Network management device and method

Abstract

A network management device according to one embodiment comprises: an extraction unit that, when a failure has occurred in a predetermined section of a route in a network configuration, extracts a failure influence range in the network configuration due to the occurrence of the failure in the route, and extracts candidates for a detour of a route related to provision of a service using the network configuration in a range limited to the extracted failure influence range; and an output unit that, on the basis of a rule in which an appropriate route is determined as the detour when the predetermined section is included in the route in which the failure has occurred, specifies and outputs an appropriate route as the detour among the candidates extracted by the extraction unit.

Description

Network management apparatus and method

[0001] FIELD OF THE INVENTION An embodiment of the present invention relates to a network management apparatus and method.

[0002] When a failure occurs in a large-scale system related to a communication network (sometimes simply referred to as a network (NW)), it is necessary to quickly identify the location of the failure and quickly understand the impact on services (sometimes simply referred to as the impact) (see, for example, Patent Documents 1, 2, and 3).

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

[0004] When a failure occurs in a large-scale system, as described above, it is necessary to grasp the impact and quickly communicate the information to users. This information must not only be about the impact on the network, but also about each service provided on the network, i.e., each of the multiple types of services.

[0005] In order to understand the impact of each service provided on the network, it is necessary to understand the communication path that indicates the order in which each service passes through the nodes on the constructed communication network for each service.

[0006] A service impact assessment technology that uses NOIM (Network Operation Injected Model), a conventional network resource management technology, involves linking a general-purpose network (NW) model with route information to assess the impact on each service. However, in order to assess the impact, it is necessary to quickly create route information and input it into the model.

[0007] The method of completely reproducing design information and simulating communication routes requires that all processing of each protocol be reproduced in order to make calculations, and therefore is not suitable for use cases that require rapid detection of large-scale system failures in large-scale networks owned by telecommunications carriers.

[0008] Furthermore, if the communication protocols are narrowed down and calculations are simplified to shorten calculation time, there is a risk that the impact on services will be incorrectly understood because there will be failure patterns that cannot be reproduced.

[0009] In particular, when a protocol is used that calculates communication routes by assuming virtual nodes and links on a physical network, calculations are required under conditions in which a virtual topology is constructed on top of the real topology, so the amount of calculation required to completely reproduce the design information becomes enormous, and simplifying the calculations as described above results in patterns in which the communication routes cannot be reproduced.

[0010] In conventional impact assessment technologies and communication path calculation technologies, firstly, when autonomous calculation results of communication paths between nodes are updated using virtual nodes and links, there is no logic that can calculate communication paths in a short time in the event of a failure in a large-scale system and that can calculate communication paths with high accuracy in the calculation results.

[0011] Secondly, when a large-scale system fails, it is not possible to calculate a communication path with high accuracy in a short time, and therefore it is not possible to promptly notify users of the accurate impact on services.

[0012] This invention was made in light of the above circumstances, and its purpose is to provide a network management device and method that can appropriately grasp the impact on services caused by the occurrence of a route failure.

[0013] A network management device according to one embodiment of the present invention comprises an extraction unit that, when a failure occurs in a specified section of a route in a network configuration, extracts the extent of the impact of the failure in the network configuration due to the occurrence of the failure in the route, and extracts candidate detour routes for routes related to the provision of services using the network configuration within a range limited to the extracted extent of the impact of the failure; and an output unit that identifies and outputs a suitable detour route from among the candidates extracted by the extraction unit based on rules that define suitable routes as detour routes when the specified section is included in the route in which the failure occurred.

[0014] A network management method according to one aspect of the present invention is a method performed by a network management device, and includes the steps of: extracting, by an extraction unit of the network management device, when a failure occurs in a specified section of a route in a network configuration, the extent of the impact of the failure in the route in the network configuration due to the failure in the route, and extracting candidate detour routes for routes related to the provision of services using the network configuration within a range limited to the extracted extent of the impact of the failure; and; identifying and outputting, by an output unit of the network management device, a suitable route as the detour route from among the candidates extracted by the extraction unit, based on rules that define suitable routes as the detour route when the specified section is included in the route in which the failure occurred.

