JPH03143118A - Bypass control system for transmission line - Google Patents

Abstract

PURPOSE:To bypass a faulty transmission line in response to the capacity of a bypass destination transmission line by determining a time slot of a bypass object and a bypass destination transmission line in advance and displaying whether or not the bypassing state is reached for each time slot representing the bypass so as to discriminate the propriety of the bypass. CONSTITUTION:If a transmission line 11 is faulty, a time division multiplexer 1 retrieves a table of the transmission line 11 in a bypass object time slot table 14 of its own equipment. Then a bypass destination transmission line number and a bypass object time slot number are detected. Succeedingly, a bypass time slot table 15 is retrieved to check whether or not the bypass time slot of a transmission line 13 being a bypass destination is busy. A time division multiplexer 2 replies the enabled bypass to the time division multiplexer 1 when enabled bypass is discriminated similarly. Thus, data using the time slots 1, 2 by the time division multiplexers 1, 2 are switched to use time slots 7, 8.

Description

[Detailed Description of the Invention] [Summary] Regarding a transmission path detour control method, the purpose of the present invention is to provide a transmission path detour control method that can detour even when a failure occurs in multiple transmission paths. ) is connected by multiple transmission paths, a first table consisting of detour destination transmission path numbers and detour target time slot numbers in the event of a failure in the plurality of transmission paths, and a detour route time on the detour destination transmission path. A second table consisting of a slot number and an indication of whether the time slot is in use is provided in each device, and when a transmission path failure occurs, both devices search the first table and determine the detour destination transmission path and the detour target. After finding the detour time slot, when the second table is searched to find an available detour route time slot on the detour destination transmission path, the communication in the detour target time slot is moved to the detour route time slot, and the second table is searched. In the table No. 2, the detour route time slot is indicated as being in use.

[Industrial application field]

The present invention relates to a detour control method for a transmission path, and more particularly to a detour control method within a time division multiplexing device when a transmission path failure occurs when the time division multiplexing devices are connected by a high-speed digital line.

In a system where time division multiplexers are connected via high-speed digital lines, if a transmission line failure occurs, the failed line is detoured to another healthy transmission line to prevent communication disruption. .

This kind of transmission line detouring method is such that when a failure occurs in multiple transmission lines, even if a certain transmission line is defined as a detour optical path for multiple failed transmission lines, the detour is performed according to its capacity. It is requested that it be possible.

[Conventional technology]

In the conventional transmission route detour method, detour control of the transmission route in the event of a transmission route failure is performed for each transmission route, and if a part of a transmission route is already being used for detour, Furthermore, detours that would use that transmission line as a detour route were not allowed.

Figures 6(a) and 6(b) show the conventional transmission line detouring method, where (a) shows a detour definition table for detour control, and (b) shows a detour status management table. There is.

The detour definition table contains, for each transmission path, the detour destination transmission path number in the event of a failure on that transmission path, and each detour target time slot number that should be detoured in the event of a failure on that transmission path. It is written in advance along with the time slot number of the detour route.

The detour status management table also displays the transmission line status of each transmission line that becomes the detour light along with the transmission line number.

When a certain transmission line, for example, transmission line 1, becomes a failure, the transmission line state management table is checked, and when the transmission line to be detoured, for example, transmission line 3, is usable, each detour target time of the failed transmission line 1 is determined. By performing the process of detouring the slot to the corresponding detour route time slot of the transmission path 3, detour control of the failed transmission path 1 can be performed.

[Problems to be Solved by the Invention] Therefore, in the conventional transmission route detour control system, it is possible to define one detour destination transmission route for multiple faulty transmission routes, but the detour processing is exclusive. It can only be executed. Therefore, if a plurality of transmission lines fail at the same time, detour processing can only be executed for one of the transmission lines.

