JPH11154949A - Communication channel network fault diagnostic device and recording medium storing program readable by machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a diagnostic result for part of faults without database retrieval processing. SOLUTION: A fault diagnostic dictionary 102 stores in advance a cross-reference for each transmission channel, a fault signal 4 corresponding to the involved transmission channel and relation between each transmission channel of a highest layer of a communication channel network and subordinate transmission channels affected by the fault. On occurrence of the fault signal 4 in each point of the communication channel network, a time collection means 101 collects a series of fault signals within a prescribed collection time. A discrimination means 103 discriminates whether or not a series of the fault signals collected include fault signals registered in the fault diagnostic dictionary 102. In the case that the fault diagnostic dictionary 102 does not include the fault signals, a fault diagnostic means 105 diagnoses through retrieval of a database. When the fault signals are included in the dictionary, a highest rank transmission channel fault diagnostic means 104 generates a diagnostic result that the transmission channel of the highest layer registered in the fault diagnostic dictionary 102 corresponding to the fault signals is a major cause of the fault and its subordinate transmission channels are affected by the faults.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication network fault diagnosis apparatus for diagnosing a transmission path or the like which is the main cause of a fault based on fault signals generated at various points in a communication network.

[0002]

2. Description of the Related Art Conventionally, a line monitoring system using a database described in Japanese Patent Application Laid-Open No. 61-288648 (hereinafter referred to as a conventional device) has been known as this type of communication line network fault diagnosis device. I have.

FIG. 5 shows a block diagram of a conventional apparatus. The failure signal 4 sent from each monitored station 1 of the communication network to be diagnosed (monitored) is input to a computer 3 where the computer 3 performs processing 5 according to a database 8 reflecting the structure of the communication network. Is executed to generate a diagnostic output. The database 8 includes a signal transmission line set occurrence 12, which defines the correspondence between the failure signal 4 and the transmission line, the upper and lower hierarchical relationships when the transmission line is vertically divided into arbitrary sections, and the transmission path is divided into sections. In this case, the transmission path set occurrence 13 defining the horizontal communication relationship is included. In the process 5, the signal transmission path set occurrence 12 is searched from the failure signal 4 to determine the transmission path corresponding to the failure signal. The transmission path set occurrence 13 is searched from the result of the determination, and a diagnosis result indicating the transmission path that is the main cause of the failure and the transmission path affected by the failure is generated.

FIG. 6 shows an example of a communication line network to be diagnosed.
FIG. 7 shows an example of the data structure of the database 8 reflecting the structure of the communication network shown in FIG.

In the communication network shown in FIG. 6, stations A to D are set as monitored stations 1, and propagation paths 2 connecting these monitored stations 1 are provided.
The carrier B and carrier C of the micro-system radio propagation path between the stations B and the stations A and C, the carrier A of the cable carrier system propagation path between the stations A and C, and the digital multiplexing between the stations B and D. The transport D of the system optical cable propagation path is set respectively. Also, SG
MUX, GMUX, and CHMUX indicate an SG band multiplexing function unit, a G band multiplexing function unit, and a CH band demultiplexing function unit of the carrier terminal equipment, respectively, and TRF is a two-routed station A and station C.
TR indicates a microwave transmission / reception device. Further, a small circle point indicates a failure detection point, and indicates that a failure signal 4 is input to the computer 3 from this point. A block indicated by a dotted arrow indicates the contents of a series of failure signals 4 input to the computer 3. Show. Also,
Time X is the failure signal 4 in the CH band, GX is the failure signal 4 in the G band,
The section X indicates the fault signal 4 of the propagation path 2. Carry X is propagation path 2,
The path X is a transmission path using the G band, and CHX is a transmission path using the tone CH band, through which a user transmission path passes, for example, CH1.
Is a transmission line between the CHMUX of the station A and the CHMUX of the station C, YX is a user transmission line exclusively used by the terminal device as a user of the transmission line, line X is a terminal device of the line,
For example, the user transmission line “U E” is the terminal device “Line E” of the station D.
Is connected to