[0015] According to the present invention, it is possible to appropriately grasp the effect on services caused by the occurrence of a failure in a route.

[0016] FIG. 1 is a diagram showing an example of application of a network configuration according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of routing under normal conditions. FIG. 3 is a diagram showing an example of routing when a preset rule is applied when an abnormality occurs. FIG. 4 is a diagram showing an example of routing when a preset rule is not applied when an abnormality occurs. FIG. 5 is a diagram showing an example of routing when a preset rule is applied when an abnormality occurs. FIG. 6 is a diagram showing an example of application of a network management device according to an embodiment of the present invention. FIG. 7 is a flowchart showing an example of a processing operation procedure of a network management device according to an embodiment of the present invention. FIG. 8 is a flowchart showing an example of a processing operation procedure of a network management device according to an embodiment of the present invention. FIG. 9 is a block diagram showing an example of the hardware configuration of a network management device according to an embodiment of the present invention.

[0017] In one embodiment of the present invention, actual environment information acquired by tracking is used to calculate a communication path as an appropriate detour route in the event of a failure in a specific link, and the calculated path is replaced with a preset rule, which is a rule that is determined in advance.

[0018] In this embodiment, in addition to the network design policy, information obtained from the actual environment, such as the location of the failure, section information, and accident information, is obtained, and when a disconnection of a section between specific nodes is detected, the above-mentioned preset rules are applied to the limited network range to calculate the communication path.

[0019] The real-world information is tracked using information sharing such as node failure or link disconnection, as well as node reachability information collected by on-site patrols or remote communication checks, and is judged from this reachability.

[0020] The preset rules are determined in advance based on rules that determine detour routes that are expected based on past failures and accidents and the response procedures that are prepared.In the event of a failure, these rules are applied only to specific sections, minimizing the scope and amount of calculation for communication route calculations, thereby improving the speed of communication route calculations.

[0021] Generally, a virtual topology is assumed on top of a physical topology and a communication path is calculated, but in this embodiment, the communication path is calculated based on preset rules, which reduces calculation time and improves the accuracy of the calculation results.

[0022] In this embodiment, the above technology simplifies protocols that use virtual nodes and links when calculating communication paths while ensuring the accuracy of the calculation results, making it possible to quickly determine accurate communication paths even in the event of a system failure in a large-scale network.

[0023] In this way, by quickly and accurately identifying communication paths, it becomes possible to accurately grasp the impact on services at the initial stage when a failure occurs in a large-scale system, and to implement appropriate recovery measures.

[0024] Furthermore, in this embodiment, the application is described as a communication network, but the application is not limited to this, and can be a wide range of infrastructure networks such as transportation or waterworks.

[0025] FIG. 1 is a diagram illustrating an example of a network configuration according to an embodiment of the present invention. In the example illustrated in FIG. 1, a first gateway (GW) "GW0 system" and a second gateway (GW1 system) are provided on the provider side. "0 system" and "1 system" refer to a primary system and a secondary system. The "GW0 system" and "GW1 system" hold RIs (Router Instances), and the "GW0 system" and "GW1 system" are provided with virtual ports related to FW (Forwarding). FW means that a virtual device forcibly forwards packets to a specific route. The RI is an instance that contains routing information when FW is performed.

[0026] Also, a first CR (Core Router) "CR0 system" and a second CR "CR1 system" are provided on the user side, and these are connected to each other via a virtual port. The FW and the virtual port are connected via a virtual link (symbol a in Figure 1). The "CR0 system" and "CR1 system" are connected to the SNI (Server-Network Interface) on the provider side. Furthermore, the "CR0 system" is connected to multiple "ER0 systems" which are first ERs (Edge Routers), and the "CR1 system" is connected to multiple "ER1 systems" which are second ERs. Each pair of "ER0 system" and "ER1 system" is connected to each other, and a "UNI (User-Network Interface)" is connected to this pair.

