JPH05292113A - Multiplexed path supervisory equipment - Google Patents

Abstract

PURPOSE:To avoid cell abort by providing a generating means of path supervisory information with identification information representing a source redundancy system inserted thereto to a generation point of path supervisory information and providing a termination means used when its own system is dissident with the source redundancy system based on the identification information to an intermediate detection point. CONSTITUTION:A Pi generating means 21 at a generation point A of path supervisory information (Pi) generates the information Pi including identification information representing a source redundancy system of the Pi. A 2nd normality discrimination means 22 placed at an intermediate detection point B of the Pi discriminates whether or not a path is normal based on the detected Pi. A 1st Pi termination means 23 terminates the detected Pi when its own system and a Pi source redundancy system are dissident based on the identification information included in the detected Pi. A 2nd normality discrimination means 24 at a Pi final detection point C discriminates whether or not a path is normal based on the detected Pi and a 2nd Pi termination means 25 terminates the detected Pi. Thus, one Pi is supplied to the points B,C and cell abort due to concentrated Pi information sets is avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplexed path monitoring device provided in a transmission system in which a main signal path is multiplexed between a plurality of redundant systems and monitoring whether or not the main signal path is normal. ..

Generally, an asynchronous transfer mode (hereinafter referred to as "AT
In the cross-connect device for transferring the signal of "M"), the device is made redundant so that the operation can be continued even if the device fails.

As a redundancy system in this case, for example, a path multiplexing system for multiplexing a main signal path among a plurality of redundant systems is adopted.

On the other hand, in a transmission system such as a cross-connect device, it is generally required to improve the reliability of transmission by regularly monitoring whether or not the main signal path is normal.

Therefore, when adopting the above-described path multiplexing method, it is necessary to monitor the normality of the path for all redundant systems.

[0006]

2. Description of the Related Art FIG. 7 is a block diagram showing a path configuration of a cross-connect device when a main signal path is multiplexed between two redundant systems of "0" system and "1" system.

In the figure, reference numerals 11 ₀ and 11 ₁ denote interfaces on the input side, and reference numerals 12 ₀ and 12 ₁ denote multiplexers that multiplex the main signals supplied from the interfaces 11 ₀ and 11 ₁ .

13 ₀ and 13 ₁ are multiplexing sections 12 ₀ and 12 _1.
Is a switch unit for switching a main signal supplied from the switch unit, and 14 ₀ and 14 ₁ are switch units 13 ₀ and 13 1.
15 is a separation unit that separates the main signal output from _1
0 and 15 ₁ are interfaces on the output side.

121 _{0 to} 151 ₀ and 121 _{1 to} 151 ₁
Is a selector for selectively taking in the "0" system main signal and the "1" system main signal.

In the above configuration, for example, if the "0" multiplex unit 12 ₀ fails, the multiplex unit 12 ₀ becomes "1".
It is replaced by the multiplexing unit 12 _{1 of the} system.

As a result, the "0" interface 1
A detour is formed from 1 ₀ to the switch unit 13 ₀ of the “0” system via the multiplexing unit 12 ₁ of the “1” system, and the operation can be continued.

In such a path-multiplexing type cross-connect device, in order to monitor whether or not the main signal path is normal, in general, a path monitor cell is passed through the main signal path.
This is done by determining whether or not this path monitoring cell is normally transferred.

FIG. 8 is a diagram showing the flow of the path monitoring cell when the "0" system is used as the source redundant system of the path monitoring cell.

Similarly, FIG. 9 is a diagram showing the flow of the path monitoring cells when the "1" system is used as the source redundant system of the path monitoring cells.

In FIGS. 8 and 9, a is a path monitor cell generation point, b, c, d, f, g, and h are intermediate detection points of the path monitor cell, and e is a final detection point. Is.

As shown in the figure, conventionally, the intermediate detection points b, c,
In d, f, g, and h, the path monitoring cell is passed through as it is, and the path monitoring cell is terminated only at the final detection point e.

FIG. 10 is a block diagram showing the configuration of a path supervisory cell generating device in a conventional multiplex path supervisory device for performing path surveillance by such a method. This path monitor cell generator is provided at the generation point a.

In the figure, reference numeral 21 is a path monitor cell generator for generating a path monitor cell, and reference numeral 22 is a path monitor for inserting the path monitor cell generated by the path monitor cell generator 21 into the main signal path. It is a cell insertion part.

