the device B without any problem, and even if one of the three devices B fails, the service can be maintained without any problem. [Embodiment 2] FIG. 1 shows a second embodiment of the present invention, and shows the configuration of a switching device which is more economical than the first embodiment.

In the first embodiment, the number of divisions K of the changeover switch is K.
Although it has been described that it is economical to increase the number of changeover switches because the total number of changeover switches decreases, but the amount of hardware such as a switch control circuit fixedly required for each changeover device increases. Therefore, in the second embodiment, the number of divided changeover switches is 2 ×.
A method of setting the number of switching devices to J while keeping K will be described. Here, J is an integer greater than 2 and not exceeding 2 × K. In FIG. 1, N = 2, M = 1, L = 2, K = 2, J = 2
No. 101 to 421 are the same as those described above, and 500 and 501 are the first switching devices 510 and 511.
Is the second switching device.

Since the changeover switch is divided into K pieces as compared with the prior art, the effect of improving reliability, feasibility and economical efficiency by reducing the number of cross points is the same as that of the first embodiment. In the second embodiment, the 0-system links 200 and 210 of the devices A 100 and 110 are connected to the second switching devices 510 and 511, and the 1-system links 201 and 211 are connected to the first switching devices 500 and 501. ing. Similarly, the 0-system links of the other devices A and B are connected to the second switching device and the 1-system links are connected to the first switching device. It is easy to accommodate the 0-system link and the 1-system link of the device A and the device B in different switching devices regardless of the value of the division number J of the switching device between 2K and 2K. Even if one of the devices becomes a total failure, all the redundant devices A are duplicated by N + 1 by using the 0-system or 1-system links that are not accommodated in the failed switching device. Since it can be connected to the device B, the reliability can be improved by the N + 1 redundant configuration of the device B. In the example of FIG. 1, since K = 2, only J = 2 can be selected. However, if K is set to a larger number and J is set to a smaller number, hardware such as a switch control circuit fixedly required for each switching device is fixed. The amount is economical without increasing.

The plurality of changeover switches in each changeover device (for example, the switch 502 in 500 and the switch 502 'not shown in 501) are not shown as the changeover switch 702 of FIG. 3 described in the prior art. They are not redundant with each other like 702 '. However, since the plurality of changeover switches in each device are controlled to the same connection state, the switch control circuit (503 in the above example) can be commonly used.

In the above description, the device A and the device B are two.
Although the device A and the device B are not necessarily duplicated, the device A and the device B do not necessarily have to be duplexed, and one device A and one device B are configured by one set A and one device B, respectively. If the link unit connecting the device B is duplicated, it is possible to realize an N + 1 redundant configuration switching device having the same advantage. Further, in the above description, it is assumed that one spare device is provided for N devices, but the same switching device can be realized even if the number of spare devices is plural.

[0018]

According to the present invention, the total number of cross points of the changeover switch used in the switching device having the N + 1 redundant configuration (the number of terminals on the device A side of the switch × the number of terminals on the device B side of the switch × the number of switches) is the same as the conventional one. Since it is reduced to 1 / K as compared with the conventional one, there is an advantage that the cost efficiency, feasibility, and reliability of the switching device are improved.

Further, since the 0-system link and the 1-system link connecting the device A and the device B are accommodated in different switching devices, even if one switching device has a total failure, the failure propagation range is the entire device. There is also an advantage that the reliability can be improved by the N + 1 redundant configuration without affecting the A and the device B.

[Brief description of drawings]

FIG. 1 is a connection diagram showing a second embodiment of the present invention.

FIG. 2 is a connection diagram showing a first embodiment of the present invention.

FIG. 3 is a connection diagram of a conventional switching device having a 2 + 1 redundant configuration.

[Explanation of symbols]

100, 110, 120, 130: Device A (0 system) 101, 111, 121, 131: Device A (1 system) 201-350: Link connecting device A and device B 400, 410, 420: Device B ( 0 system) 401, 411, 421: Device B (1 system) 500, 510, 700: Switching device (0 system) 501, 511, 701: Switching device (1 system) 600, 610, 620, 630: Switching device 502 , 512, 601, 611, 621, 631, 7
02: Changeover switches 503, 513, 602, 612, 622, 632, 7
03: Control circuit for changeover switch

Claims (1)

[Claims] 1. One or a plurality of L first type devices (referred to as a device A) are respectively derived from a switching device and both side terminals of the switching device.
N + 1 redundant configuration, connected by a set of duplex links to a second type of device (called device B, where one spare device B is provided for N devices B) In the switching device of the above, for the integer K of 2 or more and L × M or less, (L
× M × N ÷ K) terminal, on the device B side above {L × M × (N +
1) ÷ K) 2 × K changeover switches having terminals are prepared, divided into 2 or more and 2 × K or less J changeover devices, and connected to the device A and the device B 1 In the N + 1 redundant configuration, the 0-system link and the 1-system link of the duplicated links of the set are respectively accommodated in different ones of the J switching devices. Switching device.