[0027] Then, within an area consisting of each GW and each CR, route information is redistributed using BGP (Border Gateway Protocol), which is a type of EGP. Also, within an area consisting of each CR and each ER, route information is redistributed using OSPF (Open Shortest Path First), which is a type of IGP. The cost of redistributing route information is the same for each of the "ER0 system" and "ER1 system" pairs.

[0028] Route information advertisement from the GW to the CR (symbol b in Figure 1) is, for example, a GW loopback, a GW-CR transfer, a GW-MI (Master Instance) transfer, or a company communication. Loopback means forwarding from a global port to a virtual port within the same device. MI is an instance with a default routing table.

[0029] The route information advertisement from the CR to the GW (symbol c in FIG. 1) is, for example, an intra-network aggregation or a user route. The route information advertisement from the BCR (virtual port) to the BCR (virtual port) (symbol d in FIG. 1) and the route information advertisement from the BCR (global port) to the BCR (global port) (symbol e in FIG. 1) are, for example, company communications. The route import from the CR (global port) to the CR (virtual port) (symbol f in FIG. 1) is, for example, an intra-network aggregation or a user route. Route import refers to the reflection of a route in a routing table. The route import from the CR (virtual port) to the CR (global port) (symbol g in FIG. 1) is, for example, a GW infrastructure route.

[0030] Next, an example of routing when a specific IF (interface) or link state is monitored and any of them goes down will be explained. Here, the explanation will be given using as an example a network in which the "GW0 system", "GW1 system", "CR0 system", "CR1 system", "ER0 system", and "ER1 system" shown in Figure 1 are provided.

[0031] 2 is a diagram showing an example of routing under normal circumstances. As shown in FIG. 2, when the link between the "CR0 system" and the "CR1 system" (reference symbol a in FIG. 2) is normal, routing by BGP is performed. In this case, the communication route from the UNI is a route that passes through the "ER1 system," "CR1 system," and "CR0 system" to the "GW0 system."

[0032] 3 is a diagram showing an example of routing when a preset rule is applied when an abnormality occurs. On the other hand, as shown in FIG. 3, when a crossing break (symbol a in FIG. 3) between the "CR0 system" and the "CR1 system" is detected, the preset rule for routing in this embodiment is applied, and the setting of a static route (symbol b in FIG. 3) addressed to the business company in the "CR1 system" is enabled. The preset rule here is created based on past failure cases.

[0033] Fig. 4 is a diagram showing an example of routing when a preset rule is not applied when an abnormality occurs. The example shown in Fig. 4 is an example when BGP and OSPF are applied to redistribute route information in a network provided with the "GW0 system," "GW1 system," "CR0 system," "CR1 system," "ER0 system," and "ER1 system" shown in Fig. 1, but the preset rule is not applied when an abnormality occurs.

[0034] In this example, when a link down occurs between the "CR0 system" and the "CR1 system," the cost of redistributing route information within the area made up of each CR and each ER is equalized by applying OSPF, resulting in load balancing. The communication path from the UNI passes through the "ER0 system," "ER1 system," and "CR1 system," then passes through any other pair of "ER1 system" and "ER0 system" to reach the "CR1 system," and then moves on to the "GW0 system" (symbol a in Figure 4).

[0035] Fig. 5 is a diagram showing an example of routing when a preset rule is applied when an abnormality occurs. The example shown in Fig. 5 is an example in which a preset rule is applied when an abnormality occurs in a network in which the "GW0 system," "GW1 system," "CR0 system," "CR1 system," "ER0 system," and "ER1 system" shown in Fig. 1 are provided, and the setting of a static route (symbol a in Fig. 5) addressed to a business company in the "CR1 system" is validated.

[0036] In this example, when a link down occurs between the "CR0 system" and the "CR1 system," the communication path from the UNI is changed to include the "CR1 system" and the "GW1 system" in accordance with the application of the preset rules.

[0037] As a result, the communication path from the UNI no longer includes the "CR0 system," and the communication path from this UNI passes through the "ER0 system," "ER1 system," and "CR1 system," reaches the "CR1 system" and "GW1 system," and then moves on to the "GW0 system."

