JP2010130465A - Device, system and method for calculating communication traffic matrix, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve estimation accuracy and reduce a calculation time when calculating an estimation value of a communication traffic matrix volume among respective nodes in a network. <P>SOLUTION: A communication traffic matrix calculation device calculates an initial value tg<SB>m</SB>of estimation values of a communication traffic matrix volume of each flow in a network by the Gravity method. In this case, for the estimation values of which the initial value tg<SB>m</SB>exceeds an IF unit traffic matrix volume x<SB>i</SB>, each tgm value is corrected to a value obtained by dividing the IF unit traffic matrix volume x<SB>i</SB>by the number of flows of its link. For the estimation values of which the initial value tg<SB>m</SB>is not smaller than a predetermined threshold value T<SB>low</SB>, each estimation value is calculated by applying the TomoGravity method. For the estimation values of which the initial value tg<SB>m</SB>is smaller than the predetermined threshold value T<SB>low</SB>, each estimation value is used as it is without applying the TomoGravity method. A value obtained by integrating those values is output as an estimation value of the communication traffic matrix volume. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for calculating the amount of AC traffic in a communication network such as IP (Internet Protocol) or MPLS (Multi-Protocol Label Switching).

  In a network, it is important to optimize the network topology and route so as to effectively utilize the resources of the entire network, maintain the transfer quality, and reduce the network cost. In order to optimize the topology and route of such a network, in addition to information on the network topology and route, information on the amount of AC traffic that is the amount of traffic between any two nodes is required. Conventionally, by implementing xFlow such as NetFlow (registered trademark) or sFLOW (registered trademark) on the nodes in the network, the amount of traffic in units of flows (flows starting from any two nodes in the network) Can be measured. However, if it is attempted to measure the traffic amount in units of flows between all nodes in the network, it takes a long time and is not practical (see Non-Patent Document 1).

As a method of solving such a problem, based on the input / output traffic volume of each node with a relatively low information collection load from the network, an AC traffic volume (between each node) using a gravity model etc. There has been proposed an AC traffic estimation method for estimating a round-trip traffic amount (see Non-Patent Document 2).
N.Benameur and JWRoberts, "Traffic Matrix Inference in IP Networks," Networks and Spatial Economics Volume 4, Number 1, p103-114, March 2004 Y. Ohsita, et al., "Estimation of current traffic matrices from long-term traffic variations," Broadnets 2008, September 2008

  However, when a model (for example, a gravity model) used in this AC traffic estimation method is different from the actual traffic tendency in the network, there is a problem that an estimation error of the AC traffic amount becomes large. This problem will be described with reference to FIG.

  FIG. 9 is a diagram illustrating an AC traffic estimation method as a comparative example. In the AC traffic estimation method (Gravity method) using this gravity model, the AC traffic between two nodes is determined from information on the input / output traffic volume (at least one of the input traffic volume and the output traffic volume) of each node constituting the network. Calculate the quantity. For example, consider a case where an estimated value of the amount of AC traffic between nodes A and D is calculated. In such a case, as shown in FIG. 9, when the input / output traffic volume of the node A and the node D is large, the estimated value of the AC traffic volume between the nodes A and D calculated by the Gravity method also becomes a large value. Become. However, since the link utilization rate between the nodes A and D is actually “0”, the AC traffic amount between the nodes A and D is “0”. In other words, if the AC traffic volume is estimated using only the input / output traffic volume of each interface, the value may be calculated as an excessive value. Here, it is possible to improve the estimation accuracy by calculating the estimated value of the AC traffic amount from various viewpoints, but the calculation amount for that is enormous.

  Therefore, the present invention aims to solve the above-mentioned problems and improve the estimation accuracy and reduce the calculation time when calculating the estimated value of the amount of AC traffic between each node in the network. To do.

In order to solve the above-mentioned problem, the invention according to claim 1 is an AC traffic calculation device for calculating an estimated value of a traffic volume between two arbitrary nodes of a network, and each node constituting the network For each interface identification information, the interface unit traffic information indicating the traffic volume of the input traffic or the output traffic to the interface, the identification information of the start node and the end node of the flow for each flow flowing through the network, Referring to the path information, a storage unit that stores path information indicating the identification information of the interface that passes between the start node and the end node in the flow, an input unit that receives input of interface unit traffic information and path information, and Configure the network An arbitrary two node pair is selected from the node group, and the traffic amount related to the interface of the node pair is read from the interface unit traffic information for each of the selected node pair, and the Gravity method is used using the read traffic amount Thus, an initial value calculation unit that calculates an initial value tg that is a set of initial values tg _m of estimated values of traffic in each network in this network, and a link that connects nodes in the network with reference to route information For each, a flow accommodated in the link is specified, and an initial value tg _m of an estimated value of the traffic amount of the specified flow is an interface unit traffic amount x _{i of the} link indicated in the interface unit traffic information. To determine whether the link When more than Esu unit traffic volume x _i, and the initial value correction unit that performs the initial value correction process for correcting the value indicating the value of the initial value tg _m, the following equation (1),
(Interface unit traffic amount x _{i of the} link) ÷ (Number of flows F _i accommodated in the link) Equation (1)
(1) from the route information, the value of the initial value tg _m and the route information _{A c} extracted path information more flows predetermined threshold _{T low,} (2) of the initial value tg _m, the threshold value is predetermined From the set T _c (G) of the initial value tg _m equal to or greater than T _low and (3) the contribution of the set T _fix ^est of the initial value tg _m whose value is less than a predetermined threshold T _low from the interface unit traffic information Among the initial value tg _m , a traffic amount estimation unit that calculates an estimated value T _c ^est of a traffic amount of a flow equal to or greater than a predetermined threshold T _low by the TomoGravity method using the removed interface unit traffic information X _c , a set T _fix ^est of the initial value tg _m whose value is less than the predetermined threshold value T _low, the calculated value obtained by integrating the estimated value T _c ^est, any two nodes in the network AC traffic calculation apparatus characterized by comprising an alternating current traffic output unit for outputting as an estimate of the traffic volume of definitive flow.

