JP2007074074A - Traffic distribution control apparatus, packet communication network, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the number of path management information items possessed by a traffic distribution control apparatus. <P>SOLUTION: The traffic distribution control apparatus particularizes a transfer path set to a packet transfer node in a congestion state, particularizes a sender address and a destination address in pairs in the packet transfer node in the congestion state whereby a traffic flow amount is maximized, and requests an edge node of the particularized sender address to transfer at least part of packets transferred by the particularized transfer path among packets addressed to the edge node of the destination address particularized from the edge node of the particularized sender address by using another transfer path. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention collects and manages traffic information and optimizes the route appropriately when applying traffic engineering technology that assigns a route according to traffic demand and dynamically switches the route according to fluctuations in traffic AC distribution. The present invention relates to a technique for reducing the route information that a distributed control apparatus must have and realizing application of traffic engineering technology to a large-scale network.

  Conventionally, in packet communication networks represented by IP networks, packets are transferred using only the shortest path. For this reason, it is difficult to determine a transfer path in consideration of traffic AC distribution and effective bandwidth. As a result, the load tends to be concentrated on the link or relay router on the shortest path, and there is a possibility that the transfer delay and packet loss due to congestion increase and the communication quality deteriorates.

  As a technique for solving such a problem, there is a traffic engineering technique (see, for example, Non-Patent Document 1 and Non-Patent Document 2). The traffic engineering technique is a technique for distributing traffic on a plurality of relay paths and transferring the traffic according to the traffic AC distribution of the network. When the traffic AC distribution is biased and fluctuates over time, congestion can be avoided by using surplus resources, so that the effective throughput of the entire network can be improved at low cost.

Junichi MURAYAMA et al., “Traffic-Driven Optical IP Networking Architecture”, IEICE TRANS.COMMUN., VOL.E86-B, NO.8, p.2294-2301, 2003 Kenichi Matsui, Toshiyuki Sakurai, Masaki Kaneda, Junichi Murayama, Hiroyuki Ishii, “Examination of Multilayer Traffic Engineering in Terabit-class Super Network”, IEICE Technical Report, NS2002-316, IN2002-289 , P. 297-302, March 2003

  When carrying out the above-described traffic engineering, a traffic distribution control device that distributes traffic by controlling a packet transfer device classifies flows according to traffic trunks in the network. At this time, there is an item of an explicit route as an attribute of the traffic trunk. That is, the traffic distribution control device grasps all routes in the network as explicit routes, determines the traffic trunk to which the traffic to be distributed belongs, and determines which route to which the traffic trunk is remapped. The number of routes increases with the network scale. Specifically, the number of paths corresponding to the number of edge nodes installed at the edge in the network that accommodate subscriber users multiplied by the number of redundant paths between edge nodes must be managed. Don't be. For this reason, there is a problem that the network scale to which the traffic engineering technology can be applied is limited to a medium scale.

  The present invention suppresses the number of route management information that the traffic distributed control device must have when applying the traffic engineering technology from the total number of routes in the network to the number of relay routers in the network, thereby enabling traffic engineering. The purpose is to realize the application of technology to large-scale networks.

The present invention provides a packet communication network that includes a plurality of edge nodes that respectively accommodate user networks and a plurality of packet forwarding nodes that connect the plurality of edge nodes, and forwards packets between the user networks. A traffic distribution control device for controlling the transfer route of the traffic distribution amount collecting storage means for collecting and storing the traffic distribution amount of each pair of the source address and the destination address measured by the packet transfer node; Recognizing the packet forwarding node in which the traffic flow amount exceeds a predetermined value as a congestion state, among the route identifiers of a plurality of forwarding routes set between the plurality of edge nodes, the packet forwarding node in the congestion state First transfer route specifying means for specifying a route identifier of the set transfer route; Edge node address pair specifying means for specifying a pair of a source address and a destination address having the maximum traffic distribution amount in a packet forwarding node in a congested state based on the traffic distribution amount collected by the traffic distribution amount collection storage means; Among the packets addressed to the edge node of the specified destination address from the edge node of the specified source address, at least a part of the packets transferred by the transfer path corresponding to the specified path identifier First setting request means for requesting the edge node of the identified source address to transfer using the transfer path.
Further, one configuration example of the traffic distribution control device of the present invention further includes a route identifier management table for storing a route identifier of the transfer route for each packet forwarding node through which the transfer route passes, The transfer path specifying means acquires the path identifier of the transfer path set in the packet transfer node in the congestion state from the path identifier management table.
Further, one configuration example of the traffic distribution control device of the present invention further includes an analysis unit that analyzes a traffic distribution amount of each transfer route based on the traffic distribution amount collected by the traffic distribution amount storage unit, As a result of analysis by the analysis unit, the first setting request unit distributes traffic on the transfer route of the specified route identifier with respect to a packet addressed to the edge node of the specified destination address from the edge node of the specified source address And when recognizing that there is a difference greater than or equal to a predetermined value between the amount and the traffic distribution amount of the transfer route of the other route identifier corresponding to the same source address and destination address pair as this transfer route, A request is made to the edge node of the specified source address so that this difference is eliminated.
The traffic distribution control apparatus according to the present invention may further include a second transfer that specifies a path identifier corresponding to the packet transfer node that has not responded during the collection by the traffic distribution amount storage unit. All the edge nodes are transferred so that a packet transferred using a transfer path having a path identifier specified by the path specifying means and a path identifier specified by the second transfer path specifying means is transferred using a transfer path having a different path identifier. And second setting requesting means for requesting it.

  In addition, the present invention includes a plurality of edge nodes that respectively accommodate user networks, a plurality of packet forwarding nodes that connect the plurality of edge nodes, and the traffic distribution control device, and packets between the user networks The edge node encapsulates the user packet when the user packet received from the user terminal connected to the user network is a packet addressed to another edge node. First transmission means for transferring, and second transmission means for extracting a user packet from an encapsulated packet received from another edge node and transmitting the user packet to a destination user terminal Is.