[0038] Fig. 6 is a diagram showing an application example of a network management device according to an embodiment of the present invention. As shown in Fig. 6, the network management device 100 according to this embodiment has a service route prediction function unit 10, a NW resource information DB (database) 20, an impact assessment function unit 30, and a tracking information DB 40. The NW resource information DB 20 and the impact assessment function unit 30 are applied to existing NOIM applications.

[0039] The service route prediction function unit 10 includes a configuration reading function unit 11 , a management DB 12 , a routing table generation function unit 13 , a route information generation function unit 14 , and a log output function unit 15 .

[0040] The management DB 12 is a DB that is applied to, for example, PostgreSQL, and stores a node information table, an interface information table, an EGP route information table, a static route information table, a redistribution route information table, an IGP external route information table, and a utilization route information table.

[0041] The configuration reading function unit 11 reads an input file (reference symbol a in FIG. 6 ) from the management DB 12. This input file includes device configuration information from NOIM, network design information, affected path information, etc., and further includes information on sections that are out of service when an abnormality occurs in the network. This information on sections that are out of service may be information obtained from the tracking information DB 40 (reference symbol b1 in FIG. 6 ) or information obtained by manual input by an operator (reference symbol b2 in FIG. 6 ).

[0042] The configuration reading unit 11 also reads a preset rule file (reference symbol c in FIG. 6) from an external device. The preset rule is a communication path rule based on past accidents and failures in the network and detour routes assumed in the event of a network abnormality.

[0043] The configuration reading function unit 11 stores input information based on the read input file and the preset rule file in the management DB 12 (symbol d in FIG. 6 ). This input information includes node and interface (IF) information, protocol information, etc.

[0044] The routing table generation function unit 13 reads the input information stored in the management DB 12 (symbol e in FIG. 6 ). The routing table generation function unit 13 generates routing information using the read input information and stores this in the management DB 12 (symbol f in FIG. 6 ).

[0045] The route information generation function unit 14 reads the routing information stored in the management DB 12 (symbol g in Figure 6), uses this routing information to generate route information (symbol h in Figure 6), and outputs it to the impact understanding function unit 30.

[0046] The impact assessment function unit 30 uses the route information output from the route information generation function unit 14 to generate an impact assessment result on the service (symbol i in FIG. 6) and outputs this to, for example, an operator.

[0047] In addition, the log output function unit 15 generates log information (symbol j in Figure 6) indicating the access contents to the management DB 12 by the configuration reading function unit 11, the routing table generation function unit 13, and the route information generation function unit 14, and outputs this to, for example, an operator.

[0048] 7 and 8 are flowcharts showing an example of a procedure for the processing operation of the network management device according to an embodiment of the present invention. The configuration reading function unit 11 of the service route prediction function unit 10 inputs an input file containing information on an interrupted section, which is a fault location indicated by information acquired from the tracking information DB 40 or information acquired manually, stored in the NW resource information DB 20, and preset rules, and stores them in the management DB 12 (S11).

[0049] The routing table generation function unit 13 reads the information on the failure location contained in the input file from the management DB 12, and extracts service paths whose service path status is double-disconnected as candidates for detour routes for the route related to the provision of the service (S12).

[0050] The routing table generation function unit 13 extracts data including the service path extracted in S12 from the device configuration information included in the input file stored in the management DB 12 (S13).

[0051] The routing table generation function unit 13 obtains key information from the data extracted in S13, and based on this key information, obtains routing table generation data from the management DB 12 and excludes information corresponding to the failure location from this data (S14). This key information includes service type information, service area information, and an identifier for uniquely identifying a combination of these pieces of information. If the data excluded in S14 does not include information related to the failure location of a specific link (No in S15), the routing table generation function unit 13 processes the data processed in S14 for each key to determine the route calculation target area (S21).

[0052] The routing table generation function unit 13 creates a routing table for when a failure occurs based on the above-mentioned route calculation target area (S22). The route information generation function unit 14 calculates the optimal route for uplink and downlink between src and dst based on the routing table information (S23). The route information generation function unit 14 generates utilization route information using this optimal route and registers it in the management DB 12 (S24).