In the path monitor cell generator 21, 211
Is a latch circuit for fetching data to be inserted into the header portion of the path monitoring cell from the path monitoring data indicating the content of the path monitoring cell.

Reference numeral 212 is a latch circuit for fetching data to be inserted into the information field from the path monitoring data.

Reference numeral 213 is a cell assembly register for generating a path monitoring cell from the data latched by the respective latch circuits 211 and 212.

In the path monitor cell insertion unit 22, 221
Is a vacant cell detection circuit for detecting a vacant cell from the input main signal.

Numeral 222 selects the path monitoring cell held in the cell register 213 when the empty cell detection circuit 221 detects an empty cell, and selects the main signal when no empty cell is detected. It is a selector.

Reference numeral 223 is a delay circuit for compensating the detection delay of the empty cell in the empty cell detection circuit 221.

In such a configuration, when an empty cell is detected, the path monitoring cell is replaced with the empty cell instead of the empty cell.
It is inserted in the path of the main signal.

FIG. 11 shows intermediate detection points b, c, d, f,
It is a block diagram which shows the structure of the path | route monitoring cell detection apparatus provided in g, h.

In the figure, 31 is a path monitor cell detecting section for detecting a path monitor cell from an input main signal,
A normality determination unit 32 determines whether the path of the main signal is normal, based on the detected path monitor cell.

In the path monitor cell detection unit 31, 311
Is a path monitor cell detection circuit that detects a path monitor cell included in the input main signal, and 312 is a cell register that holds the path monitor cell based on the detection timing of the path monitor cell detection circuit 311. is there.

In the normality judging section 32, 321 is a latch circuit for latching the data of the header section from the path monitoring data indicating the original content of the path monitoring cell, 322.
Is a latch circuit for latching data in the information field.

Reference numeral 323 is a comparison circuit for comparing the data held in the latch circuit 321 with the data in the header section output from the register 312, and 324 is the data held in the latch circuit 322 and the cell. It is a comparison circuit for comparing the data of the information field output from the register 312.

The outputs of the comparison circuits 323 and 324 are set to "H" level when both inputs match and "L" level when they do not match.

Reference numeral 325 denotes two comparison circuits 323 and 324.
It is an AND circuit that outputs an alarm signal by taking the logical product of the comparison outputs of.

The output of the AND circuit 325 becomes "H" level when the detected data of the path monitoring cell and the data for path monitoring match, and "L" when they do not match.
It becomes a level.

In such a configuration, the detected path monitor cell is passed through the path of the main signal as it is, and whether or not the path of the main signal is normal is determined based on this path monitor cell.

If the path is not normal, the AND circuit 325
Output becomes "L" level, and it is notified that the path is not normal.

For example, when the output of the AND circuit 325 of the path monitoring cell detection device provided at the intermediate detection point c in FIG. 8 becomes "L" level, it is notified that the path between bc or fc is not normal. It will be.

FIG. 12 is a block diagram showing the configuration of the path supervisory cell detection device provided at the final detection point e.

This path monitoring cell detecting device has a structure in which a path monitoring cell terminating function is added to the path monitoring detecting device shown in FIG. Therefore, in FIG. 12, the same parts as those in FIG. 11 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the figure, reference numeral 33 is a path monitor cell terminating unit for terminating the path monitor cell. In the path monitor cell terminating unit 33, 331 is an empty cell generation circuit that generates an empty cell when the path monitor cell detection circuit 311 detects a path monitor cell.

332 is a selector for selecting an empty cell output from the empty cell generation circuit 331 when the path monitoring cell detection circuit 311 detects a path monitoring cell, and for selecting a main signal when it is not detected. is there.

Reference numeral 333 is a delay circuit for compensating the detection delay of the path monitor cell in the path monitor cell detection circuit 311.

In such a configuration, when a path monitor cell is detected, this path monitor cell is replaced with an empty cell to terminate the path monitor cell.

The above is the configuration of the conventional multiplex path monitoring device provided in the transmission system having the multiplex path configuration.

As described above, the conventional multiplex path monitor device terminates the path monitor cell only at the final detection point e of the path monitor cell.

However, in such a configuration, a 2 ^m cell route is generated between the generation point a and each of the detection points b to h. Here, m is the number of stages between the occurrence point a and each of the detection points b to h.

