Network management device, method, and program

Abstract

A network management device according to one embodiment has: a specification unit that, when a communication failure alarm from any of a plurality of communication devices in a network configuration is activated, specifies a communication path passing through the plurality of communication devices to which the alarm pertains and another communication device between said plurality of communication devices; a calculation unit that calculates, for the other communication device through which the communication path specified by the specification unit passes, the ratio of the number of communication paths specified by the specification unit that pass through said communication device to the number of all of the communication paths that pass through said communication device; and a determination unit that, on the basis of the ratio calculated by the calculation unit, determines a communication device that is a suspected location for the occurrence of the communication failure, among any communication devices that are communication devices through which the communication path specified by the specification unit passes and are other than the communication devices to which the alarm pertains.

Description

Network management device, method and program

[0001] FIELD Embodiments of the present invention relate to a network management device, method, and program.

[0002] In a network configuration (see, for example, Patent Documents 1 to 3) realized with multiple communication network (NW) devices (sometimes referred to as communication devices or simply devices), when a failure occurs in communication by this device or surrounding communication devices due to a malfunction of one of the communication devices, the device or the building in which the device is housed is identified as the location of the failure based on the content of the alarm issued in response to the occurrence of the failure, and the impact of the failure is then assessed.

[0003] Japanese Patent No. 6655524 Japanese Patent No. 7107158 Japanese Patent No. 6837022

[0004] On the other hand, the above-mentioned alarm may not be issued, for example, because all functions of the communication device where the failure occurred have stopped. In such an event where an alarm is not issued, the failure cannot be detected by the monitoring system, which can delay the initial response to the failure. Furthermore, alarms issued from communication devices surrounding the communication device where the failure occurred (sometimes called related alarms) can become noise, raising concerns that the exact failure situation cannot be grasped. In large-scale networks, the volume of related alarms is so large that it becomes difficult to grasp the impact of failures caused by devices that do not issue alarms and to identify the location of the failure, which can potentially increase the workload of operational tasks to identify the cause of the failure.

[0005] The present invention has been made in light of the above circumstances, and its purpose is to provide a network management device, method, and program that can appropriately determine which communication device has experienced a failure.

[0006] A network management device according to one embodiment of the present invention comprises: an identification unit that, when an alarm is issued for a communication failure by one of a plurality of communication devices in a network configuration, identifies communication paths that pass through the plurality of communication devices related to the alarm and other communication devices between the plurality of communication devices; a calculation unit that calculates, for the other communication devices through which the communication paths identified by the identification unit pass, the ratio of the number of communication paths that pass through the communication device to the number of all communication paths that pass through the communication device; and a determination unit that determines, based on the ratio calculated by the calculation unit, a communication device that is suspected of causing the communication failure among the communication devices through which the communication paths identified by the identification unit pass, other than the communication device related to the alarm.

[0007] A network management method according to one embodiment of the present invention is a method performed by a network management device, and includes the following steps: when an alarm is issued for a communication failure by one of a plurality of communication devices in a network configuration, an identification unit of the network management device identifies communication paths that pass through the plurality of communication devices related to the alarm and other communication devices between the plurality of communication devices; a calculation unit of the network management device calculates, for the other communication devices through which the communication paths identified by the identification unit pass, a ratio of the number of communication paths that pass through the communication device identified by the identification unit to the number of all communication paths that pass through the communication device; and a determination unit of the network management device determines, based on the ratio calculated by the calculation unit, a communication device that is suspected of causing the communication failure among the communication devices through which the communication paths identified by the identification unit pass, other than the communication device related to the alarm.

[0008] According to the present invention, it is possible to appropriately determine which communication device has experienced a failure.

[0009] FIG. 1 is a diagram showing an example of an application of a network management device according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of each unit of a failure impact determination processing unit. FIG. 3 is a flowchart showing an example of the procedure of processing operations by a suspected failure location determination processing unit. FIG. 4 is a diagram showing a specific example of determining a suspected failure location. FIG. 5 is a diagram showing an example of a display accompanying the determination result of a suspected failure location. FIG. 6 is a block diagram showing an example of the hardware configuration of a network management device according to an embodiment of the present invention.

