JP2009200995A - Apparatus and method for determining detour route - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To speedily save excessive traffic from a link where a link utilization rate is elevated or where congestion occurs. <P>SOLUTION: A detour route determination apparatus 200 includes: an end point candidate extraction means 220 for extracting end point candidates of a detour path on the basis of topology information of a network acquired from a network information collection device 300 and information about a link to be detoured; a traffic communication information acquisition means 230 for acquiring traffic communication information of the link to be detoured from a traffic communication information creation device 500; a detouring traffic volume determination means 240 for determining traffic volume to be detoured for detouring from the link to be detoured on the basis of the traffic communication information of the link to be detoured and a target band; a detour end point determination means 250 for determining a starting point and an ending point of the detour path on the basis of the traffic volume to be detoured and the traffic communication information of the link to be detoured; and a route calculation means 260 for calculating a detour route connecting the starting point and the ending point of the detour path. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for leveling a link utilization rate of a network by saving excess traffic when the link utilization rate increases or congestion occurs in the network.

  Generally, as a dynamic routing protocol for selecting a route of a network such as the Internet, for example, OSPF (Open Shortest Path First) or BGP (Border Gateway Protocol) is used. For example, a technique for performing Internet traffic control by optimizing OSPF weights in consideration of user demand is known (see Non-Patent Document 1). Conventionally, in such a network, when the link utilization rate increases or congestion occurs, the OSPF metric is adjusted to solve the problem and level the link utilization rate of the network. The attribute value (Path Attribute) of BGP is adjusted.

In addition, MPLS (Multi-Protocol Label Switching) is known as a technique that can freely set a route by performing network traffic control. If the link connection of the network for which the route is set is expressed by mesh topology and the MPLS LSP (Label Switched Path) is set to Full Mesh, the link utilization will increase or congestion will occur. When this occurs, it becomes easy to select traffic to be bypassed.
B. Fortz, M. Thorup, “Internet Traffic Engineering by Optimizing OSPF Weights”, INFOCOM2000, Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies, Proceedings, IEEE, vol.2, pp. 519-528

  However, in the case of the conventional method of adjusting the OSPF metric or the attribute value of BGP, it is necessary to perform a very complicated calculation, which causes the following problems. That is, when determining a metric or the like based on the judgment of the network operator, it takes a long time to complete the setting because it involves manual work. In addition, when automatically calculating a metric or the like, it takes a long time to calculate an optimum value.

  In addition, when the MPLS LSP is set to a full mesh, the number of LSPs to be set is larger than when the full mesh is not used. The number of LSPs increases geometrically as the number of network nodes increases. Therefore, it takes time to manage the LSP, and it cannot be applied to a large-scale network.

  Therefore, an object of the present invention is to solve the above-described problems and provide a technique capable of quickly evacuating excess traffic from a link with an increased link utilization rate or a link with congestion.

  In order to solve the above-mentioned problem, the detour route determination device according to claim 1 obtains network traffic information and topology information from each network node constituting the network, and link utilization rate increases or congestion occurs. A network information collection device that detects one or more consecutive links as a bypass target link, a traffic exchange information creation device that creates traffic exchange information related to traffic using the bypass target link, and the bypass target link A detour route determination device of a communication system comprising a detour route determination device that determines a detour route for detouring a part of the traffic being performed, and a detour path setting device that newly sets a path in the detour route, Network topology acquired from the network information collection device And using the detour target link from the end point candidate extracting means for extracting network node information as detour start point candidates and end point candidates based on the detour and the information on the detour target link, and the traffic exchange information creating device. Traffic exchange information acquisition means for acquiring traffic exchange information relating to traffic that is being trafficked, traffic exchange information relating to traffic that is using the bypass target link, and target bandwidth, based on traffic exchange information and target bandwidth of the traffic that is using the bypass target link Based on the detour target traffic volume determining means for determining the detour target traffic volume indicating the traffic volume of the detour, and the traffic exchange information regarding the determined detour target traffic volume and the traffic using the detour target link, Said detour A detour end point determining means for determining a start point and an end point, and a route calculation means for determining the detour path by calculating a path connecting the start point and the end point of the determined detour. And

  Further, in order to solve the above problem, the detour route determination method according to claim 6, wherein the network traffic information and the topology information are acquired from each network node constituting the network, and the link utilization rate has increased or congestion has occurred. Network information collection device that detects one or more continuous links in which traffic has occurred as a bypass target link, a traffic exchange information creation device that creates traffic exchange information related to traffic using the bypass target link, and the bypass target link A detour by the detour route determination device of a communication system including a detour route determination device that determines a detour route that bypasses a part of the traffic that uses the network and a detour path setting device that newly sets a path in the detour route A route determination method, wherein the detour route determination device has a traffic. A evacuation request accepting unit; an endpoint candidate extracting unit; a traffic exchange information acquiring unit; a detour target traffic amount determining unit; a detouring end point determining unit; a route calculating unit; and a detour path setting requesting unit; By the request accepting unit, obtaining information on the detour target link from the network information collecting device together with a traffic saving request, obtaining the network topology information from the network information collecting device, and the endpoint candidate extracting unit, Based on the information about the detour target link and the topology information of the network, the node candidate extraction step of extracting information on the network node as a detour start point candidate and an end point candidate, and the traffic exchange information acquisition means Traffic exchange information acquisition step for obtaining traffic exchange information related to traffic using the bypass target link from the information creation device, and traffic related to traffic using the bypass target link by the bypass target traffic amount determination means Based on the AC information and the target band, the detour target traffic amount determining step for determining the detour target traffic amount indicating the traffic amount to be detoured among the traffic using the detour target link, and the detour end point determining means, A detour end point determining step for determining a start point and an end point of the detour based on the determined detour target traffic amount and traffic exchange information regarding traffic using the detour target link, and the route calculation means, Said And performing a route calculation step of determining the detour route by calculating a route that connects the start point and the end point of the determined detour route.

