JP2000013374A - Monitor for network state - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitor for a network state that collects fault notices informed from a network and informs a network manager of it efficiently so as to facilitate the maintenance by the network manager. SOLUTION: A consolidated link layer management CLLM message that is produced to send fault occurrence and restoration notices detected by each of frame exchanges 111=11N in a frame relay network 10 into the network is monitored by 1st to Nth probes 131-13N everywhere in the network 10. Then a manager 14 collects faults or congestion, their location and fault recovery states in the network based on the CLLM messages detected by each of the probes 131-13N so as to allow the network manager to countermeasure the fault quickly. Then the maintainability of the network is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a network condition monitoring device, and more particularly, to a network condition monitoring device for detecting and notifying a failure in a network.

[0002]

2. Description of the Related Art Frame relay technology simplifies packet switching technology, omits retransmission control caused by transmission errors and the like, and allows open systems interconnection.
connection: OSI) is a communication technology that performs high-speed transfer in frame units at the data link layer (second layer) level of the reference model. In particular, local area networks (Lo
cal Area Network (LAN) is used for communication services suitable for connection between LANs.

[0003] In recent years, the physical reliability of communication lines has been improved and transmission errors have been reduced, so that it is possible to omit transmission technology retransmission control in some communication applications. Therefore, it is convenient to improve the data transmission processing speed in the network while omitting the retransmission control, for example, the Internet (theI
Internet) has been built using such frame relay technology. As a result, a high-speed and low-delay amount like a network dedicated line is used, and an optimal communication service can be applied by divided transfer such as packet switching.

As described above, the Internet has realized a large-capacity data communication network among a large number of users by using a frame relay network. On the other hand,
As traffic in the network increases, congestion may occur and it may not be possible to provide a sufficient communication service. Therefore, measures for increasing traffic are an important issue for the network management side.

[0005] However, hitherto, traffic monitored by a switch of a frame relay network constructing the Internet has been totaled by a network state monitoring device and processed as statistical data. The network administrator has used the processed statistical data to identify the time or data link at which traffic increases, and has taken optimal measures for increasing traffic.

[0006]

As described above, in the conventional network condition monitoring apparatus, only the traffic in the network is monitored.
The failure notification from failure or congestion issued from within the frame relay network is not monitored. That is, the traffic in the monitored network is only processed as statistical data, and the network state monitoring device does not take any countermeasures against failure or congestion. The failure or congestion notification issued in the frame relay network is processed by the end user on the data transmission / reception side, and each device takes measures against the failure determined.

However, as the number of users in the network increases, it is desirable for the network administrator to take immediate measures against a failure that has occurred in the network. For example, by taking urgent measures for failures that can only be performed by the network management side, such as adding a new switch or adding a data link, it is possible to eliminate chronically occurring failures and provide more advanced communication services. Becomes possible.

Since the conventional network condition monitoring device only monitors communication traffic, if the data throughput of the frame relay network is reduced, the data communication volume itself is reduced, or the frame relay network for constructing the Internet. However, it was impossible to distinguish whether the communication transmission processing speed was temporarily reduced due to congestion or the data communication amount was reduced due to a failure. Also, for users of the frame relay network that constructs the Internet, if monitoring only communication traffic with the network condition monitoring device reduces the data throughput of the frame relay network, does the number of network users decrease due to the decrease in data throughput? Or due to congestion or failure in the frame relay network.

Therefore, even if the occurrence of a failure is notified from the frame relay network, the conventional network condition monitoring device monitors only the communication traffic. However, there is a problem that the execution of various trouble measures such as a request of a network administrator for trouble recovery measures is delayed. Further, even if the occurrence of congestion is notified from the frame relay network, the network state monitoring device monitors only the communication traffic, so that various congestion countermeasures such as requesting the transmission source to retransmit are taken. There was a problem of being late. As described above, the delay in the implementation of various failure countermeasures has led to a significant decrease in maintainability of frame relay network management.

It is an object of the present invention to provide a network status monitoring apparatus which collects fault occurrence notifications notified from a network and notifies the network efficiently, thereby facilitating maintenance of a network administrator. .