Further, the present invention provides a packet communication network having a plurality of edge nodes each accommodating a user network and a plurality of packet forwarding nodes connecting the plurality of edge nodes, and forwarding packets between the user networks. A traffic distribution control apparatus program for operating a computer as a traffic distribution control apparatus for controlling the packet transfer path, wherein the traffic distribution amount for each pair of a source address and a destination address measured by the packet transfer node is Collecting and storing the traffic distribution amount collecting and storing procedure, and recognizing the packet forwarding node in which the traffic circulation amount equal to or more than a predetermined value is generated as a congestion state, and a plurality of forwarding routes set between the plurality of edge nodes. Among the route identifiers, the packet transfer no A first transfer route specifying procedure for specifying the route identifier of the transfer route set in the above, and a pair of a source address and a destination address that maximizes the traffic flow amount at the packet transfer node in the congestion state. Among the packets addressed to the edge node of the specified destination address from the edge node of the specified source address from the edge node of the specified source address specified by the edge node address pair specifying procedure specified based on the traffic distribution amount collected in the collection storage procedure A first setting request for requesting the edge node of the identified source address to transfer at least a part of a packet transferred by a transfer path corresponding to the path identifier using a transfer path of another path identifier The procedure is executed by the computer.
In addition, one configuration example of the traffic distribution control device program of the present invention further includes an analysis procedure for analyzing the traffic distribution amount of each transfer route based on the traffic distribution amount collected in the traffic distribution amount collecting and storing procedure. In the first setting request procedure, as a result of the analysis by the analysis procedure, the transfer route of the specified route identifier is transmitted from the edge node of the specified source address to the edge node of the specified destination address. It is recognized that there is a difference of a predetermined value or more between the traffic distribution amount of the other route identifier and the traffic distribution amount of the transfer route of the other route identifier corresponding to the same source address and destination address pair as the transfer route. In this case, a request is made to the edge node of the specified source address so that this difference is eliminated.
The traffic distribution control apparatus program according to the present invention further includes a second configuration example that specifies a path identifier corresponding to the packet forwarding node that has not responded during the collection by the traffic circulation amount collection and storage procedure. All of the above-mentioned transfer route identification procedure and the packet transferred using the transfer route of the route identifier specified in the second transfer route specification procedure using the transfer route of different route identifiers. A second setting request procedure for requesting the edge node.

  According to the present invention, the transfer path set in the packet forwarding node in the congested state is identified, and the pair of the source address and the destination address that maximizes the traffic distribution amount in the congested packet forwarding node is identified and identified. The specified source so that at least a part of the packets transferred by the specified transfer route among the packets addressed to the edge node of the destination address specified from the edge node of the specified source address are transferred using another transfer route By making a request to the edge node of the address, the edge transfer table that controls the transmission function of the source edge node is rewritten. Thus, in the present invention, when applying the traffic engineering technology that dynamically changes the packet transfer route, the transfer route is identified from the congestion packet transfer node in the network, and the traffic on the congestion route is remapped to another route. be able to. As a result, it is possible to reduce the number of route information that the traffic distributed control apparatus must have when applying the traffic engineering technique. Therefore, it becomes possible to improve the scalability of the traffic engineering technology, to realize the application of the traffic engineering technology to a large-scale network, and to improve the effective throughput of the large-scale network at a low cost.

  Further, in the present invention, by using a path identifier management table that stores the path identifier of the transfer path for each packet transfer node through which the transfer path passes, the transfer path set in the congested packet transfer node is easily specified. be able to.

  In the present invention, the traffic distribution amount of each transfer route is analyzed, and as a result of the analysis, the traffic distribution amount of the specified transfer route corresponds to the same source address and destination address pair as the transfer route. When recognizing that there is a difference of a predetermined value or more between the traffic distribution amount of other transfer routes, by requesting the edge node of the specified source address to eliminate this difference, The traffic distribution amount of each transfer route set for the identified destination address can be made uniform.

  Further, in the present invention, when collecting the traffic distribution amount, the transfer path set in the packet transfer node that did not respond is specified, and the packet transferred using the specified transfer path is transferred to a different transfer path. By requesting all the edge nodes to perform transfer using, it is possible to avoid failures such as link disconnection and packet transfer node failure by switching the transfer path.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an example of a network model of a packet communication network according to an embodiment of the present invention. The packet communication network of FIG. 1 includes edge nodes 1 to 4, packet forwarding nodes 6 to 9, and a traffic distribution control device 5 that controls them. Each terminal device 10-17 is accommodated in edge nodes 1-4 via access networks 18-21. The edge nodes 1 to 4 are connected by packet forwarding nodes 6 to 9. Hereinafter, a backbone network composed of edge nodes 1 to 4 and packet forwarding nodes 6 to 9 is referred to as a core network 22, and a network composed of terminal devices 10 to 17 is referred to as a user network 23.

  FIG. 2 shows an example of a physical model of the packet communication network according to the present embodiment. Each edge node is connected by a plurality of transfer paths. For example, between the edge node 1 and the edge node 3, a transfer path including a link 101, a packet transfer node 6, a link 105, a packet transfer node 7, a link 107, a packet transfer node 9, and a link 103, The packet transfer node 6, the link 106, the packet transfer node 8, the link 108, the packet transfer node 9, and the link 103 are connected by a transfer path. In this way, by connecting the edge nodes with multiple transfer paths, it is possible to avoid congestion and failures due to physical causes such as link disconnection and device congestion by switching the output destination transfer path. Become.

  The traffic distribution control device 5 is connected to the edge nodes 1 to 4 via links 109 to 112, and is connected to the packet forwarding nodes 6 to 9 via links 113 to 116, respectively. In this way, by connecting the traffic distributed control device 5 to each node in the network, centralized management of the network state by the traffic distributed control device 5 can be realized, and as a result, failure detection becomes possible and It is possible to specify all the routes that are affected by.

  FIG. 3 shows an example of a logical model of the packet communication network according to the present embodiment. In the packet communication network of the present embodiment, a route identifier for identifying the route is given to each route. The route identifier takes a different value for each route when attention is paid between certain edge nodes. Since there are a plurality of transfer paths between the edge node and another edge node, the path identifiers overlap.

