Network management device and method

Abstract

A network management device according to one embodiment of the present invention comprises: an extraction unit that, when a failure has occurred in a communication path of a communication network configuration, extracts a failure influence range resulting from occurrence of the failure in the communication path in the communication network configuration, and extracts candidates for a detour path of the communication path related to provision of service using the communication network configuration within a range limited to the extracted failure influence range; and an output unit that identifies and outputs an appropriate communication path as the detour path 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. 6837022 Japanese Patent No. 7107158 Japanese Patent No. 6655524

[0004] When a failure occurs in a large-scale system, as described above, multiple failure points exist, making it difficult to repair the system in a short time. Therefore, it is necessary not only to understand the current impact, but also to understand the impact of the work on the network after creating a failure recovery procedure. However, impact assessment technology using NOIM (Network Operation Injected Model), a conventional network resource management technology, does not anticipate such a scenario. In fact, to establish and implement a recovery procedure from a failure, technology is needed to understand how the implementation measures will affect the network, i.e., the future situation.

[0005] The impact assessment technology using NOIM described above is intended to assess only the current communication status, and communication path information (hereinafter sometimes referred to as route information), which indicates the order in which each service passes through the nodes on the constructed communication network, is assumed to be obtained taking into account real-time traffic information, etc. Impact assessment logic is constructed using this information. Therefore, it is not possible to simulate communication paths in advance or predict future communication paths.

[0006] As described above, in order to predict future communication paths, a method has been used in which a network simulator provided by a device vendor is used, for example, by locking in to a specific vendor and running a simulation that depends on the specific protocol adopted by that vendor.

[0007] Manually creating route information from design information requires the person in charge to have the skills to understand all of the routing protocols applied to the network, and since it requires a large amount of information and a thorough understanding of the protocols, it is highly dependent on the skill of the person in charge.

[0008] Furthermore, when trying to calculate end-to-end communication routes for the entire network, the scope of calculation becomes significantly broader, making it difficult to manually calculate routes in large-scale networks owned by network operators and composed of multiple vendors.

[0009] As described above, conventional impact assessment technology using NOIM has the following drawbacks: first, it is not possible to perform post-restoration simulations or future route predictions in large-scale networks consisting of multiple vendors owned by a network operator; second, it is not possible to perform route simulations unless all details of each individual protocol used are understood; and third, when calculating communication routes across the entire network, the scope of calculation becomes significantly broader, requiring a long time to calculate the route.

[0010] 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 communication failures.

[0011] A network management device according to one embodiment of the present invention includes an extraction unit that, when a failure occurs in a communication path of a communication network configuration, extracts the extent of the impact of the failure in the communication network configuration due to the failure in the communication path, and extracts candidate detour routes for communication paths related to the provision of services using the communication 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 communication path as the detour route from the candidates extracted by the extraction unit.

[0012] 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 communication path of a communication network configuration, the extent of the failure impact in the communication network configuration due to the failure in the communication path; extracting candidate detour routes for communication paths related to the provision of services using the communication network configuration within a range limited to the extracted extent of the failure impact; and identifying and outputting, by an output unit of the network management device, a suitable communication path as the detour route from among the candidates extracted by the extraction unit.

[0013] According to the present invention, it is possible to appropriately grasp the effect on services caused by the occurrence of a communication failure.

[0014] Fig. 1 is a diagram showing an application example of a network configuration according to an embodiment of the present invention. Fig. 2 is a diagram showing an example of a network configuration after a dummy node is inserted. Fig. 3 is a diagram showing an application example of a network management device according to an embodiment of the present invention. Fig. 4 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. 5 is a block diagram showing an example of the hardware configuration of a network management device according to an embodiment of the present invention.

[0015] An embodiment of the present invention will be described below with reference to the drawings. In one embodiment of the present invention, as a first technique, a route calculation target area is narrowed down based on the impact assessment results. Specifically, the impact assessment results, which are the results of impact assessment performed using NOIM in a state in which the network has been restored from the failure, provide an impact range, which is the range of impact caused by the failure. Then, based on this impact range, the route calculation target area, which is the route redistribution area, i.e., the area for which a detour route for a communication route related to the provision of a service using a communication network configuration is calculated, is limited. Dummy nodes are installed at the boundaries of this area, and static routing is set according to the starting point specified by the user. In this way, by narrowing the route calculation target to the area where the route will be changed, the time required for route calculation can be reduced.