As a result, the cell route increases as the detection point is farther from the point a, and more path monitoring cells are received.

For example, since the number of stages between the generation point a and the intermediate detection point c is 1, two cell routes occur between these two points, and the intermediate detection point c receives two path monitoring cells. It will be.

On the other hand, for example, since the number of stages between the generation point a and the final detection point e is 3, eight cell routes are generated between these two points, and the final detection point e has eight paths. You will receive a monitoring cell.

In general, when the number of multiplexing is n, n ^m path monitoring cells are concentrated at the detection point m steps away from the generation point.

As a result, at the detection point having a large number of stages from the generation point, when the traffic amount increases, a congestion state occurs and the traffic cell must be discarded.

[0051]

As described above, in the conventional multiplex path monitoring device, the path monitoring cells are terminated only at the final detection point, so that the same path monitoring cells are concentrated. There is a problem that the traffic cell may have to be discarded due to the congestion caused by.

Therefore, it is an object of the present invention to provide a multiplex path monitoring device capable of avoiding the discarding of traffic cells due to the concentration of path monitoring cells.

[0053]

FIG. 1 is a diagram for explaining the principle configuration of the invention according to claim 1. In FIG.

In the figure, reference numeral 21 is a path monitoring information generating means provided at a point A where the path monitoring information is generated. The path monitoring information generating means 21 is adapted to generate path monitoring information including identification information indicating a source redundant system of the path monitoring information.

Reference numeral 22 is a first normality judging means provided at the intermediate detection point B of the path monitoring information. The first normality judging means 22 judges whether or not the path is normal based on the detected path monitoring information.

Reference numeral 23 is also a first path monitoring information terminating means provided at the intermediate detection point B. Based on the identification information included in the detected path monitoring information, the first path monitoring information terminating means 23 determines whether or not the own system and the source redundant system of the path monitoring information match, and if they do not match. Terminates the detected path monitoring information.

Reference numeral 24 is a second normality judging means provided at the final detection point C of the path monitoring information. The second normality judging means 24 judges whether or not the path is normal based on the detected path monitoring information.

25 is also a second path monitoring information terminating means provided at the final detection point C and terminating the detected path monitoring information.

[0059]

According to the above configuration, the path monitoring information including the identification information indicating the source redundant system is output from the generation point A of the path monitoring information.

At the intermediate detection point B of the path monitoring information,
Based on the identification information included in the detected path monitoring information,
It is determined whether or not the own system matches the generation redundant system.

As a result of this judgment, if the systems do not match, the path monitoring information is terminated, and if they match, they are not terminated.

Furthermore, at the final detection point C of the path monitoring information, the detected path monitoring information is always terminated.

By the above operation, the detection points B and C are
Only one path monitoring information is supplied at any one time. As a result, it is possible to avoid cell discard due to concentration of path monitoring information.

[0064]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of the path monitor cell generator in the path monitor according to the embodiment of the present invention.

As shown in the figure, the path supervisory cell generator of this embodiment is constructed by adding an identification information insertion circuit 214 to the conventional path supervisory cell generator shown in FIG. Therefore, in FIG. 2, the same parts as those in FIG.

The identification information insertion circuit 214 inserts identification information indicating the source redundant system of the path monitoring cell into the path monitoring data.

The identification information insertion circuit 214 is, for example,
It is provided in the preceding stage of the latch circuits 211 and 212, and the identification information is inserted into the path monitoring data before the path monitoring data is supplied to the latch circuits 211 and 212.

According to this structure, when an empty cell is detected by the empty cell detection circuit 221, a path monitor cell containing the above identification information is inserted in the main signal path instead of the empty cell. ..

FIG. 3 is a diagram showing the format of the path monitor cell in this embodiment.

As shown, in this embodiment, "OAM".
The identification information is inserted by using the two bits D3 and D4 of the reserved bits D3 to D8 set after the. Here, “OAM” is an identifier indicating that the cell is a path monitoring cell.

FIG. 4 is a block diagram showing the configuration of a path supervisory cell detecting device which is provided at an intermediate detection point of the path supervisory cell and detects the path supervisory cell in the path supervisory device of this embodiment.

As shown in the figure, the path supervisory cell generator of this embodiment is constructed by adding a system determination circuit 34 to the conventional path supervisory cell detector shown in FIG. Therefore, in FIG. 4, the same parts as those in FIG. 11 are designated by the same reference numerals, and detailed description thereof will be omitted.