[0011]

According to the first aspect of the present invention, there is provided (a) a message detection for detecting a message in a network including a communication state of a data link in a network from communication data flowing through an arbitrary data link in the network. Means; (b) message extracting means for extracting a communication state of the data link included in the message detected by the message detecting means; and (c) communication state of the data link extracted by the message extracting means. And a message collecting means for collecting the information.

In other words, according to the first aspect of the present invention, a message in a network including a communication state of a data link in the network transmitted in the network is detected by message detection means from communication data flowing through an arbitrary data link. The message collecting means collects the communication states transmitted from the switching means at various places in the network.

[0013] According to the second aspect of the present invention, (a) from a communication data flowing through an arbitrary data link in the network, a failure state of the data link in the network or a failure state due to congestion and a data link which has detected the failure state are specified. Message detecting means for detecting an in-network message including link information to be transmitted; and (b) extracting a fault occurrence state due to a data link failure or congestion contained in the message detected by the message detecting means and the link information. The network condition monitoring device includes a message extracting unit and (c) a message collecting unit that collects, as failure occurrence information, a failure occurrence state of the data link and the link information extracted by the message extracting unit.

That is, according to the second aspect of the present invention, an in-network message transmitted within the network and including a state of occurrence of a failure due to a data link failure or congestion in the network and link information for specifying a location of the failure is transmitted to the network. It is detected by message detection means from communication data flowing through an arbitrary data link.
Then, the state of such a failure occurrence transmitted from each place in the network is collected by the message collecting means.

According to the third aspect of the present invention, (a) the state of the occurrence of the failure due to the failure or congestion of the data link in the network and the data link which has detected the occurrence are specified from the communication data flowing through an arbitrary data link in the network. Message detecting means for detecting an in-network message including link information to be transmitted; and (b) extracting a fault occurrence state due to a data link failure or congestion contained in the message detected by the message detecting means and the link information. Message extracting means; (c) fault occurrence information holding means for holding the fault occurrence state extracted by the message extracting means and the link information; and (d) fault occurrence information held in the fault occurrence information holding means. If the occurrence of this fault is not detected after a predetermined time has passed since the Recovery notification means for notifying failure recovery, and (e) failure occurrence information and the link information extracted by the message extraction means and the link information, and failure recovery notification notified by the recovery notification means to failure occurrence information. And a message collecting means for collecting the message as a message.

That is, according to the third aspect of the present invention, a network message transmitted in the network and including a state of occurrence of a failure due to a data link failure or congestion in the network and link information for specifying the location of the failure is transmitted to the network. It is detected by message detection means from communication data flowing through an arbitrary data link.
Then, the state of such a failure occurrence is collected by the message collecting means. Further, the failure occurrence information holding means extracted from the message detected in the network holds the information, and if the same failure is not detected after a predetermined time has elapsed, it is determined that the failure has been recovered, and a further recovery notification is issued. I have. This recovery notification is also collected as failure occurrence information, similarly to the occurrence notification.

According to a fourth aspect of the present invention, in the network condition monitoring apparatus according to the second or third aspect, occurrence of a failure or its recovery is notified to the outside based on the failure occurrence information collected by the message collecting means. It is characterized by having external notification means.

That is, the invention according to claim 4 is provided with an external notifying means, and notifies the occurrence or restoration of a failure to the outside based on the failure occurrence information collected by the message collecting means.

According to a fifth aspect of the present invention, in the network condition monitoring apparatus of the first to fourth aspects, the network is a frame relay network, and the message is an integrated link layer management message.

That is, according to the fifth aspect of the present invention, the occurrence of a failure in the network transmitted from the frame relay network by the integrated link layer management message is detected.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments.