  According to the detour route determination device according to claim 1 or the detour route determination method according to claim 6, when the detour route determination device acquires information about the detour target link in the network, the detour route determination device uses the network topology information. Extract start point candidates and end point candidates of the detour. Then, the detour route determination device determines the detour target traffic amount based on the traffic actually using the detour target link and the target bandwidth. Then, the detour route determination device determines an optimum detour start point and end point from among detour start point candidates and end point candidates based on the detour target traffic volume and actual AC traffic information, and between the start point and the end point Calculate the route. Based on this, the detour path setting device sets a path for the detour path. Therefore, the detour route determination device calculates a route for the route between the start point and the end point determined in the entire network according to the link usage status when the detour target link is detected. A detour route that can be evacuated can be quickly determined.

  Further, the detour route determination device according to claim 2 is the detour route determination device according to claim 1, wherein the route calculation means acquires the topology information and traffic information of the network from the network information collection device. Then, from the acquired topology information of the network, create topology information for route calculation by removing the link in the link usage state that cannot accommodate the amount of traffic to be bypassed, and using the created topology information for route calculation, The shortest route from the start point to the end point of the detour route is calculated as the detour route, and when the shortest route is not obtained, the detour end point determining means is determined to determine the start point and end point of a new detour route. Is required.

  Further, the detour route determination method according to claim 7 is the detour route determination method according to claim 6, wherein the detour route determination device performs the network information by the route calculation means before the route calculation step. An information acquisition step of acquiring topology information and traffic information of the network from a collection device, and a topology for path calculation in which a link in a link usage state that cannot accommodate the amount of detour target traffic is removed from the acquired topology information of the network A calculation topology information creation step for creating information, and using the created topology information for route calculation in the route calculation step, the shortest route from the start point to the end point of the bypass route is If the shortest route is not obtained when calculated as a route, the detour end The determination means, by said detour endpoint determining step, and determining the start and end points of the new detour.

  According to the detour route determination device according to claim 2 or the detour route determination method according to claim 7, the detour route determination device is used for route calculation in which a link in a link usage state that cannot accommodate a detour target traffic amount is removed. Since the topology information is created and the shortest route is calculated, the number of network nodes required to calculate the shortest route is reduced and the shortest route is faster than when the acquired network topology information is used as it is. Can be calculated. Moreover, even if the shortest route cannot be obtained at a time, the shortest route can be calculated using the newly acquired start point and end point.

  A detour route determination device according to claim 3 is a detour route determination device according to claim 1 or claim 2, wherein the detour route determination device indicates that the detour target link has been detected from the network information collection device. Evacuation request accepting means for obtaining the network topology information and traffic information, and calculating the link utilization rate of the entire network as the target bandwidth based on the obtained network topology information and traffic information. It is characterized by that.

  Further, the detour route determination method according to claim 8 is the detour route determination method according to claim 6 or claim 7, wherein the detour route determination device uses the traffic save request accepting unit to execute the network information collection device. A target bandwidth calculating step of calculating a link utilization rate of the entire network as the target bandwidth based on the topology information and traffic information of the network acquired from the network is further executed.

  According to the detour route determination device according to claim 3 or the detour route determination method according to claim 8, the detour route determination device receives the traffic save request, and then obtains the latest network topology information and traffic information. The target bandwidth that is obtained and reflects the latest network usage status can be calculated. Therefore, by using the calculated target bandwidth, it is possible to determine an optimum detour route that can save excess traffic according to the current link usage status.

  Further, the detour route determination device according to claim 4 is the detour route determination device according to any one of claims 1 to 3, wherein route information of the detour route determined by the route calculation unit is acquired. And obtaining the network topology information from the network information collection device, and calculating the determined detour path metric from the acquired network topology information so that the metric is smaller than the detour source path. , A detour path setting request, a detour path setting information, route information of the detour path, and a path information of the detour path, which sets a path of MPLS (Multi-Protocol Label Switching) or GMPLS (Generalized Multi-Protocol Label Switching), A detour path setting request means for notifying detour path metric information is further provided.

  Further, the detour route determination method according to claim 9 is the detour route determination method according to any one of claims 6 to 8, wherein the detour route determination device is configured so that the detour path setting request unit includes: From the network topology information acquired from the network information collection device, the metric of the detour route determined in the route calculation step is calculated so that the metric is smaller than the detour source route, and MPLS or GMPLS of the detour path is calculated. A detour path setting request step for notifying a detour path setting device for setting a path, a detour path setting request, route information of the detour route determined in the route calculation step, and metric information of the detour route. Furthermore, it is characterized by executing.

  According to the detour route determination device according to claim 4 or the detour route determination method according to claim 9, the detour route determination device sets a detour path for the detour path setting device that sets an MPLS or GMPLS path. The request, the route information of the detour route, and the metric information of the detour route are notified. Therefore, the detour path setting device that has received the notification sets the detour path using the detour path information and the metric information, thereby saving excess traffic of the detour target link. Furthermore, by applying this detour route determination device to a network in which an existing detour path setting device for setting an MPLS or GMPLS path is installed, the device cost can be suppressed.

  Further, the detour route determination device according to claim 5 is the detour route determination device according to any one of claims 1 to 3, wherein route information of the detour route determined by the route calculation unit is acquired. The detour path setting request and the determined detour path are sent to either a detour path setting device that sets static routing as a detour path or a detour path setting device that sets packet marking as a detour path. The apparatus further comprises a detour path setting request means for notifying route information.

  Further, the detour route determination method according to claim 10 is the detour route determination method according to any one of claims 6 to 8, wherein the detour route determination device is configured to use the detour path setting request unit. A detour path setting request and a detour determined in the route calculation step for either a detour path setting device that sets static routing as a detour path or a detour path setting device that sets packet marking as a detour path A detour path setting request step for notifying route information of the route is further executed.

  According to the detour route determination device according to claim 5 or the detour route determination method according to claim 10, the detour route determination device is a detour path setting device that sets static routing, or a detour that sets packet marking. A bypass path setting request and route information of the bypass path are notified to any path setting device. Therefore, the bypass path setting device that has received the notification sets the bypass path using the route information of the bypass path, so that excessive traffic on the bypass target link can be saved. Further, the detour route determination device does not need to calculate the detour route metric information, so that the processing load can be reduced and the detour path setting request can be notified quickly.