According to the sixth aspect of the present invention, there is provided an AC traffic calculation device for calculating an estimated value of a traffic amount of a flow between any two nodes of a network, for each interface identification information of each node constituting the network. For each flow that flows through the network, for each flow that flows through the network, for each flow that flows through the network, between the start node and the end node in the flow A step of receiving an input of route information indicating identification information of an interface to be selected, a pair of arbitrary two nodes is selected from a group of nodes constituting the network with reference to the route information, and the selected pair of nodes For each Esu unit reads the traffic related interface traffic information from the node pair, by Gravity method using a traffic amount thus read out, the initial value is a set of initial values tg _m of the estimated value of the traffic volume of each flow in the network For each link connecting nodes in the network with reference to the step of calculating tg and the path information, the flow accommodated in the link is identified, and the initial estimated value of the traffic amount of the identified flow when the value of the value tg _m, it is determined whether the exceeding interface unit traffic volume x _i of the link shown in the interface unit traffic information, more than an interface unit traffic volume x _i of the link, the initial value tg _m The initial value that corrects the value to the value shown in the following equation (1) Performing value correction processing;
Interface unit traffic amount x _i ) of the link ÷ (number of flows F _i accommodated in the link) (1)
(1) from the route information, the value of the initial value tg _m and the route information _{A c} extracted path information more flows predetermined threshold _{T low,} (2) of the initial value tg _m, the threshold value is predetermined From the set T _c (G) of the initial value tg _m equal to or greater than T _low and (3) the contribution of the set T _fix ^est of the initial value tg _m whose value is less than a predetermined threshold T _low from the interface unit traffic information A step of calculating an estimated value T _c ^est of a traffic amount of a flow equal to or greater than a predetermined threshold value T _low by the TomoGravity method using the removed interface unit traffic information X _c, and the value of the initial value tg _m is given a set T _fix ^est threshold T _low than become initial values tg _m, the calculated value obtained by integrating the estimated value T _c ^est, off at any two nodes in the network And an AC traffic calculation method and a step of outputting as an estimate of the amount of traffic over.

By doing so, the AC traffic calculation device calculates the initial value tg of the estimated value of the AC traffic volume between the nodes in the network by the Gravity method. Then, the AC traffic calculation device corrects the initial value tg as follows. That is, first, for each link in the network, the AC traffic calculation device calculates the IF (interface) unit traffic amount xi in the link for the initial value tg _m of the estimated value of the AC traffic amount related to the flow m in the link. If exceeded, the initial value tg _m is corrected to (IF unit traffic amount x _{i of} link i) ÷ (number of flows accommodated in link i). In other words, it is excessive values for apparent initial value tg _m, corrected to the average value per flow. Then, after the AC traffic calculation apparatus corrects such an initial value tg, the AC traffic calculation apparatus selects an initial value tg _{m to} be corrected by the TomoGravity method. That is, of the initial value tg _m, the value _below the threshold value T _low (this threshold value T _low is a value not less than 0 and not more than the IF unit traffic amount x _{i and} preferably close to 0) is an excessive value. It is very unlikely. Therefore, it is not a target for correction by the TomoGravity method. On the other hand, of the initial value tg _m , a value equal to or higher than the threshold value T _low may be an excessive value. Therefore, it is set as a correction target by the TomoGravity method. By doing so, the AC traffic calculation apparatus corrects the initial value tg _{m for} which it is clear that the initial value tg _m is excessive, so that the estimation accuracy of the AC traffic amount between each node in the network And the calculation time can be reduced.

According to the second aspect of the present invention, in the AC traffic calculation apparatus according to the first aspect, the initial value correcting unit determines that the traffic amount in the link is a predetermined threshold value U from the link connecting the nodes in the network. It is characterized in that a link that is less than _low is extracted, and initial value correction processing is performed on the extracted link.