FIG. 1 shows an outline of a configuration of a network condition monitoring apparatus according to an embodiment of the present invention. This network condition monitoring device includes a frame relay network 10. Frame relay network 10 is provided with a plurality of the frame relay switch to (SW) 11 ₁ ~11 _M, it is possible to provide a switching service by the frame relay technology. These SW11 ₁ to 11 _M, in addition to the normal frame exchange, the occurrence of a failure or congestion data link connected respectively to monitor, so it is possible to perform a particular notification and its occurrence place of occurrence ing. The network condition monitoring apparatus according to the present embodiment collects the failure occurrence notifications generated by these SWs 11 _{1 to} 11 _M and performs efficient network management.

Each of the frame relay networks 10 includes
Frame relay line 12₁, 12_Two, ..., 12_NThrough
And the first probe 13₁, The second probe 13_Two, ...
-Nth probe 13_NIs connected. These first
~ Nth probe 13₁~ 13 _NIs the frame relay network 1
An observation point for monitoring the network condition at any point within 0
The monitoring information as the observation result of each probe is
It is collected in the jar 14. Manager 1
4 is a network management based on the collected monitoring information.
Notifying the administrator of the failure by displaying it on the screen
Is available. In the following, SW11₁~ 1
1_MHave the same configuration, and the first to Nth probes
13₁~ 13_NHave the same configuration.

In the frame relay network 10, communication data in the following frame format flows.
The communication data includes not only communication data transmitted and received between normal end users but also notification of occurrence of a failure or congestion in the frame relay network 10 detected by each of the SWs 11 _{1 to} 11 _M and specific information of the location of the occurrence. Consolidated Link Layer Management (hereinafter abbreviated as CLLM) messages also flow in the network.

FIG. 2 shows an outline of the configuration of such a frame format. The frame format 15 includes an address field 17, an information field 18, and a frame check sequence (hereinafter, FCS) between a plurality of flag data 16.
Abbreviated. ) 19 are inserted. That is, the flag data 16 is normally transmitted, and only when used for communication information, a frame in which data consisting of the address field 17 and below is inserted is transmitted. Assuming that the flag data 16 is 8-bit "01111110" data, the receiving side of this frame may synchronize with the 8-bit data "01111110". In the address field 17, information for identifying a data link is inserted.
The communication information corresponding to the data link identified by 7 is inserted into the information field 18. The FCS 19 is a code for error control detection of a plurality of pairs of information 20 including the address field 17 and the information field 18 identified thereby.

The address field 17 is 2 bytes long and has a data link connection identifier (Data Link Co.).
nnection Identifier: Hereinafter, abbreviated as DLCI. ) Are divided into an upper DLCI value 21 and a lower DLCI value 22. Extended Address File
ld: Hereinafter, abbreviated as EA. Bits 23 and 24 are 1-bit long, and when "0", indicate that the next byte string is also followed by the address field, and when "1", indicate the end of the byte string of the address field. here,
Since the address field 17 is 2 bytes long,
The EA bit 23 becomes "0" and the EA bit 24 becomes "1".

Further, on the lower side of the address field 17, a forward explicit congestion notification (Forward Explicit Congest
ion Notification: Hereinafter, abbreviated as FECN. ) Bit 2
5 and the backward explicit congestion notification (Backward Explicit Cong
estion Notification: Hereinafter, abbreviated as BECN. ) Bit 26. The FECN bit 25 is used when a transmission frame is congested in the frame relay network 10.
By setting "1", the occurrence of congestion of the transmission frame is notified to the receiving side. The BECN bit 26 is set to “1” when the received frame is congested in the frame relay network 10 to notify the receiving side of the occurrence of congestion of the received frame. On the receiving side,
Using the FECN bit 25 and the BECN bit 26, various types of congestion control such as lowering the transmission band or prompting the transmitting side to retransmit from the receiving side are performed. Discard Eligibility indicator (DE)
Bit 27 indicates whether the frame can be discarded in the network when network congestion occurs.

For such a frame format,
The above-mentioned CLLM message is stored in the address field 17.
Is identified as a CLLM message and flows through the frame relay network 10 by being inserted into the information field 18.