When the path monitor cell detection circuit 311 detects a path monitor cell, the system determination circuit 34 compares the identification information contained in this path monitor cell with the system data indicating its own system to generate a source redundancy. It is determined whether the system and the self system match.

When it is determined by this determination process that "mismatch" occurs, the empty cell generation circuit 331 generates an empty cell and the selector 332 selects the empty cell.

On the other hand, if it is determined as "match", the empty cell generation circuit 331 does not generate an empty cell, and the selector 332 selects the main signal.

Therefore, when the own system is not the source redundant system, the path monitoring cell is terminated.

At the final detection point, the path monitoring cell detection device shown in FIG. 12 is arranged as in the conventional case.

As a result, at this final detection point,
When a path monitor cell is detected, this path monitor cell is replaced with an empty cell and terminated.

The operation when the multiplex path monitoring device of this embodiment is applied to the multiplex path monitoring device of the cross-connect device having the above-mentioned duplex structure in the above configuration will be described.

FIG. 5 is a diagram showing the flow of cells when the "0" system is the source redundant system.

In this case, the path monitor cell generator of FIG. 2 is arranged at the generation point a, and the intermediate detection points b, c, d, f,
The path monitoring cell detection device of FIG. 4 is arranged in g and h,
At the final detection point e, the path monitoring cell detection device of FIG. 12 is arranged as in the conventional case.

In such a configuration, the path monitor cell including the identification information indicating the "0" system is output from the generation point a. This path monitoring cell is supplied to the intermediate detection points b and f.

In this case, since the intermediate detection point b is the "0" system, the determination result of the system determination circuit 34 at this intermediate detection b is "coincidence". As a result, at this intermediate detection point b,
The path monitoring cell is not terminated, and this path monitoring cell is directly supplied to the intermediate detection points c and g.

On the other hand, since the intermediate detection point f is a "1" system, the determination result of the system determination circuit 34 is "mismatch" at this intermediate detection point f. As a result, at this intermediate detection point f, the path monitoring cell is replaced with an empty cell, and this path monitoring cell is terminated.

The path monitor cell supplied to the intermediate detection point c is not terminated like the intermediate detection point b because the system of the intermediate detection c is the "0" system, and further, the intermediate detection points d and h. Is supplied to. On the other hand, the path monitor cell supplied to the intermediate detection point g is terminated similarly to the intermediate detection point f because the intermediate detection g is the "1" system.

The path monitor cell supplied to the intermediate detection point d is not terminated and is further supplied to the final detection point e because the system of the intermediate detection point d is "0" system. On the other hand, the path monitor cell supplied to the intermediate detection point h is terminated because the intermediate detection point h is the "1" system.

The path monitor cell supplied to the final detection point e is terminated as in the conventional case.

With the above processing, when the "0" system is to be the source redundant system, a → b, b → c, c → d, d → e, a
The normality of the path between → f, b → g and c → h is determined.

In this case, since the path monitoring cell is terminated at the intermediate detection points f, g, h whose system is different from the origin redundant system of the path monitoring cell, the respective detection points b, c, d, e, f, g, h
Is supplied with only one path monitoring cell.

As a result, even if the traffic volume increases, it is possible to avoid discarding traffic cells due to the concentration of path monitoring cells.

FIG. 6 is a diagram showing the flow of cells when the "1" system is used as the source redundant system.

In this case as well, although the detailed description is omitted, the normality of the plurality of paths described above is determined. This allows
Eventually, the normality of all paths will be judged.

Also, discarding of traffic cells is avoided for the same reason.

As described in detail above, according to this embodiment,
The identification information indicating the source redundant system is inserted in the path monitoring cell, and when the system at the intermediate detection point is different from the source redundant system, the path monitoring cell is terminated. It is possible to avoid discarding the traffic cells that are used.

The above effect can be obtained by adding a few circuits to the conventional path monitoring device.

In the above description, the case where the present invention is applied to the path monitoring of the transmission system having the multiplex number of 2 has been described. However, the present invention also applies to the path monitoring of the transmission system having the multiplex number of 3 or more. Can be applied.

In addition to this, it goes without saying that the present invention can be variously modified without departing from the scope of the invention.