[0010] An embodiment of the present invention will now be described. Fig. 1 is a diagram showing an application example of a network management device according to an embodiment of the present invention. As shown in Fig. 1, a network management device 100 according to an embodiment of the present invention includes a failure effect determination processor 10, a Spec (Specification) DB 20, an Entity DB 30, an external information input unit 40, a control unit 50, and an information output unit 60.

[0011] The Spec DB 20 stores network equipment information (Spec (Specification)). The Entity DB 30 stores topology information, which is network equipment information (Entity). This equipment information defines (1) the relationships between objects in the physical layer, (2) the relationships between objects in the logical layer, and (3) the relationships between objects in the physical layer and objects in the logical layer.

[0012] The physical layer can be configured using entities (information objects) consisting of PS (Physical Structure), PD (Physical Device), PP (Physical Port), AS (Aggregate Section), PL (Physical Link), and PC (Physical Connector). The logical layer can be configured using entities consisting of TL (Topological Link), NFD (Network Forwarding Domain), TPE (Termination Point Encapsulation), NC (Network Connection), LC (Link Connect), and XC (Cross (X) Connect). This allows the physical layer and logical layer configurations to be maintained in a unified format.

[0013] Entity names in the physical layer can be categorized into the above PS, PD, PP, AS, PL, and PC. The "Entity name: meaning: correspondence" for each entity name is as follows: ・PS: Facilities such as housing buildings and manholes: equipment object ・PD: Equipment: equipment object ・PP: Communication port of equipment: port object ・AS: Cable: medium object ・PL: Cable core: medium object ・PC: Cable connector: medium object Entity names in the logical layer can be categorized into the above TL, NFD, TPE, NC, LC, and XC. The "Entity name: meaning: correspondence" for each entity name is as follows:・TL: Connectivity between devices (within the Logical Device Layer (sometimes called the LD layer)): line object ・NFD: Transferable range within a device (within the Logical Device Layer): line or plane object ・TPE: Communication termination point: point object ・NC: End-end connectivity formed by LC (Link Connect) and XC (Cross (X) Connect) (within the communication layer): communication object ・LC: Connectivity between devices (within the communication layer): line or plane object ・XC: Connectivity within a device (within the communication layer): line or plane object This section explains the Spec (physical layer) of facility information. In the physical layer, attributes that are unique information such as device name or cable type are stored in the Spec DB 20 as information in which Spec classes (which define attributes that indicate characteristics) are instantiated. Specifically, the following Spec classes are defined:

[0014] The "Spec name: meaning" of the Spec classes in the physical layer is as follows: PS Spec (Physical Structure Specification): defines attributes unique to each PS PD Spec (Physical Device Specification): defines attributes unique to each PD PP Spec (Physical Port Specification): defines attributes unique to each PP AS Spec (Aggregate Section Specification): defines attributes unique to each AS PL Spec (Physical Link Specification): defines attributes unique to each PL PC Spec (Physical Connector Specification): defines attributes unique to each PC Next, the Spec (logical layer) of facility information will be explained. In the logical layer, attributes unique to each layer (VLAN ID, IP address, wavelength number, etc.) are stored in the Spec DB 20 as information in which the respective Spec classes are instantiated. Specifically, the following Spec classes are defined:

[0015] The "Spec name: meaning" of the Spec classes in the logical layer is as follows: ・TL Spec (Topological Link Specification): Defines attributes specific to each TL ・NFD Spec (Network Forwarding Domain Specification): Defines attributes specific to each NFD ・TPE Spec (Termination Point Encapsulation Specification): Defines attributes specific to each TPE ・NC Spec (Network Connection Specification): Defines attributes specific to each NC ・LC Spec (Link Connect Specification): Defines attributes specific to each LC ・XC Spec (Cross(X) Connect Specification): Defines attributes specific to each XC Furthermore, the attributes common to the layers and their values ​​are stored in the Entity DB 30 when the Entity class is instantiated.