  ADVANTAGE OF THE INVENTION According to this invention, the detour route determination apparatus can determine rapidly the detour route which saves excess traffic according to the link utilization condition when a detour target link is detected. Therefore, the present invention can be applied to a large-scale network, and the link utilization rate of the network can be leveled at a high speed when the link utilization rate increases or when congestion occurs.

  The best mode (hereinafter referred to as “embodiment”) for carrying out the detour route determination device and the detour route determination method of the present invention will be described below in detail with reference to the drawings. Here, the configuration of a communication system including the detour route determination device of the present invention, then an example of a link whose link utilization rate has increased or a link in which congestion has occurred (a detour target link), and an excessive amount from the detour target link The configuration of each device of the communication system including the detour route determination device that quickly evacuates traffic, and finally the operation of the entire communication system will be sequentially described.

[Communications system]
FIG. 1 is a diagram illustrating an overall configuration of a communication system in which excessive traffic is saved. As shown in FIG. 1, the communication system 1 includes a backbone network 2 operated by a network operator and a plurality of user networks 3 (3a, 3b, 3c, 3d, 3e, 3f operated by general users (users). , 3g, 3h, 3i, 3j). In the present embodiment, it is assumed that the backbone network 2 and each user network 3 have a communication device based on IP (Internet Protocol) and can communicate using IP. The communication system 1 can also be realized by a network configured by IPv6 (Internet Protocol Version 6) or the like.

  The backbone network 2 is configured by a broadband link, and the network path is managed by the OSPF protocol or the BGP protocol. In the present embodiment, it is assumed that a traffic route can be freely designed by MPLS or GMPLS. The backbone network 2 includes network nodes 101, 102, 103, 104, 105, 106, 107, and 108. The backbone network 2 and each user network 3 are connected by edge routers 111, 112, 113, 114, 115, 116, 117, and 118. The network node and the edge router are devices including, for example, an optical cross connect (OXC), a router, and a switch. The numbers of the network nodes, edge routers, and user networks are not particularly limited.

  The user network 3 includes a LAN (Local Area Network) network cable (not shown) such as Ethernet (registered trademark), a network hub (not shown), a router (not shown), and a user edge (not shown). Connected) to each interface (not shown).

  The communication system 1 includes a detour route determination device 200, a network information collection device 300, a detour path setting device 400, and a traffic exchange information creation device 500. The detour route determination device 200, the network information collection device 300, the detour path setting device 400, and the traffic exchange information creation device 500 are, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory (HDD), Hard Disk Drive (HDD), NIC (Network Interface Card) for communication, and the like are provided.

  The bypass route determination device 200 determines a bypass route that bypasses a part of the traffic that uses the bypass target link detected by the network information collection device 300.

  The network information collection device 300 acquires network traffic information and topology information from each of the network nodes 101 to 108, and detects one or more continuous links where the link utilization rate has increased or congestion has occurred as a bypass target link. To do.

  The detour path setting device 400 newly sets a path to the detour route determined by the detour route determination device 200. In the present embodiment, the bypass path setting device 400 sets an MPLS or GMPLS path as the bypass path.

  The traffic exchange information creation device 500 creates traffic exchange information related to traffic using the detour target link detected by the network information collection device 300. The traffic exchange information indicates not only traffic information in one direction but also traffic information including traffic information in the other direction.

[Example of bypass target link]
Next, an example of a detour target link handled by the detour route determination device 200 according to the embodiment of the present invention will be described with reference to FIGS. 6 and 7. FIG. 6 is a configuration diagram illustrating an example of a detour target link, and FIG. 7 is an explanatory diagram illustrating an example of a method of determining detour target traffic by the detour route determination device. In the example of FIG. 6, it is assumed that a link connecting two nodes (a congestion start point 601 and a congestion end point 602) is a detour target link. Here, specifically, for a link connecting these two nodes (congestion start point 601 and congestion end point 602), for example, a bandwidth of 1 Gbps is set as the maximum bandwidth of the link. In this example, 1.2 Gbps traffic exceeding the maximum bandwidth is used for this link. Further, it is assumed that the detour target traffic amount (target bandwidth) acquired by the detour endpoint determination unit 250 is 500 to 700 Mbps.

  The traffic path using the congestion link (the bypass target link) 603 includes a tree structure having a congestion start point 601 as a vertex (root) upstream (one side) of the congestion link 603 and a downstream (other side) of the congestion link 603. It can be expressed as a tree structure having a congestion end point 602 as a vertex (root). For the purpose of detecting the start point and the end point corresponding to the amount of traffic to be diverted (the amount of traffic to be detoured) out of the traffic that may use the congestion link 603, the detour route determination device 200 first determines a detour start point candidate and The tree structure shown in FIG. 6 is used to set the end point candidate. The detour route for which the route is calculated is referred to as a detour route. That is, in the case of a detour, it is assumed that only the end point (detour end point) indicating the start point or the end point is determined, and the route has not yet been calculated.

  The first starting point candidate as a candidate to be a detour end point is a node indicated by symbol A in FIG. 6 (hereinafter referred to as “node A”) and a node indicated by symbol B in FIG. 6 (hereinafter referred to as “node B”). It is. Similarly, the first end point candidates are “node C” and “node D”. The detour route determination device 200 adds all nodes one layer below in the tree as the next start point candidate and end point candidate. That is, the starting point candidates to be added are “node A-1”, “node A-2”, “node A-3”, “node B-1”, and “node B-2”. Similarly, the end point candidates added to the next hierarchy are “node D-1” and “node D-2”. Further, the starting point candidates added to the lower hierarchy are “node A-1-1”, “node B-1-1”, and “node B-1-2”.