FIG. 3 shows an outline of the configuration of the CLLM message format. This as CLLM message, status information of the network, such as a fault or congestion of the frame relay network 10 is generated by each SW11 ₁ to 11 _M, it is inserted into the frame format of the information field 18 shown in FIG. The CLLM message 30 is
From the first octet, a parameter identifier, a parameter length, and information for the parameter length specified by the parameter identifier are inserted in order. As a CLLM message, at the time of failure notification of the frame relay network 10,
A reason display value indicating the type of the fault that has occurred and a DLCI value indicating a data link as a location where the fault has occurred are notified. Therefore, for example, by referring to the parameter identifier of the fourteenth octet, the reason indication value of one octet length of the parameter length of the fifteenth octet becomes the first.
It will be stored in 6 octets. Also, the first
By referring to the parameter identifier of 7 octets, it can be recognized that the DLCI value of 2 octets of the parameter length of the 18th octet is stored in the 19th and 20th octets. In the FCS 31, a transmission error detection code of the CLLM message after the first octet is inserted.

As described above, in such a CLLM message, each data link is constantly monitored by each of the SWs 11 _{1 to} 11 _M , and the status information in the frame relay network 10 as a result of the monitoring is incorporated into the frame format. , Will be transmitted within the network.

[0032] Figure 4 is a view showing a main part of such SW11 ₁ configuration. SW11 ₁ includes a failure detector 41 for detecting a fault occurring in the data link in the network, CLLM message assembled CLLM message shown in FIG. 3 to notify the fault detection result detected by the failure detecting unit 41 generates And a part 42.

The fault detecting unit 41 identifies the type of fault caused by congestion occurring in the network, device failure, or discarding all frames due to network maintenance, and detects this as a fault or occurrence of congestion. I can do it. The failure or congestion detected by the failure detecting unit 41 is notified by the CLLM message generating unit 42 using the reason display value corresponding to the detected failure and the DLCI number of the detected failed link as notification information in FIG.
And is transmitted into the frame relay network 10.

In this manner, the CLLM message transmitted in the frame relay network 10 is monitored, and the failure detected in the network is identified by monitoring the traffic of the exchanges or nodes throughout the network. The first to Nth probes 13 _{1 to} 13 _N are managers that collect monitoring information from each of the probes and notify the network administrator. Hereinafter, a description will be given of a first probe 13 ₁ and manager 14.

[0035] FIG. 5 is a view showing a main portion of the first probe 13 ₁ of the configuration. This first probe 13
Reference numeral ₁ denotes a frame monitoring unit 43 for monitoring frames flowing in the frame relay network 10, a manager notification unit 44 for notifying the manager 14 of a result monitored by the frame monitoring unit 43, and a monitoring process by the frame monitoring unit 43. And a timer 46 for determining failure recovery in the monitoring process of the frame monitoring unit 43. The first probe 13 ₁ monitors the CLLM message through the frame relay network 10. In the frame monitoring unit 43 detects a fault in the SW11 ₁ to 11 _M of the frame relay network 10. Then, when a CLLM message for notifying the occurrence of a failure is detected, the manager notifying unit 44 notifies the manager 14 of the type and location of the failure. On the other hand, in the first probe 13 within _1, detected failures and the failure detection notice time may be held at fault information holding unit 45, the failure detection notice time again the same failure after a predetermined time T has elapsed from the detection Recovery of the failure is detected based on whether or not the failure has occurred. When recovery from the failure is detected, the manager notification unit 44 again notifies the manager 14 of the recovery from the failure.

The first probe 13 ₁ to enable such control, a central processing unit (not shown) (Central Process
ing Unit: Hereinafter, abbreviated as CPU. ), And an external storage device such as a magnetic disk or a read-only memory (Read Only Memory:
Abbreviated as ROM. ), The monitoring process of the CLLM message and the notification process to the message 14 can be executed based on a program stored in a predetermined storage device.