[0016] The equipment information stored in the Spec DB 20 defines an attribute that indicates the tier information (skuNumber) of multiple devices (PD) on the same communication path (sometimes simply referred to as a path). This device tier information can be assigned and modified as desired by the user.

[0017] In the hierarchical information, a device with a smaller numerical value is defined as a device at a higher level (hereinafter referred to as a higher-level device), and a device with a larger numerical value is defined as a device at a lower level (hereinafter referred to as a lower-level device). That is, the network equipment information in this embodiment includes hierarchical information of multiple communication devices that can communicate via a communication path.

[0018] 2 is a diagram illustrating an example of each unit of the failure impact determination processor. As shown in FIG. 2, the failure impact determination processor 10 has a suspected failure location determination processor 11, an affected path calculation processor 12, and an apparatus failure determination processor 13. The suspected failure location determination processor 11 has a communication path identification unit 11a, a calculation unit 11b, a determination unit 11c, and a display processor 11d. The apparatus failure determination processor 13 has an affected path acquisition processor 13a, an apparatus information acquisition processor 13b, an apparatus stage determination processor 13c, a failure spread determination processor 13d, and a backup power supply depletion determination processor (a backup power supply depletion time determination processor) 13e.

[0019] 3 is a flowchart showing an example of the procedure of the processing operation by the suspected fault location determination processing unit 11. First, as a pre-setting, a path number ratio N (to be described later), which is a criterion for determining a suspected fault location, is stored in the internal memory of the suspected fault location determination processing unit 11 (S11).

[0020] The external information input unit 40 inputs and acquires alarm information that is issued when the communication function of another communication device is stopped due to the influence of a failure or the like of a communication device (S12).

[0021] The communication path identification unit 11a of the suspected failure location determination processing unit 11 identifies all communication paths that pass through the multiple communication devices that issued the alarms indicated in the alarm information acquired in S12 and other communication devices between the multiple communication devices, and acquires information indicating these communication paths (S13). The communication paths indicated by this information may be communication paths that start from the first communication device that issued the alarm and end at the second communication device, passing through other communication devices that may or may not have issued an alarm.

[0022] The communication path identification unit 11a selects one unselected communication path from all communication paths indicated by the information acquired in S13, and acquires information on communication devices linked to this selected communication path, i.e., communication devices through which the communication path passes, from topology information (S14). The communication devices indicated by this information are communication devices through which the selected communication path passes, including the first and second communication devices that issued the alarm, and communication devices between these communication devices. The processing of S14 is repeated until processing has been completed for all communication paths indicated by the information acquired in S13, i.e., all communication paths that pass through the communication device that issued the alarm indicated by the alarm information acquired in S12.

[0023] When the processing of S14 is completed, the calculation unit 11b selects one unselected communication device from among the communication devices indicated by the information acquired in S14, i.e., the communication devices through which the communication paths acquired in S13 pass, and calculates the ratio between the number of all communication paths passing through this selected communication device and the number of communication paths indicated by the information acquired in S13 among all the communication paths (S15).

[0024] Next, when the path count ratio calculated in S15 satisfies the ratio N set in S11 (Yes in S16) and no alarm has been issued from the communication device selected in S15 for calculating the path count ratio (No in S17), the determination unit 11c determines that the selected communication device is a suspected fault location for which no alarm has been issued (S18). Also, when the determination in S16 is "Yes" and an alarm has been issued from the communication device selected in S15 for calculating the path count ratio (Yes in S17), the determination unit 11c excludes the selected communication device from the list of devices to be determined as suspected fault locations. The processes in S15 to S18 are repeated until all communication devices indicated by the information acquired in S14 have been processed.

[0025] After S18 is completed, the display processing unit 11d causes the information output unit 60 to display information about the communication device that was determined to be a suspected fault location in S18 in a color that has been changed so as to distinguish it from the color of a communication device that has not been determined to be a suspected fault location (S19).