[0099]

As described in detail above, according to the present invention,
It is possible to provide a multiplexed path monitoring device capable of avoiding the discarding of traffic cells due to the concentration of path monitoring cells.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an invention according to claim 1.

FIG. 2 is a block diagram showing a configuration of a path supervisory cell generating device in the multiplexed path supervisory device of the first embodiment.

FIG. 3 is a diagram showing a format of a path monitoring cell according to the first embodiment.

FIG. 4 is a block diagram of the multiplexed path monitoring device according to the first embodiment.
It is a block diagram showing a configuration of a path monitoring cell detection device provided at an intermediate detection point.

FIG. 5 is a diagram showing a cell route when a “0” system is used as a generation source redundant system in the first embodiment.

FIG. 6 is a diagram showing a cell route in the case where the “1” system is the generation source redundant system in the first embodiment.

FIG. 7 is a block diagram showing a path configuration of an ATM signal transfer cross-connect device having a duplex configuration.

FIG. 8 is a diagram showing a cell route in the case where a “0” system is used as a source redundant system in a conventional multiplexed path monitoring device.

FIG. 9 is a diagram showing a cell route in a case where a “1” system is used as a source redundant system in a conventional multiplexed path monitoring device.

FIG. 10 is a block diagram showing a configuration of a path monitoring cell generating device in a conventional multipath monitoring device.

FIG. 11 is a block diagram showing a configuration of a path monitoring cell detection device arranged at an intermediate detection point in a conventional multiplexed path monitoring device.

FIG. 12 is a block diagram showing a configuration of a path monitoring cell detection device arranged at a final detection point in a conventional multiplexed path monitoring device.

[Explanation of symbols]

21 path monitoring information generating means 22 first normality determining means 23 first path monitoring information terminating means 24 second normality determining means 25 second path monitoring information terminating means

Front page continuation (72) Inventor Kenji Akutsu 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (5)

[Claims] 1. A multiplexing system provided in a transmission system in which a main signal path is multiplexed between a plurality of redundant systems, and transmitting path monitoring information on the path to monitor whether the path is normal or not. And a path monitoring information generating means (21) which is provided at the generation point (A) of the path monitoring information, and which generates path monitoring information including identification information indicating a redundant system from which the path monitoring information is generated. A first normality determination means (22) provided at the intermediate detection point (B) of the path monitoring information and determining whether the path is normal based on the detected path monitoring information; and the intermediate detection point Provided in (B), based on the identification information included in the detected path monitoring information, it is determined whether or not the own system and the source redundant system match, and if they do not match,
A first path monitoring information terminating means (23) for terminating the detected path monitoring information, and a final detection point (C) of the path monitoring information, which determines whether or not the path is normal based on the detected path monitoring information. A second normality judging means (24) for judging whether or not there is provided, and a second path monitoring information terminating means (25) provided at the final detection point (C) and terminating the detected path monitoring information. A multiplexed path monitoring device characterized by the above. 2. The main signal is an asynchronous transfer mode signal, and the path monitoring information is configured to be transmitted during a vacant cell period of the asynchronous transfer mode signal. The described multiplexed path monitoring device. 3. A path monitoring information generating device, which is provided in a transmission system in which a main signal path is multiplexed between a plurality of redundant systems, and which generates path monitoring information for determining whether or not the path is normal. A path monitoring information generating device configured to generate path monitoring information including identification information indicating a redundant system from which the path monitoring information is generated. 4. A path monitoring information detecting device provided in a transmission system in which a main signal path is multiplexed between a plurality of redundant systems, and detecting path monitoring information for determining whether or not the path is normal. A normality determining unit (22) that receives path monitoring information including identification information indicating a source redundant system of the path monitoring information, and determines whether the path is normal based on the path monitoring information, Based on the identification information included in the path monitoring information,
The path monitoring information is characterized in that it determines whether or not the own system and the origin redundant system match, and if they do not match, it comprises path monitoring information termination means (23) for terminating the path monitoring information. Detection device. 5. A multiplexed path monitoring device provided in a transmission system in which a path of a main signal is multiplexed between a plurality of redundant systems and transmitting path monitoring information to monitor whether the path is normal or not. In the path monitoring information, the identification information indicating the origin redundant system is inserted, and at the intermediate detection point of the path monitoring information, the system of the intermediate detection point is the origin redundant system based on the identification information. The multiplexed path monitoring device is characterized in that it is configured to terminate the path monitoring information if it does not match.