FIG. 6 shows such a first probe 13 _1.
1 shows an outline of the CLLM message monitoring process and the notification process. The first probe 13 ₁ monitors various frames flowing in the frame relay network 10 and checks the DLCI number in the address field 17 (step S50), whereby each of the SWs 11 _{1 to} 11 in the frame relay network 10 is checked. CL generated by _M
The occurrence of a failure in the network can be recognized by the LM message (step S51). For example, as a CLLM message, the frame relay network 10
It is assumed that the DLCI number is "1007" in advance for a failure occurrence notification frame for notifying that a failure has occurred within the frame. Therefore, the DLCI number of the frame in the frame relay network 10 is checked, and when the number is "1007" (step S51: Y), it is recognized that a failure has occurred in the network. Then, from the reason display value of the CLLM message shown in FIG. 3, the type of a failure caused by congestion, equipment failure, or discarding of all frames due to network maintenance is extracted, and a failure is generated from the DLCI value shown in FIG. The information of the existing link is extracted (step S52).
The extracted information is stored in the timer 46 as the failure detection notification time.
The failure information is stored in the failure information storage unit 45 together with the measured time (step S53). Then, the manager notifying section 44 notifies the manager 14 of the fault information as a fault occurrence notification (step S54).

In step S51, the frame relay network 10
Check the DLCI number of the frame within the frame. If the number is not “1007” (step S51: N),
With reference to the failure information stored in the failure information storage unit 45, it is determined whether or not there is an unrecovered failure (step S55). When it is determined that there is an unrecovered failure (step S55: Y), it is further determined whether or not the elapsed time based on the failure detection notification time of the failure information is equal to or longer than a predetermined failure recovery detection time T. Is determined (step S56). When it is determined that the elapsed time is equal to or longer than the failure recovery detection time T (step S56: Y), no failure has been detected in the network, and it is determined that the failure has been recovered. Is notified to the manager 14 as a failure recovery notification (step S5).
7). On the other hand, when it is determined that the elapsed time does not exceed the failure recovery detection time T (step S56: N), or when it is determined in step S55 that there is no unrecovered failure by referring to the failure information (step S55). : N), the frame flowing in the frame relay network 10 is checked again.

By the way, the failure notification and the failure recovery notification that the manager notification unit 44 notifies the manager 14 are notified by the trap processing with the following information.

FIG. 7 shows an outline of the configuration of information notified by the manager notifying section 44. That is, the notification information 60 includes a probe identifier 61 previously assigned to each probe in order to identify the probe of the notification source.
And the CLLM shown in FIG. 3 in step S52 shown in FIG.
A failure type 62 caused by congestion, equipment failure, or all frame discarding due to network maintenance extracted from the reason display value of the message, and FIG.
Link information 63 for identifying the location where the failure has occurred, extracted from the DLCI value of the CLLM message indicated by
A notification time 64 as a time measured by the timer 46 is provided. The manager 14 that collects such notification information 60 from each probe facilitates the identification of the location of the occurrence of the failure, and improves the maintainability by managing the time of occurrence. Further, at the time of occurrence of a failure and at the time of recovery from the failure, the information is managed in a database together with the time of occurrence or recovery as management information as a failure occurrence history.

Next, the manager 14 that collects and manages such notification information will be described.

FIG. 8 shows a main part of the configuration of the manager 14. The manager 14 collects the notification information shown in FIG. 7 from each of the _first to Nth probes 13 _{1 to} 13 _{N, and} transmits the notification information collected by the probe information collection unit 70 to the network state management information. And a screen display unit 72 for notifying the network administrator of the network status based on the notification information collected by the probe information collection unit 70.
Such a manager 14 may be configured to control each of the probes 13 _{1 to} 13 _N
FIG. 6 shows a failure occurrence state of the frame relay network 10 in FIG.
Collected as the failure information indicated by. Then, it records in the database 71 as a history of a failure that has occurred in each data link or its recovery. In addition, each probe 13 ₁ -
From 13 _N each time generating or its failure recovery is notified, so that it can notify the network administrator performs screen display.

Manager 1 capable of performing such control
Reference numeral 4 denotes an external storage device such as a magnetic disk or an RO provided separately from the CPU.
Based on a program stored in a predetermined storage device such as M, the above-described failure occurrence history registration processing and screen display processing can be executed.