The definition of a database corresponding to such a communication network is performed, for example, as follows. 1) User transmission line; the terminal device (line X) is connected to the user transmission line (YX). 2) CH transmission path; CH transmission path "CH1"
1 ”and“ YuA ”, and“ CH2 ”is“ YuB2 ”,
"Yu C" passes. 3) G transmission path: "CH1" passes through the G transmission path "path A", and "CH2" and "YU" pass through "path C". 4) Propagation path: "Path A" passes through the propagation path "Transport A", "Path C" passes through "Transport B" and "Transport C", and "U E" passes through "Transport D". . 5) Monitoring signal; "District A" of the monitoring signal 4 relates to "Transport A", "District B1" and "District B2" relate to "Transport B", and similarly, relations of other "District X". There is. In addition, “G
“A” is “Road A”, “GC” is “Road C”, “District A” is “YuA”, “Time B” is “YuB1”, “YuB2”,
“Time E” is related to “You E”. 6) Stations: "Station A" includes "Time A", "Time B", "Time E", "GA", "Distance A1", and "Distance B1" of the monitoring signal 4, and is located at "Distance B". Are “ward B2”, “ward D1”, “ward C
1 "," station C "includes" ward C2 "," GC "," ward A2 ", and" time C ", and" station D "includes" ward D2 ". 7) Schema: The schema is composed of “station A”, “station B”, “station C”, and “station D”. 8) 2 route lines; "Y B1" and "Y B2" are "Line B"
2 route line.

The database structure shown in FIG. 7 is constructed in accordance with the above database definition. In FIG. 7, the large circles indicate the schema 14 and record occurrences (10, 11, 15), and the small circles passing through the solid lines indicate the signal. The transmission line set occurrence 12, the solid line is the transmission line set occurrence 13, the single bar crossing the solid line is the schema station set occurrence 16, and the double bar crossing the solid line is the station signal set occurrence. The transmission line record occurrence 11 located at the top of the figure has a higher priority and the one located at the bottom has a lower priority.

FIG. 8 is a flowchart showing a processing example of the conventional apparatus. Hereinafter, the places marked with stars in FIG.
That is, the reception carrier of the microwave transmission / reception device in the section is cut off due to extremely strong fading on the carrier B of the propagation path 2, and a failure signal 4 in a hatched portion in FIG. The operation of the conventional apparatus will be described by taking the case as an example.

First, the fault signal is mapped to the database 8 to obtain the sections B1, B2, GC, times B, times E (hatched portions in FIG. 8) in the signal record occurrences 10 of the database 8 (FIG. 8). S11). Next, a transmission line record occurrence 11 correlated with each of the signal record occurrences 10 is searched for along the signal transmission line set occurrence 12 (on the arrow in FIG. 7), and To obtain the transmission line record occurrence 11 (transportation B, path C, user B1, user B2, user E) (S12) and store them in the temporary storage M1 (S1).
3).

Next, each transmission line record occurrence 11
, A delivery B located at a higher hierarchical level is extracted and temporarily stored M
2 (S14). Then, the transmission line set occurrence 13 is traced from the transport B of the record occurrence 11 to the lower hierarchy (on the arrow in FIG. 7), and the transmission line record occurrence 11 (path C, U B2, line B) is traced. A search is made (S15), these are transferred to the temporary storage M3, and the same is deleted from the temporary storage M1 (S16, S17). When the line B of the transmission line record occurrence 11 is reached, the line has reached the lowest level of the database (S18).
YES), backtrack to the transport B of the transmission path record occurrence 11 (S20), and continue the search from the transport B by tracing the transmission path set occurrence 13 different from the previous time,
The transmission line record occurrence 11 (U, line E) is obtained. Here, similarly, these are transferred to the temporary storage M3 and the same is deleted from the temporary storage M1. Furthermore, since the line E of the transmission line record occurrence 11 has reached the lowest level of the database 8, the backtracking is performed to the transmission line B of the transmission line record occurrence 1, and these operations are performed on the transmission line to be traced from the transmission B. The process is continued until the set occurrence 13 disappears (S19). Then, when all of them have been traced, the transmission line record occurrence 11 stored in the temporary storage M2 is affected by the transmission line record occurrence 11 stored in the temporary storage M3. The diagnosis result for the road is output (S21). If there is a transmission line record occurrence left in the temporary storage M1, it is output as other information.