[0026] 4 shows a specific example of how to determine a suspected fault location. Here, we will explain an example of how to determine a suspected fault location when device A fails and, as a result of this failure, related alarms a1 to a4 are generated from devices B, C, D, and E surrounding device A, as shown in FIG.

[0027] 4, four paths pass through device A, and three communication paths pass through devices B, C, D, E, F, and G. One path passing through device B passes through device F and device D in that order, and the remaining two paths passing through device B pass through device A and device D in that order. Two paths passing through device C pass through device A and device E in that order, and the remaining path passing through device C passes through device G and device E in that order.

[0028] In the example shown in Figure 4, as a result of the failure of device A as described above, device B experiences a failure b1 in the communication function between device A, device C experiences a failure b2 in the communication function between device A, device D experiences a failure b3 in the communication function between device A, and device E experiences a failure b4 in the communication function between device A, resulting in alarm a1 from device B, alarm a2 from device C, alarm a3 from device D, and alarm a4 from device E being issued.

[0029] In this state where a failure has occurred and an alarm has been issued, as a preliminary step, the external information input unit 40 is operated to arbitrarily set "100%" as the ratio N, which is the criterion for determining the suspected failure location and is the determination criterion for the number of paths, which will be described later. The control unit 50 transmits this set ratio N to the failure impact determination processing unit 10. Next, the following processes (1) to (4) are performed.

[0030] (1) The communication path identification unit 11a of the suspected fault location determination processing unit 11 acquires, within a local range, information on all paths that pass through the device that is issuing the alarm. Here, the communication path identification unit 11a acquires information on at least two of the four devices B, C, D, and E that are issuing the alarm as described above, and paths that pass through other devices between these devices, that is, information on a total of six paths shown in (1-1) to (1-4) below: (1-1) One path that passes through devices B, F, and D in this order; (1-2) Two paths that pass through devices B, A, and D in this order; (1-3) Two paths that pass through devices C, A, and E in this order; (1-4) One path that passes through devices C, G, and E in this order.

[0031] (2) The communication path identification unit 11a of the suspected failure location determination processing unit 11 refers to the topology information stored in the Entity DB 30, and the calculation unit 11b uses the total number of paths passing through each device through which at least one of the paths obtained in (1) above passes as a parameter, and calculates the ratio of the number of paths obtained in (1) above to this total number.

[0032] Here, the calculation results shown in (2-1) to (2-3) below are obtained for each of devices A to G through which at least one of the paths acquired in (1) above passes. Note that devices B, C, D, and E below do not need to be included in the calculation.

[0033] (2-1) (Device for which ratio is calculated: Device A) Total number of paths passing through the device for which calculation is made: 4, Number of paths acquired in (1) above: 4, Calculated ratio result: 4 / 4 (= 100%) (2-2) (Device for which ratio is calculated: Each of Devices B, C, D, and E) Total number of paths passing through the device for which calculation is made, for example, Device B: 3, Number of paths acquired in (1) above: 3, Calculated ratio result: 3 / 3 (= 100%) (2-3) (Device for which ratio is calculated: Each of Devices F and G) Total number of paths passing through the device for which calculation is made, for example, Device F: 3, Number of paths acquired in (1) above: 1, Calculated ratio result: 1 / 3 (less than 100%) That is, the calculated result of the above ratio for each of devices A, B, C, D, and E through which the path obtained in (1) above passes is 100%, and the calculated result of the above ratio for each of devices F and G through which the path obtained in (1) above passes is less than 100%.

[0034] (3) The determination unit 11c of the suspected fault location determination processing unit 11 determines, as a device having a suspected fault location, the device whose ratio calculated in (2) above satisfies "100%", which is the ratio N set as the determination criterion. However, among the devices for which the ratio is calculated, devices that are issuing the above alarm are excluded from the devices to be determined as having a suspected fault location.