[0016] In one embodiment of the present invention, the second technique involves separating the algorithm into a protocol-generic part and a protocol-specific part by separating the routing protocol in dynamic routing.

[0017] In this technology, various routing protocols used in dynamic routing are classified and generalized into "EGP (Exterior Gateway Protocol)," an exterior gateway protocol, and "IGP (Interior Gateway Protocol)," an interior gateway protocol used in dynamic routing, and these protocols are further separated from the algorithm into a protocol-common part and a protocol-specific part. In this way, by extracting the general-purpose parts of the protocols and creating a route calculation infrastructure that processes them in common, it is possible to minimize the calculation of specific elements that depend on individual protocols.

[0018] In this embodiment, the above technology first makes it possible to simulate the route after repairing the faulty location in advance, before the actual repair is carried out, and calculates the information needed for an operator to theoretically determine the correctness of the recovery plan.

[0019] Second, by separating the common elements and individual elements of protocols, it is possible to separate and standardize only the general-purpose processing for each protocol when considering a route calculation algorithm. Therefore, operators can calculate network route information by simply understanding the individual elements of each protocol and reflecting them in the algorithm.

[0020] Thirdly, by narrowing down the area for route calculation, it is possible to calculate a route within a small area with a small number of devices, thereby reducing the time required to calculate a route.

[0021] 1 is a diagram illustrating an example of a network configuration according to an embodiment of the present invention. Here, an example of a network configuration before virtual node insertion and a fault range are shown. In the example illustrated in FIG. 1, a first VNE (Virtual Network Enabler) "VNE#0", a first GW (gateway) "GW#0", a first CR (Core Router) "CR#0", a first ER (Edge Router) "ER#0", and a first SE (Service Edge) "SE#0" are connected across each layer of the network.

[0022] Also, in the example shown in Figure 1, a second VNE "VNE#1", a second GW "GW#1", a second CR "CR#1", a second ER "ER#1", and a second SE "SE#1" are connected across each stage of the network.

[0023] The NW hierarchical level of each GW is 10, the NW hierarchical level of each CR is 20, the NW hierarchical level of each ER is 30, and the NW hierarchical level of each SE is 40. The larger the value of this NW hierarchical level, the lower the hierarchical level.

[0024] Furthermore, the VNEs are connected to each other, the GWs are connected to each other, the CRs are connected to each other, the EWs are connected to each other, and the SEs are connected to each other. In addition, "10," "20," "30," and "100" shown on the routes of each GW, each CR, and each ER in Fig. 1 indicate the cost level related to setting each route, and in this embodiment, routes are selected so that the total cost is as low as possible.

[0025] In the area consisting of each VNE and each GW, in the area consisting of each CR and each ER (reference symbol a in Figure 1), and in the area consisting of each ER and each SE, route information is redistributed using OSPF (Open Shortest Path First), a type of IGP. In the area consisting of each GW and each CR, route information is redistributed using BGP (Border Gateway Protocol), a type of EGP (reference symbol b in Figure 1). The areas consisting of each GW and each CR and each CR and the area consisting of each CR and each ER, indicated by reference symbol c in Figure 1, are areas within the range of influence caused by a failure, in this case, a failure on the path between "CR#0" and "ER#0" and a failure on the path between "CR#0" and "CR#1".

[0026] Fig. 2 is a diagram showing an example of a network configuration after a dummy node has been inserted. This network configuration is the configuration when a dummy node has been inserted into the configuration shown in Fig. 1. In this embodiment, as the first technique described above, the route calculation target area is narrowed down to the influence range indicated by symbol a in Fig. 2, which is determined based on the NOIM influence assessment results. Note that the route within the non-influence range is not different from the normal case, and is therefore excluded from the route calculation area.