FIG. 9 shows an outline of the failure occurrence history registration processing and the screen display processing of the manager 14 described above. The manager 14 includes the probe information collection unit 7
Receiving notification information shown in FIG. 7 from the probe 13 ₁ to 13 _N at 0, it is determined whether either a failure notification, or a failure recovery notice based on the type 62 of the fault (step S80 , Step S83). When it is determined from the collected notification information that the notification is a failure occurrence notification (step S80: Y), the notification information is registered in the database unit 71 (step S81). Then, the occurrence of the failure is notified on the screen display unit 72 together with the occurrence location and the notification time (step S82). On the other hand, when the notification information is received in step S80 and it is determined that the notification is a recovery notification based on the type of the failure (step S80: N, step S83: Y), the database unit 71 is notified of the failure recovery. The information is registered (step S84).
Then, a notification of failure recovery is made on the screen display unit 72 together with the failure recovery time (step S85). Further, in step S83, when neither the failure occurrence notification nor the recovery notification is made (step S83: N), each probe 13
Wait for the notification information notified from _{1 to} 13 _N to be received.

In this way, the manager 14 records the failure occurrence and its recovery history in the database 71, and stores the following failure occurrence history.

FIG. 10 shows such a database unit 71.
1 shows an outline of the configuration of the failure occurrence history recorded in the log. That is, the failure history 90 includes a probe identifier 91 for identifying a probe that has been notified of the occurrence of a failure, link information 92 for identifying the location of the occurrence, a type 93 of the failure that has occurred, a failure occurrence notification time 94, The recovery notification time 95 is recorded in association with the time. By referring to such a failure occurrence history 90 by a network administrator, it becomes possible to quickly take measures for early recovery of a failure location, identification of a congestion occurrence location, and its avoidance.

[0047] So far the network state monitoring apparatus according to the present embodiment as described, for transmitting the occurrence and recovery notification of detected faults by each frame switch 11 ₁ to 11 _M of the frame relay network 10 in the network CLL generated in
The M messages, and so as to monitor the probe 13 ₁ to 13 _N of the first to N throughout the reticuloendothelial 10. Then, a fault or congestion occurring in the network from CLLM messages detected by the probe 13 ₁ to 13 _N, their occurrence point, by further collecting and disaster recovery state manager 14, fault tolerance for network administrators Has been improved so that the maintainability of the network can be improved.

Although the present embodiment has been described on the assumption that the frame relay network and the CLLM message generated in the network are used, the present invention is similarly applied, for example, if a packet switching network and a message that is replaced with the CLLM message are generated. Therefore, the present invention is not limited to the frame relay network as in the present embodiment.

[0049] In the present embodiment it has been so equipped with a probe 13 ₁ to 13 _N of the first to N to monitor CLLM messages everywhere to the network 10 is limited to the number of installed probe Not something. For example, only one probe may be installed, which is appropriately determined according to the scale and cost of the network 10.

Further, in this embodiment, each of the probes 13 ₁ to 13 ₁
The notification information notified from 13 _N to the manager 14 and the failure history recorded in the database unit 71 of the manager 14 are not limited to the information shown in FIGS. 7 and 10, respectively. For example, the notification information can monitor only specific communication data. Further, the fault recovered from the fault occurrence history can be deleted after a predetermined time has elapsed.

[0051]

As described above, according to the first aspect of the present invention, a network message transmitted in a network and including the communication state of the data link in the network is transmitted to an arbitrary data link. From the message detection means to extract the communication state of each data link,
The communication state in the network can be managed at low cost as compared with monitoring the communication state by connecting an exchange in the network. Further, the exchange itself can be downsized.

According to the second aspect of the present invention, it is possible to collect the state of occurrence of a fault or congestion that has occurred in the network, so that the network administrator can quickly recognize the fault that has occurred and manage the network to be managed. It is possible to take immediate measures to maximize throughput.
Therefore, the utilization efficiency of network resources can be improved.

According to the third aspect of the present invention, since network management based on statistical data can be performed, resource allocation is flexibly performed for a data link whose traffic should be increased or decreased. , The maximum throughput can be obtained with a small number of resources.