[0035] In the example shown in Figure 4, of the devices A to G for which the above percentages have been calculated, the devices for which the percentages satisfy the above-mentioned judgment criterion of percentage N (100%) are devices A to E. However, since devices B to E are devices that have issued alarms, they are excluded from the devices to be judged as devices with suspected fault locations. As a result, device A is judged as a device with a suspected fault location for which no alarm has been issued.

[0036] 5 is a diagram showing an example of a display accompanying the suspected failure location determination result. (4) Next, the display processing unit 11d of the suspected failure location determination processing unit 11 draws various communication devices and communication paths passing through the communication devices according to the topology information, and causes the information output unit 60 to display the same. Here, the display processing unit 11d draws the display form, for example, color decoration, of the device determined to be a suspected failure location for which no alarm has been issued in the above (3) in a display form different from the display form of other devices, for example, devices for which an alarm has been issued, and causes the information output unit 60 to display the same. In the example shown in FIG. 5, the color of the display form of device A determined to be a suspected failure location for which no alarm has been issued in the above (3) is displayed in a color different from the colors of other communication devices, including the device for which an alarm has been issued, as shown by symbol c in FIG. 5.

[0037] Next, the processing by the impact path calculation processing unit 12 and the device failure determination processing unit 13 of the failure impact determination processing unit 10 will be described. Details of the relevant processing are also described in International Publication No. 2023 / 233635. Upon receiving the determination result by the suspected failure location determination processing unit 11, the impact path calculation processing unit 12 of the failure impact determination processing unit 10 calculates, based on the equipment information stored in the Entity DB 30, an object in the logical layer corresponding to the failure location in the physical layer (here, the object related to the suspected failure location) as a basic path affected by the failure. Here, when a failure (failure) occurs in one device in the physical layer, multiple NCs corresponding to this device on the logical layer are calculated as basic paths affected by the failure. Hereinafter, the device and the NC corresponding to this device on the logical layer will be described as having a connection relationship.

[0038] Next, the affected path acquisition processing unit 13a of the device failure determination processing unit 13 acquires, in an array, a list of the basic paths affected by the failure calculated above from the network facility information.

[0039] Next, if there are any unprocessed elements among the NCs that are elements of this acquired array for subsequent processing, the device information acquisition processing unit 13b acquires one of the unprocessed elements, that is, a device connected to one end of the basic path, from the network equipment information as information on the starting device, and acquires information on the device connected to the other end of the basic path from the network equipment information as information on the ending device.

[0040] Next, the device stage determination processing unit 13c acquires the stage information of the starting device and the stage information of the ending device indicated by the information acquired by the device information acquisition processing unit 13b from the facility information of the network.

[0041] If the value of the stage information of the starting device is equal to or greater than the value of the stage information of the ending device, the device stage determination processing unit 13c determines that the starting device indicated by the information acquired by the device information acquisition processing unit 13b is a device that will be affected by the occurrence of a failure.

[0042] When the value of the staircase information of the starting device is not greater than or equal to the value of the staircase information of the terminating device, or after determining the device that will be affected by the occurrence of the failure, if the value of the staircase information of the terminating device is greater than or equal to the value of the staircase information of the starting device, the device staircase determination processing unit 13c determines that the terminating device indicated by the information acquired by the device information acquisition processing unit 13b is a device that will be affected by the occurrence of the failure.

[0043] The fault spread determination processing unit 13d obtains information on the device in which the fault occurred and the device determined to be affected by the fault from the network equipment information as a first acquisition result. If there are any unprocessed elements in the subsequent processing among the devices that are elements of the array indicated by this obtained information, the fault spread determination processing unit 13d obtains information on the NCs connected to the devices for each device corresponding to this element in an array from the network equipment information as a second acquisition result.

[0044] If there are any unprocessed elements among the NCs that are elements of the array indicated by this acquired information, the fault spread determination processing unit 13d acquires information on the opposing device connected to each NC, except for the NCs that have been processed once. This opposing device is a device that is connected to one end of the NC indicated by the second acquired result when one end of this NC is connected to the device indicated by the first acquired result.