  Each packet forwarding node handles a route given a specific identifier. In this embodiment, the packet forwarding node 7 handles the route identifier R1, the packet forwarding node 8 handles the route identifier R2, and the packet forwarding nodes 6 and 9 handle both the route identifiers R1 and R2. In FIG. 3, R1 means a route having a route identifier R1, and R2 means a route having a route identifier R2. When attention is paid between the edge node 1 and the edge node 3, there is a route indicated by the route identifier R1 and a route indicated by the route identifier R2. Similarly, when attention is paid between the edge node 2 and the edge node 3, there is a route indicated by the route identifier R1 and a route indicated by the route identifier R2.

  As described above, when attention is paid to a certain edge node, the path identifier takes R1 or R2 which is different for each path, and the path identifier overlaps between the edge node and another edge node. Therefore, the corresponding route identifier can be specified from the packet forwarding node. This is a very important feature of the logical model that is directly related to the reduction of the number of management paths of the traffic distribution control device 5 intended by the present invention.

  FIG. 4 shows a configuration example of the traffic distribution control apparatus 5 of the present embodiment. The traffic distribution control device 5 includes an external device management unit 24 and a load distribution calculation unit 25. The external device management unit 24 includes a traffic information exchange unit 26 and a response management unit 27, and the load distribution calculation unit 25 includes a traffic information holding unit 28 and a route optimization processing unit 29.

  The traffic information sending / receiving unit 26 and the traffic information holding unit 28 constitute a traffic distribution amount collection / storage means for collecting and storing the traffic distribution amount. Then, the route optimization processing unit 29 and the external device management unit 24 include first transfer route specifying means for specifying the transfer route set in the packet transfer node in the congestion state, and traffic distribution in the packet transfer node in the congestion state. Edge node address pair specifying means for specifying a pair of a source address and a destination address with the maximum amount, and traffic distribution amount of each transfer route set for the specified destination address is made uniform. First setting request means for requesting the edge node of the specified source address, analysis means for analyzing the traffic distribution amount of each transfer route, and a packet that did not respond when collecting the traffic distribution quantity Second transfer route specifying means for specifying a transfer route set in the transfer node, and a packet being transferred using this specified transfer route , To transfer using different transfer paths constitute a second setting request means for making a request to all the edge nodes.

  The traffic information transfer unit 26 has a timer A for each node in the network. The traffic information transfer unit 26 sets a function for deriving a corresponding output link and a corresponding timer A from the address of each node, an initial value of the timer A, counts down the timer A, and the timer A becomes zero. A function for resetting the timer A to the initial value at the time, SNMP (Simple Network Management Protocol) and a command line are implemented, and the address of the node for which the corresponding timer A becomes 0 is set as the destination address. When receiving an SNMP reference response in which an SNMP reference request is transmitted to the corresponding output link and the function of referring to the contents of the table and information held by each node and the response to the SNMP reference request are described from each node Then, the traffic information is extracted from the SNMP reference response, and the load balancing calculation unit 25 described later And a function of notifying the traffic information holding unit 28.

  Here, the traffic information is composed of the address of the node that collected the traffic information and the traffic distribution amount collected by the node. Each of the edge nodes 1 to 4 collects the transfer traffic distribution amount for each output link and the traffic distribution amount for each address of the destination edge node. Each of the packet forwarding nodes 6 to 9 collects the forwarding traffic distribution amount for each output link and the traffic distribution amount for each pair of the source edge node address and the destination edge node address.

  The table and information of each node that is assumed to be referred to by the SNMP reference request in this embodiment include an edge transfer table 37, an edge output link specifying table 38, and an edge traffic observation unit 39 held by an edge node described later. Observed traffic volume, the core forwarding table 43 held by the packet forwarding node, the traffic traffic volume observed by the core traffic observation unit 44, and the like.

  The response management unit 27 has a timer B for each node in the network. Then, the response management unit 27 sets a function for deriving the corresponding timer B from the address of each node, sets an initial value of the timer B, and transmits a timer B related to this node when an SNMP reference request is transmitted to the node. The timer B counts down immediately after that, and when the SNMP reference response becomes 0, the timer B is reset to the initial value, and when the timer B becomes 0, the timer B is reset to the initial value. And a function of notifying the load distribution calculating unit 25 that there is no response from the node corresponding to the.

  The external device management unit 24 uses the traffic information exchange unit 26 and the response management unit 27 to collect table information and traffic information of each node and notify the load distribution calculation unit 25, and from the load distribution calculation unit 26 It has a function of transmitting an SNMP setting request to each node based on the notified update route information, rewriting the table information of each node, and remapping traffic to each route.

The traffic information holding unit 28 has a function of managing the traffic distribution amount of each node, each link, and each route by collecting and storing the traffic information received from the traffic information exchanging unit 26.
The route optimization processing unit 29 has a route identifier management table 30. In the route identifier management table 30, the addresses of the packet forwarding nodes 6 to 9 and the route identifiers of forwarding routes passing through the nodes are registered in advance.

  The route optimization processing unit 29 recognizes a congested packet forwarding node by using the traffic distribution amount stored in the traffic information holding unit 28, and manages the route identifier corresponding to the congested packet forwarding node by the route identifier management. A function that is specified by the table 30, calculates path information that the edge node must newly hold in order to reduce traffic transferred by the path corresponding to the path identifier, and notifies the external apparatus management unit 24 of the path information When the response management unit 27 is notified of the packet forwarding node that does not respond to the SNMP reference request, the route identifier corresponding to the packet forwarding node is specified by the route identifier management table 30, and the route corresponding to the route identifier is specified. Forwards traffic forwarded by using a different route Edge node has a function of notifying the external device management unit 24 calculates the path information that must be newly held in order.

  The route optimization processing unit 29 performs calculation for deriving a new route in consideration of the traffic distribution amount of each route when calculating the route information in order to equalize the traffic distribution amount of each route. At this time, the route optimization processing unit 29 performs the traffic distribution amount of the transfer route of the route identifier specified by the route identifier management table 30 and other transfer corresponding to the same source address and destination address pair as this transfer route. When it is recognized that there is a difference of a predetermined value or more with the traffic distribution amount of the route, the route information is calculated so that this difference is eliminated.