[0027] Dummy nodes are then inserted at both ends of the narrowed-down route calculation target area. As shown in Fig. 2, a static routing protocol is set between the dummy node at the end on the high network hierarchical level side of the route calculation target area and the GW, and the result of this setting is stored in a static route information table, which will be described later. In addition, a static routing protocol is also set between the dummy node at the end on the low network hierarchical level side of the route calculation target area and the ER.

[0028] Within an area consisting of each CR and each ER, route information is redistributed using IGP (symbol b in FIG. 2). Also, within an area consisting of each GW and each CR, route information is redistributed using EGP (symbol c in FIG. 2).

[0029] Next, the creation of a routing table for an IGP node, i.e., route simulation using IGP, which is related to the separation of elements common to IGP protocols and elements specific to each protocol in the second technology described above, will be explained in the following (1-1) to (1-4).

[0030] (1-1) Creating intra-area routes Here, a routing table within an area is created. First, in a link-state routing protocol, which is a type of routing protocol in IGP, the destination with the shortest distance is considered the best path to create the routing table.

[0031] In addition, in a distance-vector routing protocol, which is a type of routing protocol in IGP, a routing table is generated in which the destination route with the smallest cost based on the link state is determined to be the best path for adjacent nodes.

[0032] (1-2) Adding an External Route Here, an external route stored in the IGP external route information table (described later) is added to the routing table generated in (1-1).

[0033] (1-3) Addition to the routing table from protocol-specific elements Here, the best path is updated taking into account the administrative distance specific to the protocol and the method of passing route information, and the route selected as this best path is added and updated to the routing table after processing in (1-2).

[0034] (1-4) Adding a static route Here, a static route is added to the routing table after the processing in (1-3). Next, the creation of a routing table for an EGP node, that is, route simulation by EGP, related to the separation of protocol common elements and individual elements in the second technology, will be explained in the following (2-1) to (2-4).

[0035] (2-1) Generation of Redistribution Route Information Table Here, a redistribution route information table is generated for routes for which route information is redistributed from IGP, Static (static route), or Connected (direct connection) to EGP.

[0036] (2-2) Advertising EGP route information and adding it to the routing table Here, route information is advertised to each EGP peer based on EGP peer information, route information advertised by each router, and EGP policy information. The relevant route information includes the redistribution route information table created in (2-1).

[0037] An EGP peer that receives the advertised route information selects the best path by referring to the values ​​of the set path attributes, and adds the route selected as the best path to the routing table.

[0038] (2-3) Addition to the routing table from protocol-specific elements Here, the best path is updated taking into account protocol-specific path attributes and their priority, and the routing table is added and updated for the route selected as this best path.

[0039] (2-4) Redistribution from EGP to IGP Here, a redistribution route information table is created for routes for which route information is redistributed from EGP to IGP, and external routes are added to this table.

[0040] Next, a general procedure for creating a routing table in a network device will be described in the following (3-1) to (3-4).

[0041] (3-1) Calculation by IGP Here, first, for routing protocols classified as IGP, such as OSPF, the router collects information about the networks to which it is directly connected, and then calculates the optimal route based on this information. This creates an IGP-based routing table.

[0042] Thereafter, the best path is updated taking into consideration protocol-specific settings, such as administrative distance and the method of passing route information, and the route selected as the best path is added to and updated in the routing table.

[0043] (3-2) Calculation by EGP Here, for protocols classified as EGP, such as BGP, the optimal route is calculated based on route information from different organizations, i.e., different AS (Autonomous System) domains, and stored in the EGP route information table, which will be described later. This creates an EGP-based routing table.

[0044] Thereafter, the best path is updated taking into consideration protocol-specific settings, such as path attributes and attribute priorities, and the route selected as the best path is added to and updated in the routing table.

[0045] (3-3) Routing Table Integration Here, routes obtained from different route information sources, i.e., directly connected, static routes, and routing protocols, are integrated. This integration forms the final routing table.

[0046] Next, an overview of the system architecture configuration of the service route prediction function unit will be described. As shown in Fig. 3, the network management device 100 according to this embodiment has a service route prediction function unit 10, a NW resource information DB 20, and an impact assessment function unit 30. The NW resource information DB 20 and the impact assessment function unit 30 are applied to existing NOIM applications.