[0045] The fault spread determination processing unit 13d obtains the stage information of both devices, that is, the device indicated in the first acquisition result, and the stage information of the opposite device for this device, and if there is an "NC to which these devices are connected when the affected device is higher (including the same level) than the opposite device," it selects this NC from the NCs indicated in the second acquisition result and stores information indicating this NC in its internal memory. If there is such a stored NC, the fault spread determination processing unit 13d determines that the stored NC is the NC to which the effects of the fault have spread.

[0046] The failure influence determination processing unit 13d then newly determines that the opposite device connected to this NC is a device that will be affected by the failure.

[0047] Next, the standby power supply depletion determination processing unit 13e receives input of faulty building information that identifies at least one building (here, each of a plurality of buildings) that houses the failed main power supply. This faulty building information corresponds to the building that houses the failed main power supply among the PSs that house each object indicated by the facility information stored in the Entity DB 30. This faulty building information may be received by input operation by an operator, or may be information generated when a failure in the main power supply is detected by a detection device (not shown).

[0048] The backup power supply depletion determination processing unit 13e receives input of the backup power supply depletion time, which is the time during which the backup power supply housed in the building indicated in the received failed building information can operate, i.e., the time until the power that can be supplied by the backup power supply is depleted when the main power supply is not restored. This backup power supply depletion time may be associated in advance with the facility information stored in the Entity DB 30 and stored in the Entity DB 30.

[0049] The backup power supply depletion determination processing unit 13e accepts input of the start time and end time of an impact simulation, which is a simulation of the impact on the operation of the equipment, i.e., the communication device, due to the operation and depletion of the backup power supply when a failure of the main power supply is assumed to occur.

[0050] Next, the standby power supply depletion determination processing unit 13e determines whether or not there is a building among the buildings indicated in the above-mentioned failed building information whose standby power supply will be depleted between the above-mentioned start time and end time.

[0051] In this embodiment, status information indicating whether or not there is a power outage fault in each building is associated in advance with, for example, facility information stored in the Entity DB 30, and is stored in this Entity DB 30. In the initial state, the status is set to "normal."

[0052] When it is determined that there is a building whose backup power supply is depleted, the backup power supply depletion determination processing unit 13e changes and sets the status of the relevant building, i.e., the building whose backup power supply is depleted, to "power off."

[0053] In the embodiment described above, it is possible to narrow down the devices where a failure has occurred by determining suspected failure locations where no alarm has been issued, without checking the entire data of the network configuration information or the details of the communication paths. Also, by narrowing down the devices where a failure has occurred that will not issue an alarm, it is possible to reduce the work of determining the location of a failure based on alarms issued from multiple devices.

[0054] 6 is a block diagram showing an example of the hardware configuration of a network management device according to an embodiment of the present invention. In the example shown in FIG. 6, the network management device 100 according to the embodiment is configured, for example, as a server computer or a personal computer, and has a hardware processor 111A such as a CPU (Central Processing Unit). A program memory 111B, a data memory 112, an input / output interface 113, and a communication interface 114 are connected to this hardware processor 111A via a bus 115.

[0055] The communication interface 114 includes, for example, one or more wireless communication interface units, and enables transmission and reception of information to and from a communication network. As the wireless interface, for example, an interface that adopts a low-power wireless data communication standard such as a wireless LAN (Local Area Network) is used.

[0056] An input device 200 and an output device 300 attached to the network management device 100 and used by a user or the like are connected to the input / output interface 113. The input / output interface 113 can take in operation data input by a user or the like through the input device 200, such as a keyboard, touch panel, or touchpad, and can output and display output data to an output device 300, which may include a display device using a liquid crystal or organic electroluminescence (EL) display. The input device 200 and the output device 300 may be devices built into the network management device 100, or may be input devices and output devices of other information terminals that can communicate with the network management device 100 via a network.