  If the goal is simply to remap part of the traffic on the congested route to another route, after identifying the route identifier corresponding to the congested packet forwarding node, And the traffic between the transmission source edge node and the destination edge node that maximizes the traffic distribution amount on the congestion packet forwarding node may be remapped to the new route indicated by the other route identifier.

  The load distribution calculating unit 25 uses the traffic information holding unit 28 and the route optimization processing unit 29 to hold the traffic distribution amount of each node, analyze the traffic distribution amount, and congested links and congestions. A function for identifying a node, a function for calculating a new route to eliminate this congestion, a function for generating updated route information and sending it to the external device management unit 24, and a bypass for a packet forwarding node that does not respond to an SNMP reference request Therefore, it has a function of calculating a new route, generating updated route information, and transmitting it to the external device management unit 24. Here, the update route information is composed of the address of the node to be controlled, which is the destination address of the SNMP setting request, and the request content for requesting to set the calculated new route.

  With the above configuration, when applying the traffic engineering technology, the traffic distribution control device 5 is congested by specifying a route from the identifier (address) of the relay router (packet forwarding nodes 6 to 9) in the network. Remap traffic on a route or a route via a failed node to another route. As a result, the number of route information that the traffic distribution control device 5 must have when applying the traffic engineering technique can be reduced, and thus the scalability of the traffic engineering technique can be improved.

  FIG. 5 shows a configuration example of the edge nodes 1 to 4 of the present embodiment. Each of the edge nodes 1 to 4 includes an edge reception packet processing unit 31, an edge packet processing unit 32, an edge forwarding processing unit 33, an edge header processing unit 34, an edge transmission packet processing unit 35, and an edge server connection. Part 36.

  The edge reception packet processing unit 31, the edge packet processing unit 32, the edge forwarding processing unit 33, the edge header processing unit 34, and the edge transmission packet processing unit 35 are other user packets (IP packets) received from the terminal devices 10-17. The first transmission means for encapsulating and transferring the user packet when the packet is addressed to the edge node of the user, and extracting the user packet from the encapsulated packet received from the other edge node, A second transmission unit configured to transmit the user packet to the destination user terminal.

The edge reception packet processing unit 31 extracts the IP packet by deleting the header for the core network from the core packet received from the core network, and the function of transferring the received IP packet to the edge packet processing unit 32. A function of transferring the packet to the packet processing unit 32.
The edge packet processing unit 32 has a function of extracting a destination IP address from the IP packet extracted by the edge reception packet processing unit 31.

  The edge forwarding processing unit 33 has an edge transfer table 37. In the edge transfer table 37, a destination core address prefix and a route identifier corresponding to the destination IP address are registered in advance. In the core address, information for identifying an edge router is described in the prefix part, and a path identifier for identifying an output destination transfer path at the time of transfer is described in the other part. The edge forwarding processing unit 33 has a function of searching the edge forwarding table 37 using the destination IP address extracted by the edge packet processing unit 32 as a search key and deriving a destination core address prefix and a route identifier corresponding to the destination IP address. ing.

  The edge header processing unit 34 includes the destination core address describing the destination core address prefix and the path identifier specified by the edge forwarding processing unit 33, and the source core address describing the core address prefix assigned to its own edge node. And a function of generating a core header and adding the core header to an IP packet to generate a core packet.

  Note that the fact that the destination core address prefix specified by the edge forwarding processing unit 33 matches the core address prefix assigned to its own edge node means that the packet is addressed to its own edge node. In this case, the edge header processing unit 34 does not generate a core header.

The edge transmission packet processing unit 35 includes an edge output link specifying table 38 and an edge traffic observation unit 39.
In the edge output link specification table 38, the number of the output link corresponding to the destination address is registered in advance.
The edge traffic observation unit 39 has a function of observing the traffic distribution amount for each destination core address of the output packet and the traffic distribution amount for each output link.

  The edge transmission packet processing unit 35 receives a packet from the edge header processing unit 34, refers to the destination address of the packet, specifies the output link by the edge output link specification table 38, and transmits the packet. When the packet is output, the core header area of this packet is searched and the traffic traffic volume is counted for each destination core address using the edge traffic observation unit 39. When the packet is output, the edge traffic observation unit 39 is used. And a function of counting the traffic distribution amount for each output link.

  When the edge transmission packet processing unit 35 searches the edge output link specifying table 38, for a core packet encapsulated in the core header, the destination core address is used as a search key, and the IP that is not encapsulated in the core header. For packets, the destination IP address is used as a search key.

  When the edge server connection unit 36 receives an SNMP reference request from the traffic distribution control device 5, the edge server connection unit 36 generates an SNMP reference response describing the contents of the requested table and traffic distribution amount and transmits it to the traffic distribution control device 5. And when the SNMP setting request is received from the traffic distribution control device 5, the table for which setting is requested and the contents of the traffic distribution amount are changed according to the contents of the SNMP setting request, and an SNMP setting response is generated. And a function of transmitting to the traffic distribution control device 5.

  Examples of the tables and information that are requested to be referenced and set by the SNMP reference request and the SNMP setting request include the traffic distribution volume stored in the edge transfer table 37, the edge output link specifying table 38, and the edge traffic observation unit 39. .

  By installing the edge nodes 1 to 4 in the network as described above, when the traffic distribution control device 5 is installed in the network, the edge nodes 1 to 4 collect traffic information necessary for traffic distribution, It is possible to reflect the route information calculated by the traffic distribution control device 5 on the edge nodes 1 to 4 and distribute the traffic in the network to each route.

  FIG. 6 shows a configuration example of the packet forwarding nodes 6 to 9 of the present embodiment. Each of the packet forwarding nodes 6 to 9 includes a core reception packet processing unit 40, a core transmission packet processing unit 41, and a core server connection unit 42.