[0011]

According to the above-mentioned prior art, even if a change occurs in the equipment to be monitored, the effectiveness of the diagnostic function can be maintained by changing the database. However, the database search process is generally a high-load process. In the conventional apparatus, such a high-load database search process must be performed in order to perform a diagnosis, and thus there is a problem that the load of the diagnosis process increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for obtaining a diagnosis result for some failures without database search processing, thereby suppressing an increase in the load of the diagnosis processing.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a communication network fault diagnosis apparatus for performing fault diagnosis based on fault signals generated at various points in a communication network. A failure diagnosis dictionary in which the correspondence between the transmission path, the failure signal corresponding to the transmission path and the lower transmission path affected by the failure of the transmission path is registered in advance, Determining means for determining whether a series of fault signals generated from the communication network include a fault signal registered in the fault diagnosis dictionary; and a fault determined to be included by the determining means. A top-level transmission path fault that generates a diagnosis result with the top-level transmission path registered in the failure diagnosis dictionary corresponding to the signal as the main cause of the failure and the lower-level transmission path as the transmission path affected by the failure Diagnostic means There.

[0014] In the communication network fault diagnosis apparatus of the present invention configured as described above, the fault diagnosis dictionary corresponds to the transmission path and the transmission path for each transmission path of the highest hierarchy of the communication network. The correspondence relationship between the failure signal to be generated and the lower transmission path affected by the failure of the transmission path is held in advance, and when a failure signal is generated at various points in the communication network, the determination means generates a series of generated failure signals. It is determined whether or not a failure signal registered in the failure diagnosis dictionary is included.If the failure signal is included in the failure diagnosis dictionary, the highest-level transmission path failure diagnosis means stores the failure signal in the failure diagnosis dictionary in accordance with the failure signal. A diagnostic result is generated in which the registered transmission line of the highest hierarchy is the main cause of the failure and the lower transmission line is the transmission line affected by the failure.

Further, the present invention achieves the above objects,
Communication that performs fault diagnosis based on fault signals that occur at various points in a communication network in order to eliminate the effects of fault signal propagation delay and the like and to prevent redundant diagnostic processing due to fault signals that occur repeatedly in a relatively short time. In the network fault diagnosis apparatus, for each transmission line in the highest hierarchy of the communication network, the correspondence between the transmission line, a failure signal corresponding to the transmission line, and a lower transmission line affected by the failure of the transmission line. A failure diagnosis dictionary registered in advance, a time aggregation unit that aggregates a series of failure signals generated from the communication network within an aggregation time of a predetermined time, and a series of failure signals aggregated by the time aggregation unit. Determining means for determining whether or not a failure signal registered in the failure diagnosis dictionary is included; and in the failure diagnosis dictionary corresponding to the failure signal determined to be included by the determination means. The main cause of failure of the transmission line of the uppermost hierarchy is recorded, and a top-level transmission line fault diagnosis means for generating a diagnosis result the lower transmission line and a transmission line affected by the fault.

In the communication network fault diagnosis apparatus thus constructed, the fault diagnosis dictionary stores, for each transmission path in the highest hierarchy of the communication network, a transmission path and a failure signal corresponding to the transmission path. And a lower-level transmission line affected by the failure of the transmission line in advance, and when a failure signal is generated in various parts of the communication network, the time aggregation means causes a series of generated failure signals to be generated for a certain period of time. And the determination means determines whether or not the series of failure signals subjected to the aggregation processing include failure signals registered in the failure diagnosis dictionary. Then, when the failure signal registered in the failure diagnosis dictionary is included, the highest-level transmission path failure diagnosis means determines the highest-level transmission path registered in the failure diagnosis dictionary corresponding to the failure signal. A diagnosis result is generated in which the main cause of the failure and the lower transmission line are set as transmission lines affected by the failure.

Further, the present invention provides a signal transmission line set occurrence which defines a correspondence relationship between a fault signal and a transmission line, and a hierarchical relationship above and below the transmission line when a transmission line is vertically divided into arbitrary sections and a transmission line. And a transmission path set occurrence that defines a horizontal communication relationship in the case of dividing into a plurality of failure signals, and a failure signal registered in the failure diagnosis dictionary in a series of failure signals generated from the communication network. Is not included, the signal transmission path set occurrence is searched for from the failure signal to determine the transmission path corresponding to the failure signal, and further the transmission path set occurrence is determined from the determination result. Fault diagnosis means for searching a reference and generating a diagnosis result by a database search.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention. The communication network fault diagnosis apparatus 100 of the present embodiment receives and analyzes a fault signal 4 transmitted from each monitored station 1 of the communication network, and analyzes a diagnosis result of a transmission path or the like which is a main cause of the fault. The time aggregation means 101, the failure diagnosis dictionary 102, the determination means 103, the highest-order transmission path failure diagnosis means 1
04, a failure diagnosis means 105 by database search and an output means 106 are provided.