  The detour route determination device 200 (a detour end point determination unit 250 described later) performs the following processing. That is, the detour route determination device 200 divides the traffic matrix shown in FIG. 7 in accordance with the processing for searching the tree structure shown in FIG. Then, the detour route determination device 200 determines whether there is traffic suitable for evacuation among all the opposite end point candidates (or start point candidates) that are paired with the added start point candidate (or end point candidate). Explore. In this example, it is assumed that the traffic suitable for evacuation is set as 500 to 700 Mbps indicating the target bandwidth of the detour path after the evacuation process (the path set for the detour path). In the example of FIG. 7, the bandwidth (amount of AC traffic) used by traffic starting from the starting point candidate “node A-1-1” and ending at the end point candidate “node C” is 100 Mbps. Further, the AC traffic volume starting from the starting point candidate “Node A-1-1” and ending at the end point candidate “Node D-1” is 200 Mbps. Similarly, in FIG. 7, the band (AC traffic amount) is described as a total of 18 matrix elements.

  The total value of the bands indicated by the six matrix elements indicated by reference numeral 701 is 560 Mbps. The total value of the bands is included in the target band (500 to 700 Mbps) from the relationship of 500 <560 <700. Therefore, in the example shown in FIG. 7, the traffic from the congestion start point “Node B-1” to the congestion end points “Node C, Node D-1, and Node D2” corresponds to the detour target traffic amount (target bandwidth). It will be. As a result, “Node B-1” is determined as the start point of the detour. Further, “node C, node D-1, and node D2” are determined as the end points of the detour. From the information of the start point and end point of this detour, a route connecting these is calculated and the detour route is determined. Then, a path is set in this detour route (detour path), and excess traffic can be quickly evacuated from the congestion link 603 (detour target link).

  In this way, for example, as a device that realizes a function of quickly evacuating excess traffic from the congestion link 603 (a detour target link), a detour route determination device 200, a network information collection device 300, and a detour path setting device 400 are described below. A detailed configuration of the traffic exchange information creation device 500 will be described.

[Alternative route determination device]
FIG. 2 is a block diagram schematically showing an example of the detour route determination device according to the embodiment of the present invention. The detour route determination device 200 includes an evacuation request reception unit 210, an end point candidate extraction unit 220, a traffic exchange information acquisition unit 230, a detour target traffic amount determination unit 240, a detour end point determination unit 250, and a route calculation unit 260. And detour path setting requesting means 270.

<Evacuation request accepting means>
The save request accepting unit 210 accepts a traffic save request indicating that the detour target link is detected from the network information collecting apparatus 300. In the present embodiment, the evacuation request accepting unit 210 receives a traffic evacuation request notification from the network information collection device 300. Here, the bypass target link not only indicates one link between two adjacent network nodes but also means two or more continuous links. Note that the save request accepting unit 210 may be configured to inquire regularly or irregularly about whether or not the detour target link is detected to the network information collecting apparatus 300.

  In the present embodiment, the evacuation request accepting unit 210 starts a detour route determination procedure when receiving a traffic evacuation request and information related to a detour target link. Specifically, the evacuation request accepting unit 210 requests the following processing operation from the end point candidate extracting unit 220, the traffic exchange information acquiring unit 230, the detour target traffic amount determining unit 240, and the detour end point determining unit 250.

  The evacuation request reception unit 210 notifies the end point candidate extraction unit 220 of information related to the detour target link and requests acquisition of the end point candidate information (outputs the end point candidate information request). The end point candidate information indicates information of a pair of network nodes (edge node information) indicating a start point and an end point of traffic using the detour target link, and information of a start point candidate and an end point candidate serving as a detour.

  The evacuation request reception unit 210 notifies the traffic exchange information acquisition unit 230 of the endpoint candidate information and requests acquisition of traffic exchange information related to traffic using the detour target link (traffic exchange information acquisition request). Output).

  The evacuation request reception unit 210 notifies the detour target traffic volume determination unit 240 of information related to the detour target link and requests the detour target traffic volume determination (outputs a detour target traffic volume determination request). The detour target traffic amount indicates the traffic amount to be detoured among the traffic using the detour target link.

  The evacuation request reception unit 210 notifies the detour end point determination unit 250 of the detour target traffic amount and requests the detour end point determination (outputs the detour end point determination request).

  In the present embodiment, the save request accepting unit 210 acquires network topology information and traffic information from the network information collection device 300, and based on the acquired network topology information and traffic information, the link utilization rate of the entire network. As a target bandwidth. The calculated target band is stored in the target band DB 290. Note that a method for acquiring network topology information and traffic information in order to calculate the target bandwidth is arbitrary. In the following, in the case of acquisition, passively receiving notification from the acquisition source device regularly or irregularly, and actively requesting acquisition of information from the acquisition destination device periodically or irregularly Both are included.

<Endpoint candidate extraction means>
The end point candidate extracting unit 220 extracts information on the network nodes 101 to 108 as detour start point candidates and end point candidates based on the network topology information acquired from the network information collection device 300 and information on the detour target link. It is. The endpoint candidate extraction unit 220 requests network topology information from the network information collection device 300 when receiving the endpoint candidate information request and the information about the detour target link from the save request reception unit 210 (network topology information). Output request). The endpoint candidate extraction means 220 extracts the endpoint candidate information as information indicating which traffic between grounds uses the detour target link by using the acquired network topology information (simply referred to as topology information), This is notified to the evacuation request reception unit 210. In the present embodiment, the endpoint candidate extraction unit 220 is configured such that all the network nodes located upstream (one side) from the detour target link in the middle route of the traffic using the detour target link are candidates for the detour start point, All network nodes located downstream (the other side) from the detour link are defined and extracted as candidates for detour end points. In the evacuation request accepting unit 210, all network nodes located upstream from the detour target link are all defined as candidate detour start points, and all network nodes located downstream from the detour target link are all defined as detour end point candidates. The terminal candidate information request may be output.

<Traffic exchange information acquisition means>
The traffic exchange information acquisition unit 230 acquires traffic exchange information related to traffic using the detour target link from the traffic exchange information creation device 500. The traffic exchange information acquisition unit 230 receives the traffic exchange information acquisition request and the end point candidate information from the evacuation request reception unit 210, notifies the traffic exchange information creation device 500 of the end point candidate information, and detour target link. Request traffic exchange information related to traffic using. (Output traffic traffic information request). The traffic exchange information acquisition unit 230 records the acquired traffic exchange information and endpoint candidate information in the traffic exchange information DB 280.