The core reception packet processing unit 40 has a function of transferring the received core packet to the core transmission packet processing unit 41.
The core transmission packet processing unit 41 includes a core transfer table 43 and a core traffic observation unit 44. In the core forwarding table 43, output links corresponding to the destination core address prefix and the path identifier are registered in advance. The core traffic observation unit 44 has a function of observing the traffic distribution amount for each pair of the transmission source core address and the destination core address of the output packet and the traffic distribution amount for each output link.

  The core transmission packet processing unit 41 receives the core packet from the core reception packet processing unit 40, refers to the destination core address of the core packet, specifies the output link by the core forwarding table 43, and transmits the core packet When outputting a core packet, the core header area of this packet is searched and the traffic distribution amount is counted for each pair of the source core address and the destination core address, and the output link is output when the core packet is output. It has a function of counting the traffic distribution volume every time.

  When the core server connection unit 42 receives the SNMP reference request from the traffic distribution control device 5, the core server connection unit 42 generates an SNMP reference response describing the requested table and the content of the traffic distribution amount and transmits the SNMP reference response to the traffic distribution control device 5. And when the SNMP setting request is received from the traffic distribution control device 5, the table for which setting is requested and the contents of the traffic distribution amount are changed according to the contents of the SNMP setting request, and an SNMP setting response is generated. And a function of transmitting to the traffic distribution control device 5. Examples of the tables and information that are requested to be referred and set by the SNMP reference request and the SNMP setting request include the traffic volume stored in the core transfer table 43 and the core traffic observation unit 44.

  By installing the packet forwarding nodes 6 to 9 in the network as described above, when the traffic distribution control device 5 is installed in the network, the packet forwarding nodes 6 to 9 collect the traffic information necessary for traffic distribution. It becomes possible. Further, when the packet forwarding nodes 6 to 9 fail, it is not possible to respond to the SNMP reference request, so that the traffic distribution control device 5 detects the failure of the node and distributes the traffic to other routes that do not pass through the node. It becomes possible.

Next, operation examples of the traffic distribution control device 5 and the packet communication network according to this embodiment will be described using the physical model of the packet communication network of FIG.
In this operation example, an address of user # 1 is assigned to the terminal device 10, an address of user # 2 is assigned to the terminal device 11, an address of user # 3 is assigned to the terminal device 12, and a user # 3 is assigned to the terminal device 13. 4 is assigned, the terminal device 14 is assigned an address of user # 5, the terminal device 15 is assigned an address of user # 6, the terminal device 16 is assigned an address of user # 7, and the terminal device 17 is assigned an address. Assume that an address of user # 8 is assigned.

  Further, the core node prefix # 1 is assigned to the edge node 1, the core address prefix # 2 is assigned to the edge node 2, the core address prefix # 3 is assigned to the edge node 3, and the core address prefix # 4 is assigned to the edge node 4. Is assigned, the core address # 5 is assigned to the traffic distribution control device 5, the core address # 6 is assigned to the packet forwarding node 6, the core address # 7 is assigned to the packet forwarding node 7, and the core is assigned to the packet forwarding node 8. Assume that address # 8 is assigned and core address # 9 is assigned to packet forwarding node 9.

  FIG. 8 shows a logical model of the packet communication network of this operation example. The packet transfer node 6 holds a route corresponding to the route identifier R1 and a route corresponding to the route identifier R2 as transfer routes, and the packet transfer node 7 holds a route corresponding to the route identifier R1 as transfer routes. The node 8 has a route corresponding to the route identifier R2 as a transfer route, and the packet transfer node 9 has a route corresponding to the route identifier R1 and a route corresponding to the route identifier R2 as a transfer route.

  FIG. 9 shows a packet transfer situation before the path switching in this operation example. First, an IP packet transferred from the terminal device 10 having the user address # 1 to the terminal device 14 having the user address # 5 will be described. The edge node 1 that has received the IP packet from the terminal device 10 adds a core header including the destination core address consisting of the destination core address prefix # 3 and the path identifier R1 and the source core address # 1 to the IP packet. And the core packet is transferred to the packet transfer node 6 from the output link corresponding to the destination core address.

  The packet forwarding node 6 that has received the core packet refers to the destination core address of the core packet, and forwards the core packet from the output link corresponding to this destination core address to the packet forwarding node 7. By the same operation, the packet transfer node 7 transfers the received core packet to the packet transfer node 9, and the packet transfer node 9 transfers the received core packet to the edge node 3.

  The edge node 3 extracts the IP packet by removing the core header from the received core packet, refers to the destination IP address of the IP packet, and transfers the IP packet from the output link corresponding to the destination IP address to the terminal device 14 To do.

  Next, an IP packet transferred from the terminal device 11 having the user address # 2 to the terminal device 15 having the user address # 6 will be described. The edge node 1 that has received the IP packet from the terminal device 11 adds a core header including the destination core address consisting of the destination core address prefix # 3 and the path identifier R1 and the source core address # 1 to the IP packet. And the core packet is transferred to the packet transfer node 6 from the output link corresponding to the destination core address.

  The packet transfer node 6 that has received the core packet transfers the core packet from the output link corresponding to the destination core address of the core packet to the packet transfer node 7. By the same operation, the packet transfer node 7 transfers the received core packet to the packet transfer node 9, and the packet transfer node 9 transfers the received core packet to the edge node 3.

The edge node 3 extracts an IP packet from the received core packet, refers to the destination IP address of the IP packet, and transfers the IP packet from the output link corresponding to the destination IP address to the terminal device 15.
In the packet transfer situation as described above, it is assumed that traffic is concentrated on the packet transfer node 7 and congestion occurs.

  10 shows an edge transfer table 37 of the edge node 1 in the packet transfer situation shown in FIG. 9, FIG. 11 shows an edge output link identification table 38 of the edge node 1 in the packet transfer situation, and FIG. The traffic information collected by the edge traffic observation unit 39 of the edge node 1 in the packet transfer situation is shown.