The present invention is an attempt to solve the problems of the prior art, and the present invention aims to solve the problems of the prior art.When a failure occurs in a plurality of transmission lines, a certain transmission line is defined as a detour light for the plurality of failed transmission lines. The purpose of the present invention is to provide a detour control method for a transmission line that can be detoured according to its capacity even when there is a transmission line.

[Means to solve the problem]

The present invention, as shown in FIG. 1, is a system in which time division multiplexing devices (hereinafter referred to as devices) 1 and 2 are connected by a plurality of transmission paths. Table 5 is provided in each device 1.2, and when a transmission path failure occurs, both devices 1 and 2 search the first table 4 to find the detour destination transmission path and detour target time slot, and then When searching table 5 and finding a detour route time slot that can be used on the detour destination transmission path, the communication in the detour target time slot is moved to the detour route time slot, and in the second table 5, the communication in the detour route time slot is currently being used as the detour route time slot. It is designed to display the following information.

Here, the first table 4 describes detour destination transmission path numbers and detour target time slot numbers in the event of a failure in a plurality of transmission paths. Further, the second table 5 describes detour route time slot numbers on the detour destination transmission path and an indication of whether this time slot is in use.

[Effect]

In the present invention, each time division multiplexer has a detour target time slot table and a detour route time slot table for each transmission line.

FIGS. 2(a) and 2(t)) show the basic configurations of the detour target time slot table and the detour route time slot table, respectively.

In the detour target time slot table shown in FIG. 2(a), the number of the transmission line to be detoured when the transmission line fails and the time slot number to be detoured from the failed transmission line are listed.

In addition, in the detour route time slot table shown in Figures 2~), for each transmission line that becomes a detour route in the event of a failure of a certain transmission line, the number of time slots that can be used as a detour route, and the time slot that has already been used as a detour route are shown. A flag indicating whether or not it is used is written.

When a certain transmission path becomes faulty, the time division multiplexer uses the detour route timeslots and detours of the detour destination transmission path listed in the detour target time slot table for the failed transmission path.
The table is searched, and if the number of unused detour route time slots is greater than the number of detour target time slots, it is determined that detour is possible.

If the detour is possible, the detour processing is performed by changing the transmission path so that the data that used the detour target time slot uses the detour route time slot of the detour optical transmission path.

Therefore, in the detour control method of the present invention, when a failure occurs in multiple transmission lines, even if a certain transmission line is defined as a detour light for multiple failed transmission lines, the detour is performed according to its capacity. It can be performed.

〔Example〕

FIG. 3 shows an embodiment of the present invention, and shows a simple configuration example of a network targeted by the present invention.
, 2 are time division multiplexing devices, 11, 12.13 are transmission lines, 3 are communication means respectively provided in the time division multiplexing device 1.2, and 14 are time division multiplexing devices 1.2.
A detour target time slot table 15 is provided in each of the time division multiplexing devices 1.2, and a detour route time slot table 15 is provided in each of the time division multiplexers 1.2.

4A and 4B show a specific example of a detour target time slot table, and FIG. 5 shows a specific example of a detour route time slot table.

The detour target time slot table 14 and the detour route time slot table i5 are stored in the time division multiplexing device 1.2.
Each is defined similarly in .

In the detour target time slot table 14, a detour target transmission route number and a detour target time slot number to be detoured in the event of a failure in the transmission route are determined for each transmission route. For example, when the transmission line 11 is in trouble,
) as shown in FIG.
take a detour to

On the other hand, in the detour route time slot table 15, time slots to be used as detour routes and their usage status are listed for each transmission path. For example, as shown in FIG.
2 is defined as the time slot of the detour route, and a flag is set to indicate that each time slot 7 to 12 is in use.

Now, when the transmission path 11 becomes a failure, the time division multiplexing device 1 with the lowest number searches the table for the transmission path 11 in the detour target time slot table 14 of its own device, and selects the detour destination transmission path. A number (for example, transmission line 13) and a detour target time slot number (for example, time slot 1.2) on transmission line 11 are detected. Subsequently, the detour route time slot table 15 is searched to check whether the detour route time slot of the transmission line 13 serving as the detour light is in use.