<Detour target traffic volume determination means>
The detour target traffic amount determination unit 240 indicates the detour target traffic indicating the traffic amount to be detoured among the traffic using the detour target link based on the traffic exchange information regarding the traffic using the detour target link and the target band. The amount is to be determined. The detour target traffic volume determination unit 240 receives the detour target traffic volume determination request and information related to the detour target link from the evacuation request reception unit 210. In the present embodiment, the detour target traffic volume determination means 240 flows to the detour target link using information related to the detour target link and information stored in the traffic exchange information DB 280 (traffic exchange information, endpoint candidate information). Identify traffic volume (traffic exchange information). The detour target traffic volume determination unit 240 acquires the target band set for the detour target link from the target band DB 290, determines the detour target traffic volume from the acquired target band and the specified traffic volume, and saves it. The request reception unit 210 is notified. In addition, as shown by a broken line in FIG. 2, the detour target traffic volume determination unit 240 uses a configuration notified from the network information collection device 300 without uniquely specifying the traffic volume (traffic exchange information). You can also

<Detour endpoint determination means>
The detour end point determination unit 250 determines a start point and an end point of the detour based on the detour target traffic amount determined by the detour target traffic amount determination unit 240 and the traffic exchange information regarding the traffic using the detour target link. To do. The detour end point determination unit 250 receives the detour end point determination request and the detour target traffic amount information from the evacuation request accepting unit 210, and matches the detour target traffic amount with reference to the traffic exchange information stored in the traffic exchange information DB 280. The start point and end point pair to be found is found, and the start point and end point of the detour are determined. The detour end point determination unit 250 can specify the traffic amount between the selected nodes by selecting one node between the start point candidate and the end point candidate of the detour in the traffic exchange information DB 280. The detour end point determination unit 250 notifies the route calculation unit 260 of the information on the start and end points of the detour and the information on the amount of traffic to be detoured, and requests the calculation of the route (outputs a route calculation request). To do).

<Route calculation means>
The route calculation unit 260 determines a detour route by calculating a route that connects the start point and the end point of the detour determined by the detour end point determination unit 250. The route calculation unit 260 receives the route calculation request, the information on the start and end points of the detour, and the information on the amount of traffic to be detoured from the detour end point determination unit 250, and sends the network topology information to the network information collection device 300. And request information about traffic (send topology traffic information request).

  In addition, the route calculation unit 260 acquires network topology information and traffic information (topology / traffic information) from the network information collection device 300, and the link usage state in which the detour target traffic amount cannot be accommodated from the acquired network topology information. Create topology information for route calculation with the link removed. The route calculation means 260 calculates the shortest route from the start point to the end point of the detour route as a detour route using the created topology information for route calculation. If the shortest route is not obtained, a new detour route is calculated. The detour end point determination means 250 is requested to determine the start point and the end point of. Here, the method for calculating the shortest path is arbitrary, and for example, a Dijkstra algorithm can be used. When the shortest route is obtained, the route calculation unit 260 notifies the detour path setting request unit 270 of the detour path route information and requests the detour path setting (output a detour path setting request). To do).

<Bypass path setting request means>
The detour path setting request unit 270 acquires route information of the detour route determined by the route calculation unit 260, acquires network topology information from the network information collection device 300, and acquires the detour source information from the acquired network topology information. The metric of the detour route determined by the route calculation unit 260 is calculated so that the metric is smaller than the route, and the detour path setting request, the detour route information, the detour route information, Notification of metric information. The bypass path setting request unit 270 receives the bypass path setting request and the route information of the bypass route from the route calculation unit 260, and requests network topology information from the network information collection device 300 (transmits a topology information request). ).

<Traffic exchange information DB>
The traffic exchange information DB 280 is a database that stores traffic exchange information that is updated by the traffic exchange information acquisition unit 230 and is used by the detour endpoint determination unit 250.

<Target bandwidth DB>
The target bandwidth DB 290 is a database that stores, as a target bandwidth, a traffic amount or a link usage rate after removing a detour target traffic amount that is determined in advance for the entire network, a group unit, or a link unit. In the present embodiment, the target bandwidth stored in the target bandwidth DB 290 is automatically calculated by the save request receiving means 210 according to the network topology information and traffic information. The traffic exchange information DB 280 and the target bandwidth DB 290 are stored in, for example, a general hard disk.

  Note that the evacuation request accepting unit 210, the end point candidate extracting unit 220, the traffic exchange information acquiring unit 230, the detour target traffic amount determining unit 240, the detour end point determining unit 250, the route calculating unit 260, and the detour path setting request unit 270 are processed by the CPU. This is realized by developing a predetermined program stored in the storage means in the RAM and executing it.

[Network information collection device]
FIG. 3 is a block diagram schematically showing an example of the network information collecting apparatus shown in FIG. As shown in FIG. 3, the network information collection device 300 includes network information collection means 310, network information notification means 320, topology information DB 330, and traffic information DB 340.

<Network information collection means>
The network information collecting means 310 connects to the network nodes 101 to 108 in the backbone network 2 using, for example, OSPF, BGP, SNMP (Simple Network Management Protocol), CLI (Command Line Interface), etc. The traffic information is acquired, the acquired topology information is stored in the topology information DB 330, and the acquired traffic information is stored in the traffic information DB 340.

  Here, the network information collecting unit 310 can periodically collect information using SNMP in order to obtain the topology information from the network nodes 101 to 108.

  Further, the network information collecting unit 310 can acquire topology information by receiving notifications periodically or when there is a change, using OSPF or BGP.

  In addition, when there is a change in the backbone network 2, the network information collecting unit 310 may receive notification of a change in network information by receiving a trap (for example, coldStart Trap, linkDown Trap, linkUp Trap). it can.