Such a communication line network fault diagnosis apparatus 100
Can be realized by the computer and the recording medium 200. That is, the recording medium 200 is a machine-readable recording medium such as a CD-ROM, a magnetic disk, and a semiconductor memory, and the program for diagnosing the communication network failure recorded therein constitutes the communication network failure diagnosis apparatus 100. By being read by the computer and controlling the operation of the computer, the time aggregation unit 101, the failure diagnosis dictionary 102, and the determination unit 10 shown in FIG.
Third, the highest-order transmission path failure diagnosis means 104, the failure diagnosis means 105 by database search, and the output means 106 are realized.

The time aggregating means 101 provides an aggregating time of a certain time, and outputs the failure signal 4 sent from each monitored station 1.
Are aggregated within the aggregation time. FIG. 2 is a diagram for explaining the operation of the time aggregation means 101. As shown at points a and b in FIG. 3, when a failure occurs in any of the communication network, the state of the failure signal 4 from the corresponding monitored station 1 changes from normal to failure occurrence. At this time, the transmission paths are configured in a hierarchical manner, and if a failure occurs in an upper transmission path, an influence failure occurs in the lower transmission path. Therefore, a failure signal from the monitored station 1 corresponding to the lower transmission path. 4 also changes. However, each monitored station 1 sends a communication network fault diagnosis device 1
Due to factors such as the difference in propagation delay up to 00, the state of the plurality of fault signals 4 does not always change at the same time, and the timing of the state change may be slightly shifted as shown in part a of FIG. Further, as shown in FIG. 2B, the failure signal 4 may repeat the failure state and the recovery state at relatively short time intervals due to fading or the like.

The time aggregating means 101 outputs all fault signals 4
If any of the fault signals 4 changes from normal to fault occurrence in a status indicating that the fault signal is normal, an aggregation time is set for a certain time from that point and the change in the status of the failure signal within the aggregation time is monitored. Then, a series of failure signals subjected to the aggregation processing are transmitted to the determination unit 103. Here, the state change is aggregated for each failure signal 4, and a failure signal indicating a failure state at least once within a certain period of time is determined as "failure occurred". At this point, the information is transmitted to the determination means 103 in a lump. Thereby, even if the timing of the state change of the series of failure signals 4 is shifted as shown in FIG. 2A, the state change timing can be made uniform, and a relatively short state as shown in FIG. 2B. Even when the failure signal 4 repeats the failure state and the recovery state at time intervals, they can be processed as one failure.

The failure diagnosis dictionary 102 stores, for each transmission line in the highest hierarchy of the communication network, a correspondence between the transmission line, a failure signal corresponding to the transmission line, and a lower transmission line affected by the failure of the transmission line. This is a dictionary in which relationships are registered in advance. For example, when the communication network is the one shown in FIG. 6, the transmission paths of the highest hierarchy are transport A, transport B, transport C, and transport D.
The above information is registered in advance for each D. Here, for example, when the transport B is considered, there are two failure signals corresponding to the transport B in the case of FIG. 6, “ward B1” and “ward B2”.
Since information such as “Route C” and “You E” can be predicted in advance, information as exemplified in FIG. Similar information is registered for the other deliveries A, C, and D.

The determination means 103 includes a failure diagnosis dictionary 102 in a series of failure signals transmitted from the time aggregation means 101.
It is determined whether the failure signal registered in is included,
If it is included, it passes the included fault signal to activate the top-level transmission path fault diagnostic means 104, and if it is not included, it passes a series of fault signals transmitted from the time aggregation means 101. To activate the failure diagnosis means 105 by database search.