When no flag is set for the six detour route time slots 7 to 12 of the transmission line 13, it is determined that they are unused and can be detoured. Inquire whether a detour is possible.

Similarly, the time division multiplexing device 2 searches the detour target time slot table 14 and the detour route time slot table 15 of its own device, and when it is determined that detour is possible by that route, the communication means 3 is A response indicating that the detour is possible is returned to the time division multiplexing device 1 via the detour. As a result, in the time division multiplexers 1 and 2, the data that used time slot 12 of transmission line 11 is switched to use time slot 7.8 of transmission line 13.

At this time, since the detour route time slot 78 of the transmission line 13 was used, in the detour route time slot table 15 of both time division multiplexers 1 and 2, the time slot 7
．． Set a flag indicating that 8 is in use. This completes the detour processing when the transmission line 11 fails.

Furthermore, when the transmission line 12 becomes a failure, the time division multiplexers 1 and 2 search the detour target time slot table 14 in the same way as in the case described above, and then the detour route time of the transmission line 13 that becomes the detour light is searched. Search slot table 15.

In this case, since the four detour route time slots of time slots 9 to 12 of the transmission path 13 are not flagged and are not used, it is determined that a detour is possible, and the time division multiplexer 1.2 The detour target time slot (
For example, data that used time slots 1 to 4) is switched to use time slots 9 to 12 of the transmission path 13.

At this time, the detour route time slots 9 to 1 of the transmission line 13
2 was used, the time division multiplexer 1. In the detour route time slot table 15 of No. 2, the transmission path 13
A flag indicating that the detour route time slots 9 to 12 are in use is set. This completes the detour processing when the transmission line 12 fails.

When the faulty transmission line is restored, the normal state is restored by performing the reverse process to the above.

〔Effect of the invention〕

As explained above, according to the present invention, the detour destination transmission path and the time slot to be detoured in the event of a transmission path failure are determined in advance, and it is determined whether or not the detour is in progress for each time slot that is the detour route. Since we have made it possible to judge whether a detour is possible using the information shown, when a failure occurs on multiple transmission paths, a certain transmission path is defined as the detour destination transmission path for multiple failed transmission paths. Even in such a case, the failed transmission path can be detoured according to the capacity of the detour destination transmission path.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the basic configuration of the present invention, Fig. 2(a),
(b) is a diagram showing the basic configuration of a detour target time slot table and a detour route time slot table, FIG. 3 is a diagram showing an embodiment of the present invention, and FIG. 4 (a).
b) is a diagram showing a specific example of a detour target time slot table, FIG. 5 is a diagram showing a specific example of a detour route time slot table, and FIG. 1. 2 is a time division multiplexing device (apparatus), 4 is a first table, and 5 is a second table. FIG. Figure 3 shows an example of the detour target time slot table Detour route time slot table (a) (b) (a) (b) Figure 4 shows a specific example of the detour target time slot table Transmission path 13 Flag detour route time slot te!c:S Figure detour definition table showing a specific example of pull (a) Figure 6 showing the conventional transmission receiving detour state management table detour method

Claims (1)

[Scope of Claims] In a system in which time division multiplexing devices (hereinafter abbreviated as devices) (1, 2) are connected by a plurality of transmission paths, a detour destination transmission path number and a detour when a failure occurs in the plurality of transmission paths. The first table consisting of the target time slot number (
4), and a second table (5) consisting of the detour route time slot number on the detour destination transmission path and an indication of whether the time slot is in use is provided in each device (1, 2), and in the event of a transmission path failure. , both devices (1, 2) search the first table (4) to find the detour destination transmission path and the detour target time slot, and then search the second table (5) to find the detour destination transmission path. When a usable detour route time slot is found on the detour route, communication in the detour target time slot is moved to the detour route time slot, and a second
A detour control method for a transmission path, characterized in that the detour route time slot is displayed as being in use in the table (5).