  Further, the network information collecting unit 310 can periodically acquire information on traffic from the network nodes 101 to 108 using SNMP, Net Flow, nFlow, or the like. Net Flow and nFlow are traffic management technologies developed by Cisco Systems, Inc. in the United States.

  Further, the network information collecting unit 310 actively requests and collects information from the network nodes 101 to 108, or passively receives notifications such as traps from the network nodes 101 to 108, whereby the backbone information is collected. An increase in link utilization and congestion in the network 2 are detected. The network information collection unit 310 sets a link in which an increase in link utilization rate or congestion is detected as a detour target link, and notifies the detour route determination device 200 of a traffic save request and detour target link information.

<Network information notification means>
The network information notification unit 320 receives a topology information request, a traffic information request, and a topology / traffic information request from the detour route determination device 200 and the traffic exchange information creation device 500, and receives the requested information from the topology information DB 330 and the traffic information DB 340. Read and notify. In some cases, the network information notifying unit 320 receives the information conditions of the topology information request, the traffic information request, and the topology / traffic information request, and only the information corresponding to the received condition is received from the topology information DB 330 and the traffic information DB 340. There may be a read notification.

<Topology information DB>
The topology information DB 330 is a database that is updated by the network information collecting unit 310 and stores information on the network topology (network topology information).

<Traffic information DB>
The traffic information DB 340 is a database that is updated by the network information collecting unit 310 and stores information relating to network traffic (traffic exchange information and the like). The topology information DB 330 and the traffic information DB 340 are stored in, for example, a general hard disk.

[Bypass path setting device]
FIG. 4 is a block diagram schematically illustrating an example of the detour path setting device illustrated in FIG. The detour path setting device 400 includes path setting means 410. The path setting unit 410 receives a detour path setting request, detour path path information, and detour path metric information from the detour path determination apparatus 200, and uses RSVP (Resource reSerVation Protocol), CLI, etc. An MPLS or GMPLS path is set between specified grounds (between network nodes), and a specified metric is given to the set path. The detour path setting device 400 can be configured to acquire information (traffic volume) regarding detour traffic together with the detour path setting request. Further, the bypass path information can correspond to one or a plurality of bypass paths.

[Traffic exchange information creation device]
FIG. 5 is a block diagram schematically showing an example of the traffic exchange information creation device shown in FIG. The traffic exchange information creation device 500 includes traffic exchange information creation means 510. The traffic exchange information creation unit 510 receives a traffic exchange information request and end point candidate information from the detour route determination device 200. The traffic exchange information creating unit 510 requests the network topology information and traffic information from the network information collection device 300 or obtains it by receiving a notification. The traffic exchange information creation unit 510 creates traffic exchange information using the end point candidate information, the network topology information and information related to traffic, and notifies the detour route determination apparatus 200 of the traffic exchange information. The traffic exchange information creation unit 510 receives the traffic exchange information request and the information about the detour target link from the detour route determination device 200, and uses the information about the detour target link, the network topology information, and the information about the traffic. Then, traffic exchange information may be created.

[Overall operation of communication system]
Implementation of saving excess traffic in the communication system shown in FIG. 1 will be described with reference to FIG. 8 (see FIGS. 1 and 2 as appropriate). FIG. 8 is a sequence diagram showing saving of excess traffic by the detour route determination method according to the embodiment of the present invention. Assume that the network information collecting apparatus 300 collects network information (topology information, traffic information) from the network nodes 101 to 108 of the backbone network 2 in advance (step S1). Further, it is assumed that the detour route determination device 200 calculates the target bandwidth using the current network information and stores it in the target bandwidth DB 290 (step S2: target bandwidth calculation step).

  When the network information collection device 300 detects a congestion link (a bypass target link) (step S3), the network information collection device 300 transmits a traffic save request together with information on the bypass target link to the bypass route determination device 200 (step S4). When the detour request receiving unit 210 receives the traffic save request (step S5: traffic save request receiving step), the detour route determination device 200 receives the topology information from the end point candidate extraction unit 220 to the network information collection device 300. A request is transmitted (step S6).

  When receiving the topology information request (step S7), the network information collection device 300 transmits the network topology information to the detour route determination device 200 (step S8). The detour route determination device 200 receives the topology information of the network by the end point candidate extraction unit 220 (step S9: topology information acquisition step), and the end point candidate (endpoint candidate information) for the detour target link based on the topology information of the network. ) Is extracted (step S10: endpoint candidate extraction step). Then, the detour route determination apparatus 200 transmits a traffic exchange information request together with the endpoint candidate information to the traffic exchange information creation apparatus 500 by the traffic exchange information acquisition unit 230 (step S11).

  When receiving the traffic exchange information request (step S12), the traffic exchange information creation device 500 transmits a topology / traffic information request to the network information collection device 300 (step S13). When receiving the topology / traffic information request (step S14), the network information collecting apparatus 300 transmits the topology / traffic information read from the topology information DB 330 and the traffic information DB 340 to the traffic exchange information creating apparatus 500 (step S15).

  When receiving the topology / traffic information (step S16), the traffic exchange information creating apparatus 500 creates traffic exchange information indicating the traffic using the detour target link (step S17). Then, the traffic exchange information creation device 500 transmits the created traffic exchange information to the detour route determination device 200 (step S18). The detour route determination device 200 receives the traffic exchange information of the detour target link by the traffic exchange information acquisition unit 230 (step S19: traffic exchange information acquisition step).

  Then, the detour route determination device 200 determines the detour target traffic amount with reference to the traffic exchange information DB 280 and the target bandwidth DB 290 by the detour target traffic amount determination means 240 (step S20: detour target traffic amount determination step). In the detour route determination device 200, the detour end point determination unit 250 determines the detour start point and end point (detour end point) from the detour start point candidate and end point candidate based on the detour target traffic amount ( Step S21: detour end point determination step).