[0047] The service route prediction function unit 10 includes a configuration reading function unit 11 , a DB 12 , a routing table generation function unit 13 , a route information generation function unit 14 , and a log output function unit 15 .

[0048] DB12 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 route information table.

[0049] The configuration reading function unit 11 reads an input file (reference symbol a in FIG. 3) from the NW resource information D12. This input file includes device configuration information by NOIM, NW design information, and affected path information.

[0050] The configuration reading function unit 11 stores input information based on the input file that has been read in the DB 12 (symbol b in FIG. 3). This input information includes node and interface (IF) information, protocol information, and the like.

[0051] The routing table generation function unit 13 reads the input information stored in the DB 12 (symbol c in FIG. 3 ), generates routing information using the read input information, and stores this in the DB 12 (symbol d in FIG. 3 ).

[0052] The route information generation function unit 14 reads the routing information stored in the DB 12 (symbol e in FIG. 3), uses this routing information to generate route information (symbol f in FIG. 3), and outputs this to the impact understanding function unit 30.

[0053] 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 g in FIG. 3) and outputs this to, for example, an operator.

[0054] In addition, the log output function unit 15 generates log information (symbol h in Figure 3) indicating the access contents to DB12 by the configuration reading function unit 11, routing table generation function unit 13, and route information generation function unit 14, and outputs this to, for example, an operator.

[0055] 4 is a flowchart showing an example of a procedure for processing operations of a network management device according to an embodiment of the present invention. The routing table generation function unit 13 reads a failure-affected service report from the DB 12 and extracts service paths whose service path status is "double-broken" (S11).

[0056] The routing table generation function unit 13 extracts data including the service path extracted in S11 from the device configuration information stored in the DB 12 (S12).

[0057] The routing table generation function unit 13 obtains key information from the data extracted in S12, and based on this key information, obtains data for generating a routing table from DB 12 and excludes information corresponding to the failure location from this data (S13). This key information includes information on the service type, information on the service area, and an identification name for uniquely identifying a combination of these pieces of information. The routing table generation function unit 13 processes the data obtained in S13 for each key to determine the route calculation target area (S14).

[0058] The routing table generating function unit 13 connects a dummy node to the edge of the route calculation target area (S15).

[0059] The routing table generation function unit 13 creates a routing table for when a failure occurs (S16) based on the configuration when the dummy node was connected in S15. This routing table includes, for example, a node information table, an interface information table between nodes, an EGP information table, a static route information table, a route information redistribution information table, and an IGP external route information table.

[0060] The route information generating function unit 14 calculates the optimum route between src and dst, that is, the optimum route in the uplink and downlink directions between the start point of the route and the destination, based on the routing table created in S16 (S17).

[0061] The route information generating function unit 14 generates route information to be used using this optimum route and registers this in the DB 12 (S18).

[0062] After the process of S18, if there is unprocessed data related to the key among the data acquired in S13 (Yes in S19), the process returns to S 14. After the process of S18, if there is unprocessed data related to the key among the data acquired in S13 (No in S19), the route information generation function unit 14 outputs the route information used in the event of a failure (S20).

[0063] The route information generation function unit 14 acquires the start node and end node, information on the up route and down route, and information on the utilization route output section corresponding to the device configuration being processed from the start / end node information table, which is a node information table. The route information generation function unit 14 performs the following processes (4-1) to (4-4) and (5-1) to (5-4) to generate the route information between the acquired start node and end node.

[0064] (Generation of Route Information for Upstream Route) (4-1) The route information generation function unit 14 acquires the node name of the start node in the upstream direction from the node information table, and stores this acquired node name in the internal memory.

[0065] (4-2) The route information generation function unit 14 searches for the next hop node by referring to the routing table of the start node in the uplink direction. The route information generation function unit 14 obtains the node name of the node found in this search from the node information table and stores this obtained node name in its internal memory.

[0066] (4-3) The route information generating function unit 14 repeats the process of (4-2) until the next hop node matches the upstream end node.

[0067] (4-4) When generating a normal utilization route, the route information generation function unit 14 registers the route information stored in the internal memory in the utilization route information table stored in the DB 12 .