  When the edge reception packet processing unit 31 of the edge node 1 receives the IP packet from the terminal device 10, the edge packet processing unit 32 extracts the destination IP address # 5 from the IP packet. The edge forwarding processing unit 33 searches the edge forwarding table 37 shown in FIG. 10 using the destination IP address # 5 as a search key, and the destination core address prefix is # 3 for the IP packet of the destination IP address # 5. , It recognizes that the route identifier is R1. Thereby, the edge header processing unit 34 adds a core header including the destination core address consisting of the destination core address prefix # 3 and the route identifier R1 and the source core address # 1 to the IP packet of the destination IP address # 5. Give.

  Next, the edge transmission packet processing unit 35 of the edge node 1 searches the edge output link identification table 38 shown in FIG. 11 using the destination core address of the core packet generated by the edge header processing unit 34 as a search key, For the core packet with the destination core address prefix # 3, the output link is recognized as 101, and the core packet is transferred from the output link 101 to the packet forwarding node 6.

  On the other hand, the edge traffic observation unit 39 of the edge node 1 collects 246 as the traffic distribution amount for the output core packet of the destination core address prefix # 3 and the route identifier R1, as shown in the traffic information T1 of FIG. At the same time, as shown in the traffic information T2 of FIG. 12 (B), 7156 is collected as the traffic distribution amount for the output link 101. The above is the operation of the edge node 1 in the packet transfer situation shown in FIG.

FIG. 13 shows the core forwarding table 43 of the packet forwarding node 6 in the packet forwarding situation shown in FIG. 9, and FIG. 14 shows the traffic information collected by the core traffic observation unit 44 of the packet forwarding node 6 in the packet forwarding situation. Show.
When the core reception packet processing unit 40 of the packet forwarding node 6 receives a core packet from the edge node 1, the core transmission packet processing unit 41 uses the destination core address of this core packet as a search key, and the core forwarding table shown in FIG. 43, the core packet of the destination core address prefix # 3 and the route identifier R1 is recognized as the output link 105, and the core packet is transferred from the output link 105 to the packet forwarding node 7.

  The core traffic observation unit 44 of the packet forwarding node 6 distributes traffic regarding the output core packet of the source core address # 1, the destination core address prefix # 3, and the route identifier R1, as indicated by the traffic information T3 in FIG. In addition to collecting 246 as the amount, 10021 is collected as the traffic distribution amount with respect to the output link 105 as shown in the traffic information T4 in FIG. The above is the operation of the packet forwarding node 6 in the packet forwarding situation shown in FIG.

  FIG. 15 shows a route identifier management table 30 of the traffic distribution control device 5. The traffic information exchange unit 26 of the traffic distribution control device 5 transmits an SNMP reference request to each node in the network, extracts the traffic information from the SNMP reference response returned from each node, and sends it to the traffic information holding unit 28. Notice. The traffic information holding unit 28 stores the traffic information received from the traffic information exchanging unit 26.

  The route optimization processing unit 29 of the traffic distribution control device 5 determines the state of each of the packet forwarding nodes 6 to 9 based on the traffic distribution amount stored in the traffic information holding unit 28, and the packet forwarding node 7 is congested. Recognize that it has occurred. At this time, whether or not each of the packet forwarding nodes 6 to 9 is congested is determined based on a predetermined value that is determined in advance. What is necessary is just to determine that it is a congestion state. Then, the route optimization processing unit 29 searches the route identifier management table 30 shown in FIG. 15 using the address # 7 of the packet forwarding node 7 in the congested state as a search key, and the route identifier corresponding to the packet forwarding node 7 is found. Recognized as R1.

  Further, the route optimization processing unit 29 acquires the address of the edge node pair having the maximum traffic distribution amount in the packet forwarding node 7 based on the traffic distribution amount stored in the traffic information holding unit 28. Here, the address of the source edge node is # 1, and the address of the destination edge node is # 3. Then, the route optimization processing unit 29 sets a new route, specifically, so that the number of packets transferred by the route corresponding to the route identifier R1 among the packets addressed from the source edge node 1 to the destination edge node 3 is reduced. Calculates a route corresponding to the route identifier R2 and notifies the external device management unit 24 of updated route information.

  The external device management unit 24, based on the updated route information notified from the route optimization processing unit 29, has an entry whose destination core address prefix is # 3 and whose route identifier is R1 in the edge forwarding table 37 of the edge node 1. An SNMP setting request for requesting to rewrite the path identifier to R2 is transmitted to the edge node 1 for a part of the node ID.

  At this time, the route optimization processing unit 29 specifically calculates what percentage of the corresponding entry of the edge transfer table 37 is to be rewritten depending on the calculation algorithm possessed, and gives an instruction through the external device management unit 24. Is possible. Further, when the traffic distribution control device 5 manages the route identifier for the user address, the route optimization processing unit 29 specifically calculates which destination user address of the corresponding entry in the edge transfer table 37 is to be rewritten. It is possible to instruct.

  FIG. 16 shows a packet transfer situation after the path switching. The edge server connection unit 36 of the edge node 1 rewrites the contents of the edge forwarding table 37 in response to the SNMP setting request transmitted from the traffic distribution control device 5. Here, it is assumed that in the edge forwarding table 37, among the entries whose destination core address prefix is # 3 and whose path identifier is R1, the path identifier is rewritten to R2 for the entry whose destination IP address is # 6.

  As a result, the packet forwarding node 6 forwards the packet addressed to the IP address # 6 to the packet forwarding node 8 after the packet whose destination core address prefix is # 3, so that the traffic is distributed to the two routes. In this way, the concentration of traffic on the packet forwarding node 7 can be eliminated.

17 shows the edge transfer table 37 of the edge node 1 in the packet transfer situation shown in FIG. 16, and FIG. 18 shows the traffic information collected by the edge traffic observation unit 39 of the edge node 1 in the packet transfer situation.
By rewriting the edge transfer table 37 by the edge server connection unit 36 described above, the route identifier corresponding to the destination IP address # 6 is changed to R2 in FIG.