  Then, the detour route determination device 200 transmits a topology information request to the network information collection device 300 by the route calculation unit 260 (step S22). When the network information collection device 300 receives the topology information request (step S23), the network information collection device 300 transmits the topology information read from the topology information DB 330 and the traffic information DB 340 and information about the traffic to the detour route determination device 200 (step S24). Then, the detour route determination apparatus 200 performs the following operation by the route calculation unit 260. That is, the route calculation means 260 receives topology information and information related to traffic (step S25: information acquisition step). Then, the route calculation means 260 creates topology information for calculation by removing links that are not used for calculation from the received topology information (step S26: calculation topology information creation step). Then, the route calculation means 260 calculates the shortest route connecting the start and end points of the detour using the created topology information for calculation (step S27: route calculation step).

  If the shortest route cannot be obtained in step S27, the detour route determination device 200 returns to step S21. On the other hand, when the shortest route is obtained in step S27, the detour route determination device 200 calculates the detour route metric by the detour path setting request unit 270, and detours along with the detour route route information and metric information. A path setting request is transmitted to the detour path setting device 400 (step S28: detour path setting request step). When the detour path setting device 400 receives the detour path setting request (step S29), the detour path setting apparatus 400 sets a detour path based on the path information and metric information of the detour path (step S30).

  According to the present embodiment, the detour route determination device 200 first extracts a detour start point candidate and an end point candidate from the topology information of the network when the link utilization rate increases or congestion occurs in the backbone network 2. Then, based on the traffic using the detour target link and the target bandwidth, the detour target traffic amount is determined. Subsequently, the detour route determination device determines an optimum detour start point and end point based on the detour target traffic amount and the AC traffic information, and determines a detour route by calculating a route between the start point and the end point. . Accordingly, the detour route determination apparatus 200 calculates a route between the start point and the end point of the detour route determined in the entire network according to the link usage status when the detour target link is detected. Can be determined quickly. Therefore, the detour path setting device 400 can quickly set a path for this detour path. Therefore, excess traffic can be quickly evacuated from the detour target link. As a result, the network link utilization rate can be leveled at high speed.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can implement in the range which does not change the meaning. For example, in the present embodiment, the target bandwidth stored in the target bandwidth DB 290 of the detour route determination device 200 is automatically calculated by the save request accepting unit 210 according to the network topology information and traffic information. However, it can be set, for example, by a network operator inputting in advance or periodically or irregularly updating input. As an input method in this case, the network operator can input via a network using protocol communication such as FTP (File Transfer Protocol). Further, the network operator directly inputs to the detour route determination device 200 using an input device (keyboard, mouse, scanner, etc.) and a storage medium (flexible disk, CD-ROM (Compact Disk Read Only Memory), flash memory, etc.). You can also

  In the present embodiment, the bypass path setting device 400 sets an MPLS or GMPLS path as the bypass path, and the bypass path setting request unit 270 of the bypass route determination device 200 responds to this by setting a bypass path. Although the route metric is calculated and the bypass route metric is transmitted to the bypass path setting device 400 together with the route information of the bypass route, the present invention is not limited to this. In the following, variations of the detour path setting request unit 270 of the detour path setting device 400 and the detour route determination device 200 are shown.

[Variation 1 of detour path setting device]
Since the alternative path setting device of variation 1 has the same configuration as that of the alternative path setting device 400 shown in FIG. 4, only the different parts will be described with the same reference numerals. In the alternative path setting device 400 of variation 1, the path setting means 410 receives a bypass path setting request and route information of the bypass path from the bypass route determination device 200, and uses the CLI or the like as an end point of traffic. Static routing (static routing) is set for the IP address and network address, and path setting is performed so as to use an MPLS or GMPLS path. As a result, only a packet in which a destination designated by static routing is set selects a detour. In this case, the detour path setting request unit 270 of the detour path determination apparatus 200 does not need to calculate the detour path metric, so that the processing load is reduced and the detour path setting request is quickly notified to the detour path setting apparatus 400. can do.

[Variation 2 of detour path setting device]
Since the alternative path setting device of variation 2 has the same configuration as that of the alternative path setting device 400 shown in FIG. 4, only the different parts will be described with the same reference numerals. In the alternative path setting device 400 of variation 2, the path setting unit 410 receives a bypass path setting request and route information of the bypass path from the bypass route determination device 200, and uses the CLI or the like to specify the specified ground-to-ground ( The communication packet marking is set between the network nodes), and the path is set so that the traffic to be bypassed uses the designated route. As a result, for example, only a packet in which a destination designated by marking by a network operator is set selects a detour. In this case, the detour path setting request unit 270 of the detour path determination apparatus 200 does not need to calculate the detour path metric, so that the processing load is reduced and the detour path setting request is quickly notified to the detour path setting apparatus 400. can do.

1 is a diagram showing an overall configuration of a communication system in which excessive traffic is saved by a detour route determination method according to an embodiment of the present invention. It is a block diagram which shows typically an example of the detour route determination apparatus which concerns on embodiment of this invention. It is a block diagram which shows typically an example of the network information collection apparatus shown in FIG. It is a block diagram which shows typically an example of the detour path setting apparatus shown in FIG. It is a block diagram which shows typically an example of the traffic alternating current information preparation apparatus shown in FIG. It is a block diagram which shows an example of the detouring link handled with the detour route determination apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows an example of the method of determining the traffic for a detour by the detour route determination apparatus which concerns on embodiment of this invention. It is a sequence diagram which shows evacuation of the excess traffic by the detour route determination method which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Communication system 2 Backbone network 3 (3a-3i) User network 101-108 Network node 111-118 Edge router 200 Detour route determination apparatus 210 Evacuation request reception means 220 Endpoint candidate extraction means 230 Traffic exchange information acquisition means 240 Bypass target traffic amount Determining means 250 Detour endpoint determining means 260 Route calculating means 270 Detour path setting requesting means 280 Traffic exchange information DB
290 Target bandwidth DB
300 Network Information Collection Device 310 Network Information Collection Unit 320 Network Information Notification Unit 330 Topology Information DB
340 Traffic Information DB
400 detour path setting device 410 path setting means 500 traffic exchange information creation device 510 traffic exchange information creation means

Claims (10)