The highest-level transmission path fault diagnosis means 104 determines the highest-level transmission path corresponding to the fault signal passed from the determination means 103 and the lower-level transmission paths affected by the fault of the transmission path from the fault diagnosis dictionary 102. This is a means for generating a diagnosis result in which the searched transmission line of the highest hierarchy is regarded as a transmission line which is a main cause of the failure, and the searched lower transmission line is regarded as a transmission line affected by the failure.

Failure diagnosis means 10 by database search
Reference numeral 5 denotes an existing fault diagnosis unit using the database described in the section of the prior art. This failure diagnosis means 105 can use the technology described in the above-mentioned Japanese Patent Application Laid-Open No. 61-288648.

The output unit 106 outputs the diagnosis result generated by the top-level transmission path failure diagnosis unit 104 or the failure diagnosis unit 105 based on a database search to an output device (not shown) such as a display device, a printing device, or a file device. It is.

FIG. 4 is a flowchart showing the processing flow of the communication network fault diagnosis apparatus 100. Hereinafter, the operation of this embodiment will be described with reference to the drawings.

When any one of the failure signals 4 from the monitored station 1 of the communication network changes from a normal state to a failure state, the time aggregation means 101 sets an aggregation time of a certain time from that time and sets the aggregation time. The state change of the failure signal within the group is aggregated, and a series of aggregated failure signals is transmitted to the determination unit 103 (S1 in FIG. 4).

The judging means 103 includes, in the series of fault signals transmitted from the time aggregating means 101,
It is determined whether or not a failure signal corresponding to the transmission path of the highest hierarchy registered in is registered (S2 in FIG. 4). Then, when a failure signal corresponding to the transmission path of the highest hierarchy is included, the failure signal is notified to activate the highest transmission path failure diagnosis means 104, and conversely, such a failure signal is included. If not, a series of failure signals transmitted from the time aggregation means 101 are notified to activate the failure diagnosis means 105 by database search.

When activated, the highest-order transmission line fault diagnosis means 104 starts the fault diagnosis dictionary 10 by using the notified fault signal as a key.
2 is searched, and the highest-order transmission path registered corresponding to the failure signal is determined as the main transmission path of the failure, and the lower transmission path registered corresponding to the failure signal is determined as the influence of the failure. A diagnostic result as a transmission path to be received is generated and output means 10
6 (S3 in FIG. 4). Since no database search is involved, this processing can be executed with a light load.

On the other hand, when the failure diagnosing means 105 based on the database search is activated, it performs a database search process to generate a diagnosis result as described in the section of the prior art, and
Output to the output means 106 (S4 in FIG. 4).

The output means 106 outputs a diagnosis result output from the highest-order transmission path failure diagnosis means 104 or the failure diagnosis means 105 by database search to an output device (not shown) (S5 in FIG. 4).

Accordingly, as shown by the star in FIG. 6, a failure occurs in the transport B, and the “ward B1” and the “ward B” shown in FIG.
When the state of a series of failure signals including "2" changes to "occurrence of failure", "diagnosis B1" and "division B2" registered in the failure diagnosis dictionary of FIG. Failure diagnosis is performed using the dictionary, and as a result, a diagnosis result is output with the transport B as the main cause transmission path and the paths C, E and the like as the affected transmission paths.

The method of using the affected transmission line included in the diagnosis result is to mask the transmission line determined as the affected transmission line in the diagnosis result among the lower transmission lines from which the failure signal is output, and Otherwise, there is a usage method that notifies the system administrator or the like.

[0036]

As described above, according to the present invention, the following effects can be obtained.

For a failure in the transmission line of the highest hierarchy, a diagnosis result can be obtained without database search processing, and an increase in the load of the diagnosis processing can be suppressed accordingly. The reason is that, for each transmission line in the highest layer of the communication network, the correspondence between the transmission line, the failure signal corresponding to the transmission line, and the lower transmission line affected by the failure of the transmission line is diagnosed in advance. If a series of fault signals registered in the dictionary and included in the fault diagnosis dictionary are included in a series of fault signals generated at various points in the communication network, the highest-level transmission path fault diagnosis means will detect the fault. This is because a diagnosis result is generated in which the transmission path of the highest hierarchy registered in the failure diagnosis dictionary corresponding to the signal is the main cause of the failure and the lower transmission path is the transmission path affected by the failure.