[0068] (Generation of Downstream Direction Utilization Route Information) (5-1) The route information generation function unit 14 acquires the node name of the downstream start node from the node information table, and stores this acquired node name in the internal memory.

[0069] (5-2) The route information generation function unit 14 searches for the next hop node by referring to the routing table of the start node in the downlink direction. The route information generation function unit 14 obtains the node name of the node found in this search from the node information table and stores this obtained node name in its internal memory.

[0070] (5-3) The route information generating function unit 14 repeats the process of (5-2) until the next hop node matches the downstream end node.

[0071] (5-4) When generating a utilization route under normal conditions, the route information generation function unit 14 registers the route information held in the internal memory in the utilization route information table stored in the DB 12 .

[0072] 5 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. 5, 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 611A such as a CPU. A program memory 611B, a data memory 612, an input / output interface 613, and a communication interface 614 are connected to this hardware processor 611A via a bus 615.

[0073] The communication interface 614 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.

[0074] An input device 700 and an output device 800 attached to the network management device 100 and used by a user or the like are connected to the input / output interface 613. The input / output interface 613 receives operation data input by a user or the like via the input device 700, such as a keyboard, touch panel, touchpad, or mouse, and outputs output data to an output device 800, which may include a display device using a liquid crystal or organic electroluminescence (EL) display, for display. The input device 700 and the output device 800 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).

[0075] The program memory 611B 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.

[0076] The data memory 612 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.

[0077] The network management device 100 according to an embodiment of the present invention may be configured as an information processing device having software-based processing function units. The storage areas used as work memory and the like by each unit of the network management device 100 may be configured using the data memory 612 shown in FIG. 5 . 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.

[0078] The processing function unit can be realized by having the hardware processor 611A read and execute a program stored in the program memory 611B. However, 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).

[0079] The methods described in each embodiment may be stored as a program (software means) that can be executed by a computer on a recording medium such as a magnetic disk (e.g., a floppy disk, a hard disk, etc.), an optical disk (e.g., a CD-ROM, a DVD, an MO, etc.), or a semiconductor memory (e.g., a ROM, a RAM, a flash memory, etc.), or may be transmitted and distributed via a communication medium. The program stored on the medium also includes a configuration program that configures the software means (including not only executable programs but also tables and 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-described processing by having the operation controlled by 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.

[0080] 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.

[0081] REFERENCE SIGNS LIST 100: Network management device 10: Service route prediction function unit 11: Configuration reading function unit 12: DB 13: Routing table generation function unit 14: Route information generation function unit 15: Log output function unit 20: Network resource information DB 30: Impact understanding function unit

Claims

1. When a failure occurs in a communication path of a communication network configuration, an extraction unit that extracts a failure influence range in the communication network configuration due to the occurrence of the failure in the communication path, and extracts candidates for a detour of the communication path related to the provision of a service using the communication network configuration within a range limited to the extracted failure influence range; and an output unit that identifies and outputs an appropriate communication path as the detour among the candidates extracted by the extraction unit. A network management device comprising the above.

2. The extraction unit extracts the candidates for the detour as candidates for the detour based on elements common to the protocol used inside the extracted failure influence range and the protocol used between the inside and the outside of the extracted failure influence range, candidates for the detour based on elements specific to the protocol used inside, and candidates for the detour based on elements specific to the protocol used between the inside and the outside. The network management device according to claim 1.

3. The extraction unit provides a dummy node at the boundary of the extracted failure influence range, sets a static detour of the communication path related to the provision of a service using the communication network configuration within the failure influence range where the dummy node is provided, and extracts candidates for the detour using the set detour. The network management device according to claim 1.

4. A method performed by a network management device, comprising: extracting, by an extraction unit of the network management device, a failure influence range in the communication network configuration due to the occurrence of a failure in a communication path of the communication network configuration, and extracting candidates for a detour of the communication path related to the provision of a service using the communication network configuration within a range limited to the extracted failure influence range when a failure occurs in the communication path; and identifying and outputting, by an output unit of the network management device, an appropriate communication path as the detour among the candidates extracted by the extraction unit. A network management method comprising the above.

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