A network information collection device that acquires network traffic information and topology information from each network node constituting the network, and detects one or more continuous links in which link utilization has increased or congestion has occurred as a bypass target link; , A traffic exchange information creation device that creates traffic exchange information related to traffic that uses the detour target link, and a detour route determination device that determines a detour route that bypasses a part of the traffic that uses the detour target link And the detour route determination device of a communication system comprising a detour path setting device that newly sets a path in the detour route,
End point candidate extraction means for extracting network node information as a detour start point candidate and an end point candidate based on the network topology information acquired from the network information collection device and information on the detour target link;
Traffic exchange information acquisition means for acquiring traffic exchange information relating to traffic using the detour target link from the traffic exchange information creation device;
The detour target traffic for determining the detour target traffic amount indicating the traffic amount to be detoured among the traffic using the detour target link based on the traffic exchange information regarding the traffic using the detour target link and the target band. A quantity determining means;
Detour end point determining means for determining a start point and an end point of the detour based on the determined detour target traffic volume and traffic exchange information regarding traffic using the detour target link;
A detour route determination apparatus comprising: a route calculation unit that determines a detour route by calculating a route that connects a start point and an end point of the determined detour route. The route calculation means includes
Topology information for path calculation obtained by acquiring topology information and traffic information of the network from the network information collection device, and removing links in a link usage state that cannot accommodate the amount of traffic to be bypassed from the acquired topology information of the network If the shortest route from the start point to the end point of the detour route is calculated as the detour route using the created topology information for route calculation, and if the shortest route is not obtained, a new 2. The detour route determination device according to claim 1, wherein the detour end point determination unit requests the detour end point determination means to determine a detour start point and an end point.   While receiving a traffic saving request indicating that the detour target link has been detected from the network information collection device, acquiring the topology information and traffic information of the network, and based on the acquired topology information and traffic information of the network The detour route determination apparatus according to claim 1, further comprising save request accepting means for calculating a link usage rate of the entire network as the target bandwidth.   The route information of the bypass route determined by the route calculation means is acquired, the topology information of the network is acquired from the network information collection device, and the metric is smaller than the route of the bypass source from the acquired topology information of the network. For the detour path setting device that calculates the metric of the determined detour path and sets the path of MPLS (Multi-Protocol Label Switching) or GMPLS (Generalized Multi-Protocol Label Switching) as the detour path, The detour path setting request means for notifying a detour path setting request, route information of the detour route, and metric information of the detour route is further provided. The detour route determination device described in 1.   For either the detour path setting device that acquires the route information of the detour route determined by the route calculation means and sets the static routing as the detour path, or the detour path setting device that sets the marking of the packet as the detour path 4. The detour according to claim 1, further comprising detour path setting request means for notifying a detour path setting request and route information of the determined detour path. Routing device. A network information collection device that acquires network traffic information and topology information from each network node constituting the network, and detects one or more continuous links in which link utilization has increased or congestion has occurred as a bypass target link; , A traffic exchange information creation device that creates traffic exchange information related to traffic that uses the detour target link, and a detour route determination device that determines a detour route that bypasses a part of the traffic that uses the detour target link And a detour route determination method by the detour route determination device of a communication system comprising a detour path setting device that newly sets a path in the detour route,
The detour route determination device includes a traffic save request accepting unit, an endpoint candidate extraction unit, a traffic exchange information acquisition unit, a detour target traffic amount determination unit, a detour end point determination unit, a route calculation unit, and a detour path setting request. Means and
Obtaining information on the detour target link from the network information collection device together with the traffic saving request by the traffic saving request receiving means;
Obtaining network topology information from the network information collection device;
An end point candidate extracting step for extracting information on a network node as a start point candidate and an end point candidate of a detour based on the information on the detour target link and the topology information of the network by the end point candidate extracting unit;
A traffic exchange information acquisition step of acquiring traffic exchange information related to traffic using the detour target link from the traffic exchange information creation device by the traffic exchange information acquisition unit;
A detour indicating a traffic amount to be diverted out of traffic using the detour target link based on traffic exchange information and a target band related to traffic using the detour target link by the detour target traffic amount determination unit Detour target traffic volume determination step for determining target traffic volume;
A detour end point determining step for determining a start point and an end point of the detour based on the determined detour target traffic amount and traffic exchange information relating to traffic using the detour target link by the detour end point determining means; ,
A detour route determination comprising: a route calculation step of determining the detour route by calculating a route connecting the start point and the end point of the detour route determined by the route calculation means. Method. The detour route determination device includes:
Before the route calculation step, an information acquisition step of acquiring topology information and traffic information of the network from the network information collection device by the route calculation means;
Further executing a calculation topology information creating step for creating topology information for route calculation by removing a link in a link use state that cannot accommodate the detour target traffic volume from the acquired topology information of the network,
In the route calculation step, using the created topology information for route calculation, the shortest route from the start point to the end point of the detour route is calculated as the detour route,
7. The detour according to claim 6, wherein when the shortest route is not obtained, the detour end point determination means determines a start point and an end point of a new detour in the detour end point determination step. Route determination method. The detour route determination device includes:
And further executing a target bandwidth calculation step of calculating, as the target bandwidth, the link utilization rate of the entire network based on the topology information and traffic information of the network acquired from the network information collection device by the traffic saving request reception means. The detour route determination method according to claim 6 or 7, wherein: The detour route determination device includes:
The detour path setting request means calculates the detour path metric determined in the path calculation step so that the metric is smaller than the detour source path from the network topology information acquired from the network information collection device. A detour path setting request, a detour path setting request, detour path information determined in the route calculation step, and detour path metric information for a detour path setting device that sets an MPLS or GMPLS path as a detour path. The detour path determination method according to any one of claims 6 to 8, further comprising performing a detour path setting requesting step of notifying. The detour route determination device includes:
With respect to either the detour path setting device that sets static routing as a detour path or the detour path setting device that sets packet marking as a detour path by the detour path setting request means, The detour route determination method according to any one of claims 6 to 8, further comprising a detour path setting request step for notifying route information of the detour route determined in the route calculation step.

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