  When the edge reception packet processing unit 31 of the edge node 1 receives the IP packet from the terminal device 10, the edge packet processing unit 32 extracts the destination IP address # 6 from this IP packet. The edge forwarding processing unit 33 searches the edge forwarding table 37 shown in FIG. 17 using the destination IP address # 6 as a search key, and the destination core address prefix is # 3 for the IP packet of the destination IP address # 6. , The route identifier is recognized as R2. Thereby, the edge header processing unit 34 adds a core header including the destination core address composed of the destination core address prefix # 3 and the route identifier R2 and the source core address # 1 to the IP packet of the destination IP address # 6. Give.

  Also in the packet transfer situation shown in FIG. 16, the edge output link specifying table 38 of the edge node 1 is as shown in FIG. 11, and the edge transmission packet processing unit 35 outputs the core packet of the destination core address prefix # 3. Transfer from the link 101 to the packet forwarding node 6.

  As shown in the traffic information T1 of FIG. 18A, the edge traffic observation unit 39 of the edge node 1 collects the traffic distribution amount regarding the output core packets of the destination core address prefix # 3 and the path identifiers R1 and R2, and As shown in the traffic information T2 in FIG. 18B, the traffic circulation volume is collected for the output link 101.

  Even after the edge transfer table 37 is rewritten, the output link of the core packet of the destination core address prefix # 3 remains 101, so that the traffic information T2 has not changed from the state of FIG. On the other hand, since the packet addressed to the IP address # 6 is transferred by the route corresponding to the route identifier R2, the traffic distribution amount for the traffic information T1 is 21 for the output core packet of the destination core address prefix # 3 and the route identifier R2. It can be seen that it has increased. The above is the operation of the edge node 1 in the packet transfer situation shown in FIG.

FIG. 19 shows the traffic information collected by the core traffic observation unit 44 of the packet forwarding node 6 in the packet forwarding situation shown in FIG.
Also in the packet transfer situation shown in FIG. 16, the core transfer table 43 of the packet transfer node 6 is as shown in FIG. Therefore, when the core reception packet processing unit 40 of the packet forwarding node 6 receives the core packet from the edge node 1, the core transmission packet processing unit 41 searches the core forwarding table 43 using the destination core address of the core packet as a search key. Then, the core packet of the destination core address prefix # 3 and the route identifier R2 is recognized as the output link 106, and the core packet is transferred from the output link 106 to the packet forwarding node 8.

  As shown in the traffic information T3 in FIG. 19A, the core traffic observation unit 44 of the packet forwarding node 6 relates to the output core packets of the source core address # 1, the destination core address prefix # 3, and the path identifiers R1 and R2. The traffic distribution amount is collected, and the traffic distribution amount is collected with respect to the output links 105 and 106 as shown in the traffic information T4 in FIG.

  Since the packet addressed to the IP address # 6 is transferred by the route corresponding to the route identifier R2, the traffic information T3 is related to the output core packet of the source core address # 1, the destination core address prefix # 3, and the route identifier R2. It can be seen that the traffic distribution amount has increased to 113, and for the traffic information T4, the traffic distribution amount for the output link 106 has increased to 5727. The above is the operation of the packet forwarding node 6 in the packet forwarding situation shown in FIG.

  As described above, in the present embodiment, when applying the traffic engineering technology, the traffic distribution control device 5 identifies a transfer route that is congested from a relay router (packet transfer node) in the network, and this congestion route Remap the above traffic to another route. Thereby, in this embodiment, when applying the traffic engineering technology, the number of route information that the traffic distribution control device 5 must have can be suppressed from the total number of routes in the network to the number of relay routers, The scalability of traffic engineering technology can be improved.

  The traffic distribution control device 5, the edge nodes 1 to 4, and the packet forwarding nodes 6 to 9 according to the present embodiment control a computer having a CPU, a storage device, and an interface, and hardware resources thereof. It can be realized by a program to do. A program for causing a computer to function as each device is provided in a state of being recorded on a recording medium such as a flexible disk, a CD-ROM, a DVD-ROM, or a memory card. The CPU writes the read program into the storage device, and executes the processing described in this embodiment in accordance with the program stored in the storage device.

  The present invention can be applied to a packet communication network.

It is a block diagram which shows an example of the network model of the packet communication network which concerns on embodiment of this invention. It is a figure which shows an example of the physical model of the packet communication network which concerns on embodiment of this invention. It is a figure which shows an example of the logical model of the packet communication network which concerns on embodiment of this invention. It is a block diagram which shows the structural example of the traffic distribution control apparatus in embodiment of this invention. It is a block diagram which shows the structural example of the edge node in embodiment of this invention. It is a block diagram which shows the structural example of the packet forwarding node in embodiment of this invention. It is a figure which shows the physical model of the operation example of the packet communication network of embodiment of this invention. It is a figure which shows the logical model of the operation example of the packet communication network of embodiment of this invention. It is a figure which shows the packet transfer condition before the path | route switch in the packet communication network of embodiment of this invention. It is a figure which shows the edge transfer table of the edge node in the packet transfer condition of FIG. It is a figure which shows the edge output link specific table of the edge node in the packet transfer condition of FIG. FIG. 10 is a diagram illustrating traffic information collected by an edge traffic observation unit of an edge node in the packet transfer situation of FIG. 9. It is a figure which shows the core transfer table of the packet transfer node in the packet transfer condition of FIG. FIG. 10 is a diagram illustrating traffic information collected by the core traffic observation unit of the packet forwarding node in the packet forwarding state of FIG. 9. It is a figure which shows the path | route identifier management table of the traffic distribution control apparatus in embodiment of this invention. It is a figure which shows the packet transfer condition after the path | route switch in the packet communication network of embodiment of this invention. It is a figure which shows the edge transfer table of the edge node in the packet transfer condition of FIG. It is a figure which shows the traffic information which the edge traffic observation part of the edge node collected in the packet transfer condition of FIG. It is a figure which shows the traffic information which the core traffic observation part of the packet transfer node collected in the packet transfer condition of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1-4 ... Edge node, 5 ... Traffic distributed control apparatus, 6-9 ... Packet forwarding node, 10-17 ... Terminal device, 18-21 ... Access network, 22 ... Core network, 23 ... User network, 24 ... External device Management unit 25 ... Load distribution calculation unit 26 ... Traffic information exchange unit 27 ... Response management unit 28 ... Traffic information holding unit 29 ... Route optimization processing unit 30 ... Route identifier management table 31 ... Edge received packet Processing unit 32... Edge packet processing unit 33. Edge forwarding processing unit 34. Edge header processing unit 35 35 Edge transmission packet processing unit 36 Edge server connection unit 37 Edge transfer table 38 Edge output Link specification table, 39... Edge traffic observation unit, 40... Core reception packet processing unit, 41. Tsu door processing unit, 42 ... core server connections, 43 ... core transfer table, 44 ... core traffic observation unit, 101 to 116 ... link.