[0053] After the processing of S24, if there is unprocessed data related to a key among the data processed in S14 (Yes in S25), the process returns to S21. On the other hand, if there is no unprocessed data related to a key among the data processed in S14 (No in S25), the process outputs the usage route information at the time of the failure (S26).

[0054] When the data excluded in S14 includes information related to the failure location of a specific link, i.e., when the information related to the specific link is excluded from the data for generating the routing table (Yes in S15), the routing table generation function unit 13 processes the data processed in S14 for each key to determine the route calculation target area (S31).

[0055] The routing table generation function unit 13 creates a routing table for when a failure occurs based on this route calculation target area (S32).The routing table generation function unit 13 rewrites the communication routes corresponding to the above-mentioned specific links among the communication routes indicated in this created routing table in accordance with the preset rules stored in the management DB 12 (S33).

[0056] Based on this rewritten routing table, the route information generation function unit 14 calculates the optimum route between src and dst, i.e., between the start point of the route and the destination (S34).The route information generation function unit 14 generates utilization route information using this optimum route and registers it in the management DB 12 (S35).

[0057] After the processing of S35, if there is unprocessed data related to a key among the data processed in S14 (Yes in S36), the process returns to S31. On the other hand, if there is no unprocessed data related to a key among the data processed in S14 after the processing of S35 (No in S36), the usage route information at the time of the failure is output (S37).

[0058] 9 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. 9, 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. 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.

[0059] 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.

[0060] 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 receives operation data input by a user or the like through the input device 200, such as a keyboard, touch panel, touchpad, or mouse, and outputs output data to an output device 300, which may include a display device using a liquid crystal or organic electroluminescence (EL) display, for 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 (NW).

[0061] 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 stores programs necessary to execute various control processes, etc., according to one embodiment.

[0062] The data memory 112 is a tangible storage medium that combines, for example, the above-mentioned nonvolatile memory with a volatile memory such as RAM (Random Access Memory), and is used to store various data acquired and created during various processes performed by the network management device 100.

[0063] The network management device 100 according to an embodiment of the present invention can be configured as an information processing device having a software-based processing function unit.

[0064] The storage areas used as 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. 9. 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.

[0065] The processing function unit can be realized by having the hardware processor 111A read and execute a program stored in the program memory 111B, but the processing function unit may also be realized in various other forms, including an integrated circuit such as an application specific integrated circuit (ASIC) or a field-programmable gate array (FPGA).

[0066] 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.

[0067] 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.

[0068] REFERENCE SIGNS LIST 100... Network management device 10... Service route prediction function unit 11... Configuration reading function unit 12... Management DB 13... Routing table generation function unit 14... Route information generation function unit 15... Log output function unit 20... NW resource information DB 30... Impact understanding function unit 40... Tracking information DB

Claims

1. A network management device comprising: an extraction unit that, when a failure occurs in a specified section of a route in a network configuration, extracts the extent of the impact of the failure in the network configuration due to the occurrence of the failure in the route, and extracts candidate detour routes for routes related to the provision of services using the network configuration within a range limited to the extracted extent of the impact of the failure; and an output unit that identifies and outputs a suitable route as the detour route from among the candidates extracted by the extraction unit based on rules that define suitable routes as the detour route when the specified section is included in the route in which the failure occurred.

2. The network management device according to claim 1, wherein the rule is based on the details of past failures on the route and on appropriate detours assumed from the details of the failures.

3. A network management method performed by a network management device, comprising: an extraction unit of the network management device extracts, when a failure occurs in a specified section of a route in a network configuration, the extent of the impact of the failure in the network configuration due to the occurrence of the failure in the route, and extracts candidates for detour routes for routes related to the provision of services using the network configuration within a range limited to the extracted extent of the impact of the failure; and an output unit of the network management device identifies and outputs an appropriate route as the detour route from among the candidates extracted by the extraction unit, based on rules that define an appropriate route as the detour route when the specified section is included in the route in which the failure occurred.

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