[0057] The program memory 111B is a non-transitory tangible storage medium that is a combination of a non-volatile memory that can be written to and read from at any time, such as a hard disk drive (HDD) or a solid state drive (SSD), and a non-volatile memory such as a read only memory (ROM), and can store programs necessary to execute various control processes, etc., according to one embodiment.

[0058] The data memory 112 is a tangible storage medium that is, for example, a combination of the above-mentioned nonvolatile memory and a volatile memory such as RAM (Random Access Memory), and can be used to store various data or information acquired and created during various processes.

[0059] The network management device 100 according to one embodiment of the present invention can be configured as a data processing device having the units shown in FIG. 1 as software-based processing functional units.

[0060] The information storage unit used as a work memory or the like by each unit of the network management device 100 can be configured using the data memory 112 shown in Fig. 6. However, these configured storage areas are not essential components within the network management device 100, and may be areas provided in, for example, an external storage medium such as a USB (Universal Serial Bus) memory, or a storage device such as a database server located in the cloud.

[0061] The processing function units in each of the above units can be realized by reading and executing a program stored in the program memory 111B by the hardware processor 111A. Note that some or all of these processing function units may be realized in various other forms, including integrated circuits such as an application specific integrated circuit (ASIC) or a field-programmable gate array (FPGA).

[0062] The methods described in each embodiment can be stored as a program (software means) that can be executed by a computer on a recording medium such as a magnetic disk (floppy disk, hard disk, etc.), optical disk (CD-ROM, DVD, MO, etc.), or semiconductor memory (ROM, RAM, flash memory, etc.), and can also be distributed by transmitting it via a communication medium. The program stored on the medium also includes a configuration program that configures the software means (including not only execution programs but also tables or data structures) that the computer executes. The computer that realizes this device reads the program stored on the recording medium and, in some cases, configures the software means using the configuration program, and executes the above-mentioned processing by controlling the operation of this software means. The term "recording medium" as used herein is not limited to a storage medium for distribution, but also includes a storage medium such as a magnetic disk or semiconductor memory installed inside the computer or in a device connected via a network.

[0063] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0064] REFERENCE SIGNS LIST 100... network management device 10... failure influence determination processing unit 11... suspected failure location determination processing unit 11a... communication path identification unit 11b... calculation unit 11c... determination unit 11d... display processing unit 12... affected path calculation processing unit 13... device failure determination processing unit

Claims

1. A network management device comprising: an identification unit that, when an alarm of a communication failure is issued by one of a plurality of communication devices in a network configuration, identifies communication paths that pass through the plurality of communication devices related to the alarm and other communication devices between the plurality of communication devices; a calculation unit that calculates, for the other communication devices through which the communication paths identified by the identification unit pass, the ratio of the number of communication paths that pass through the communication device to the number of all communication paths that pass through the communication device; and a determination unit that determines, based on the ratio calculated by the calculation unit, a communication device that is suspected of the occurrence of the communication failure among the communication devices through which the communication paths identified by the identification unit pass, other than the communication device related to the alarm.

2. A network management device as described in claim 1, which displays information indicating the communication device related to the alarm, and also displays information indicating the communication device determined by the determination unit to be the suspect location separately from information indicating the communication device related to the alarm.

3. A network management method performed by a network management device, comprising: when an alarm of a communication failure is issued by one of a plurality of communication devices in a network configuration, an identification unit of the network management device identifies communication paths that pass through the plurality of communication devices related to the alarm and other communication devices between the plurality of communication devices; a calculation unit of the network management device calculates, for the other communication devices through which the communication paths identified by the identification unit pass, a ratio of the number of communication paths that pass through the communication device identified by the identification unit to the number of all communication paths that pass through the communication device; and a determination unit of the network management device determines, based on the ratio calculated by the calculation unit, a communication device that is suspected of the occurrence of the communication failure among the communication devices through which the communication paths identified by the identification unit pass, other than the communication device related to the alarm.

4. A network management processing program that causes a processor to function as each unit of the network management device according to claim 1 or 2.

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