Claims (8)

In a packet communication network having a plurality of edge nodes each accommodating a user network and a plurality of packet forwarding nodes connecting the plurality of edge nodes, and forwarding packets between the user networks, the packet forwarding path is A traffic distributed control device for controlling,
Traffic distribution amount storage means for collecting and storing the traffic distribution amount for each pair of the source address and the destination address measured by the packet forwarding node;
Recognizing the packet forwarding node in which the traffic flow amount exceeds a predetermined value as a congestion state, among the route identifiers of a plurality of forwarding routes set between the plurality of edge nodes, the packet forwarding node in the congestion state First transfer route specifying means for specifying a route identifier of the set transfer route;
Edge node address pair specifying means for specifying a pair of a source address and a destination address having the maximum traffic distribution amount in the congestion state packet forwarding node based on the traffic distribution amount collected by the traffic distribution amount storage means; ,
Transfer of at least a part of a packet transferred from the edge node of the specified source address to the edge node of the specified destination address by a transfer path corresponding to the specified path identifier is transferred to another path identifier. A traffic distribution control apparatus comprising: a first setting requesting unit that requests an edge node of the identified source address to transfer data using a route. The traffic distribution control device according to claim 1,
And a path identifier management table for storing a path identifier of the transfer path for each of the packet transfer nodes through which the transfer path passes,
The traffic distribution control device, wherein the first transfer route specifying means acquires a route identifier of a transfer route set in the congestion state packet transfer node from the route identifier management table. The traffic distribution control device according to claim 1 or 2,
Furthermore, it has an analysis means for analyzing the traffic distribution volume of each transfer route based on the traffic distribution volume collected by the traffic distribution volume storage means.
As a result of analysis by the analysis unit, the first setting request unit is configured to transfer traffic on the transfer path of the specified path identifier with respect to a packet addressed to the edge node of the specified destination address from the edge node of the specified source address. When recognizing that there is a difference of a predetermined value or more between the distribution amount and the traffic distribution amount of the transfer route of the other route identifier corresponding to the same source address and destination address pair as this transfer route The traffic distribution control apparatus requests the edge node of the specified source address so that the difference is eliminated. In the traffic distribution control device according to claim 3,
A second forwarding route specifying means for specifying a route identifier corresponding to the packet forwarding node that did not respond at the time of collection by the traffic volume collection storage means;
Requests are made to all the edge nodes to transfer a packet transferred using the transfer path of the path identifier specified by the second transfer path specifying means using a transfer path of a different path identifier. A traffic distribution control apparatus comprising: 2 setting request means; A plurality of edge nodes that respectively accommodate user networks, a plurality of packet forwarding nodes that connect between the plurality of edge nodes, and the traffic distribution control device according to any one of claims 1 to 4, A packet communication network for transferring packets between the user networks,
The edge node is
First transmission means for encapsulating and transferring a user packet received from a user terminal connected to the user network when the user packet is a packet addressed to another edge node;
A packet communication network comprising: second transmission means for extracting a user packet from an encapsulated packet received from another edge node and transmitting the user packet to a destination user terminal. In a packet communication network having a plurality of edge nodes each accommodating a user network and a plurality of packet forwarding nodes connecting the plurality of edge nodes, and forwarding packets between the user networks, the packet forwarding path is A traffic distribution control program for operating a computer as a traffic distribution control device to be controlled,
A traffic distribution amount collection storage procedure for collecting and storing the traffic distribution amount for each pair of a source address and a destination address measured by the packet forwarding node;
Recognizing the packet forwarding node in which the traffic flow amount exceeds a predetermined value as a congestion state, among the route identifiers of a plurality of forwarding routes set between the plurality of edge nodes, the packet forwarding node in the congestion state A first transfer route specifying procedure for specifying a route identifier of the set transfer route;
Edge node address pair identification procedure for identifying a pair of a source address and a destination address having the maximum traffic distribution amount in the congestion state packet forwarding node based on the traffic distribution amount collected in the traffic distribution amount collection storage procedure When,
Transfer of at least a part of a packet transferred from the edge node of the specified source address to the edge node of the specified destination address by a transfer path corresponding to the specified path identifier is transferred to another path identifier. A program for a traffic distribution control apparatus, which causes the computer to execute a first setting request procedure for requesting an edge node of the identified source address to transfer using a route. The traffic distributed control device program according to claim 6,
And an analysis procedure for analyzing the traffic volume of each transfer route based on the traffic volume collected in the traffic volume collection and storage procedure,
In the first setting request procedure, as a result of the analysis by the analysis procedure, the traffic of the transfer route of the specified route identifier is related to the packet addressed to the edge node of the specified destination address from the edge node of the specified source address. When recognizing that there is a difference of a predetermined value or more between the distribution amount and the traffic distribution amount of the transfer route of the other route identifier corresponding to the same source address and destination address pair as this transfer route The traffic distribution control program for requesting the edge node of the specified source address to eliminate this difference. The traffic distributed control device program according to claim 7,
Furthermore, a second transfer route specifying procedure for specifying a route identifier corresponding to the packet transfer node that did not respond at the time of collection by the traffic circulation amount collection and storage procedure;
Requests all the edge nodes to transfer the packet transferred using the transfer path having the path identifier specified in the second transfer path specifying procedure using the transfer path having a different path identifier. A traffic distributed control apparatus program comprising: a second setting request procedure.

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