Further, according to the invention of claim 4, it is possible to promptly take the best countermeasure by promptly notifying the network administrator, and the network in which the recovery from the failure is quick is comfortable for the user. Realize communication.

Further, according to the fifth aspect of the present invention,
It can be applied in the traditional Internet world.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an outline of a configuration of a network condition monitoring apparatus according to an embodiment of the present invention.

FIG. 2 is a format configuration diagram showing an outline of a frame format configuration in the present embodiment.

FIG. 3 is a format configuration diagram showing an outline of a configuration of a CLLM message in the embodiment.

4 is a block diagram showing a main part of SW11 ₁ configuration in the present embodiment.

FIG. 5 is a block diagram illustrating a main part of a configuration of a _first probe 131 according to the present embodiment.

FIG. 6 is a flowchart showing an outline of processing of a _first probe 131 in the present embodiment.

7 is a format diagram showing an outline of a configuration of the notification information to the first probe 13 ₁ from the manager 14 in this embodiment.

FIG. 8 is a block diagram illustrating a main part of a configuration of a manager 14 according to the present embodiment.

FIG. 9 is a flowchart showing an outline of processing of a manager 14 in the embodiment.

FIG. 10 is a configuration diagram illustrating an outline of a failure occurrence history according to the present embodiment.

[Explanation of symbols]

Reference Signs List 10 frame relay network 11 _{1 to} 11 _M SW 12 _{1 to} 12 _N frame line 13 _{1 to} 13 _N first to Nth probes 14 manager

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Hiroshi Tahara, Inventor 5-7-1 Shiba, Minato-ku, Tokyo Within NEC Corporation (72) Inventor Naohiro 1-chome, Kosugicho, Nakahara-ku, Kawasaki City, Kanagawa Prefecture No. 403 NEC Telecom System Co., Ltd. (72) Inventor Mahiro Shimozen 1-403 Kosugi-cho, Nakahara-ku, Kawasaki-shi, Kanagawa F-term within NEC Telecom System Co., Ltd. 5K019 AA02 AB06 AC09 BB21 DA01 DA03 DB08 DC01 DC02 5K030 GA11 HA09 HB00 JA10 MA01 MB01 MC07

Claims (5)

[Claims] 1. A message detecting means for detecting a message in a network including a communication state of a data link in a network from communication data flowing through an arbitrary data link in the network, and a message included in the message detected by the message detecting means. A message extracting means for extracting a communication state of the data link, and a message collecting means for collecting a communication state of the data link extracted by the message extracting means. 2. An in-network message including a state of occurrence of a failure due to a failure or congestion of a data link in a network and link information for specifying a data link in which the occurrence is detected from communication data flowing through an arbitrary data link in the network. A message detecting means for detecting, a message extracting means for extracting a fault occurrence state due to a data link failure or congestion contained in the message detected by the message detecting means and the link information, and a message extracting means for extracting the link information. And a message collecting means for collecting the data link failure occurrence status and the link information as failure occurrence information. 3. An in-network message including a state of occurrence of a failure due to a failure or congestion of a data link in a network and link information for specifying a data link which has detected the occurrence of the failure from communication data flowing through an arbitrary data link in the network. A message detecting means for detecting, a message extracting means for extracting a fault occurrence state due to a data link failure or congestion contained in the message detected by the message detecting means and the link information, and a message extracting means for extracting the link information. Fault occurrence information holding means for holding the fault occurrence state and the link information, and the occurrence of the fault is not detected after a predetermined time has passed since the occurrence of the fault held in the fault occurrence information holding means is notified. Sometimes, a recovery notifying means for notifying the recovery of this failure, A message collection unit that collects, as failure occurrence information, a failure occurrence state of the data link extracted by the message extraction unit, the link information, and a failure recovery notification notified by the recovery notification unit. Network condition monitoring device. 4. The system according to claim 2, further comprising an external notifying unit for notifying the occurrence of a failure or its recovery to the outside based on the failure occurrence information collected by said message collecting unit. Network condition monitoring device. 5. The network condition monitoring device according to claim 1, wherein said network is a frame relay network, and said message is an integrated link layer management message.