The influence of the propagation delay of the fault signal can be eliminated.
Further, it is possible to prevent a redundant diagnosis process due to a failure signal repeatedly generated in a relatively short time. The reason is that a series of failure signals generated in various parts of the communication network are temporally aggregated by the time aggregation means.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation of a time aggregation unit.

FIG. 3 is an explanatory diagram of the contents of a failure diagnosis dictionary.

FIG. 4 is a flowchart showing a processing flow of the communication line network fault diagnosis device.

FIG. 5 is a block diagram of a conventional device.

FIG. 6 is a diagram illustrating an example of a communication network to be diagnosed.

FIG. 7 is a diagram showing an example of a data structure of a database reflecting the structure of the communication network of FIG. 6;

FIG. 8 is a flowchart illustrating a processing example of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Monitored station 2 ... Propagation path 4 ... Failure signal 100 ... Communication line network failure diagnosis apparatus (computer) 101 ... Time aggregation means 102 ... Failure diagnosis dictionary 103 ... Judgment means 104 ... Top-level transmission path failure diagnosis means 105 ... Database Failure diagnosis means by search 106 ... output means 200 ... recording medium

Claims (4)

[Claims] An apparatus for diagnosing a failure in a communication network based on a failure signal generated in each part of the communication network, comprising: A fault diagnosis dictionary in which the correspondence between the fault signal corresponding to the path and the lower transmission path affected by the fault of the transmission path is registered in advance, and the fault diagnosis is performed in a series of fault signals generated from the communication network. Determining means for determining whether or not the failure signal registered in the dictionary is included; and the highest level registered in the failure diagnosis dictionary corresponding to the failure signal determined to be included by the determination means A communication line network fault diagnosis device, comprising: a highest level transmission line fault diagnosis means for generating a diagnosis result in which a transmission line in a hierarchy is a main cause of a fault and a lower transmission line is a transmission line affected by the fault. . 2. A communication network fault diagnosis apparatus for performing a fault diagnosis based on a fault signal generated at various points in a communication network, comprising: A fault diagnosis dictionary in which the correspondence between the fault signal corresponding to the path and the lower transmission path affected by the fault in the transmission path is registered in advance, and a series of fault signals generated from the communication line network are collected for a certain period of time. Within a series of failure signals aggregated by the time aggregation means,
Determining means for determining whether a failure signal registered in the failure diagnosis dictionary is included; and registering in the failure diagnosis dictionary corresponding to the failure signal determined to be included by the determination means. A communication line network for generating a diagnosis result in which a transmission line of the highest hierarchy is a main cause of the failure and a lower transmission line is a transmission line affected by the failure. Failure diagnosis device. 3. A signal transmission line set occurrence that defines a correspondence between a failure signal and a transmission line, a hierarchical relationship between the upper and lower hierarchies when the transmission line is vertically divided into arbitrary sections, and the transmission path is divided into sections. And a transmission path set occurrence that defines a horizontal communication relationship in the case where the communication path network includes a failure signal registered in the failure diagnosis dictionary in a series of failure signals generated from the communication line network. When it is determined by the determination means that there is no transmission path set occurrence from the failure signal, the transmission path corresponding to the failure signal is determined, and further, the transmission path set occurrence is searched from the determination result. 3. The communication network fault diagnosis apparatus according to claim 1, further comprising a fault diagnosis unit that searches a database to generate a diagnosis result. 4. A computer constituting a communication network fault diagnosis apparatus for performing a fault diagnosis based on a fault signal generated at various points in a communication network, wherein the computer is provided for each transmission line of the highest hierarchy of the communication network. A fault diagnosis dictionary in which the correspondence between the fault signal corresponding to the transmission path and the transmission path and the lower transmission path affected by the failure of the transmission path is registered in advance, and a series of failure signals generated from the communication network are stored for a predetermined time. Time aggregating means for aggregating within the aggregating time of
Determining means for determining whether a failure signal registered in the failure diagnosis dictionary is included; registered in the failure diagnosis dictionary corresponding to the failure signal determined to be included by the determination means A machine readable recording of a program for functioning as a transmission line failure diagnosis means for generating a diagnosis result in which a transmission line of the highest hierarchy is a main cause of a failure and a lower transmission line is a transmission line affected by the failure. recoding media.