By doing in this way, the AC traffic calculation device corrects the initial value tg _m for the link that connects the nodes in the network and for which the traffic amount of the link is less than the predetermined threshold value U _low. I do. Therefore, it is possible to perform an initial value tg _m correct narrow are likely to be the initial value tg _m becomes excessively large value link. That is, the AC traffic amount calculating device can be efficiently corrected initial value tg _m.

The invention according to claim 3 is a route reachability confirmation unit for determining whether or not each flow has reachability by referring to the route information in the AC traffic calculation device according to claim 1 or claim 2. A second initial value correction unit that corrects the value of tg _m related to the flow determined not to have the route reachability by the route reachability confirmation unit out of tg _m calculated by the initial value correction unit; It is further provided with the feature.

According to a fourth aspect of the present invention, the AC traffic calculation device according to the first or second aspect further includes a route reachability confirmation unit that refers to the route information and determines whether or not each flow has route reachability. In place of the initial value correction unit, the flow information is identified for each link connecting the nodes in the network, and the traffic amount of the identified flow is estimated. A second initial value correction unit that corrects the value of tg _m related to the flow determined to have no route reachability by the route reachability confirmation unit among the initial value tg _m of the value to 0 And

In this way, the AC traffic computing device, for obvious flow that there is no reachability, the value of the initial value tg _m may be "0". Therefore, the AC traffic calculation device can further improve the estimation accuracy of the AC traffic amount between the nodes in the network.

  According to a fifth aspect of the present invention, the AC traffic calculation apparatus according to any one of the first to fourth aspects, the route information in the communication network and the interface unit traffic information are collected, and the collected route information is collected. And an AC traffic calculation system including a node that transmits interface unit traffic information in response to a request from the AC traffic calculation device.

  Thus, an AC traffic calculation system including the AC traffic calculation apparatus according to any one of claims 1 to 4 and a node can be realized.

  The invention described in claim 7 is a program for causing the AC traffic calculation apparatus, which is a computer, to execute the AC traffic calculation method according to claim 6.

  By doing so, it is possible to cause a general computer to execute the AC traffic calculation method according to claim 6.

  According to the present invention, when an estimated value of the amount of AC traffic between nodes in a network is calculated, the estimation accuracy can be improved and the calculation time can be reduced.

<Overview>
Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described. First, the outline of the AC traffic calculation process by the AC traffic calculation apparatus according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 and FIG. 2 are diagrams conceptually explaining an outline of an AC traffic calculation process by the AC traffic calculation apparatus of the present embodiment.

  Here, the AC traffic calculation device is an example in which the estimated value of the AC traffic amount between any two nodes 20 (20A, 20B, 20C, 20D) in the communication network (network) 40 shown in FIG. 1 is calculated. Explained. First, the AC traffic calculation apparatus (1) uses the Gravity method based on the IF (interface) unit traffic information 131 and the path information 132 of the communication network 40 to determine the AC traffic volume between the nodes 20 of the communication network 40. An initial value tg of the estimated value is calculated. This IF unit traffic information 131 is information indicating the input / output traffic amount of each node 20 in the communication network 40 in units of interfaces. Further, the path information 132 is information indicating, for each flow in the communication network 40, the identification information of the originating node and the destination node of the flow, and the identification information of the interface of the node 20 through which the flow passes. is there. That is, the route information 132 is information describing the topology in the communication network 40 and the link through which the flow passes through the identification information of the interfaces at both ends of the link.

AC traffic computing device, node 20 of Figure 1 (20A, 20B, 20C, 20D) initial value tg _m initial value tg (estimated value of the traffic volume of flow m in the communication network 40 of the estimated value of the AC traffic during 1), the six AC traffic amounts shown in FIG. 1 (the AC traffic amount indicates a reciprocal flow, so the actual traffic amount of a total of 12 flows) is calculated. Then, the initial value tg, which is a set of the calculated initial values tg _m of the traffic amount of each flow, is used as the flow identification information, the identification information of the originating (starting) node and the terminating (ending) node of the flow. And recorded in the AC traffic information 133 in association with. For example, the information indicated by ID “1” in FIG. 1 is recorded in the AC traffic information 133 as the estimated value tg ₁ of the AC traffic amount of the flow 1.

The value of the initial value tg of the estimated value of the AC traffic volume calculated in this way is not necessarily close to the actual traffic volume. Therefore, the AC traffic calculation device corrects the initial value tg of the estimated value of the AC traffic amount (2). As shown in FIG. 2, the correction here is performed by narrowing down, for each initial value tg _m of the estimated value of the traffic amount of each flow, a value that is clearly excessive.

First, the AC traffic calculation device is: The initial value tg _m of the estimated value of the traffic amount that is an excessive value is corrected to “x _i (IF unit traffic amount) / F _i (the number of flows of link i)”. For example, the AC traffic calculation device pays attention to a certain link i in the communication network 40 of FIG. 1, and the IF unit traffic information for the initial value tg _m of the estimated value of the traffic amount of the flow m accommodated in the link i. Referring to 131, it is determined whether or not the IF unit traffic amount x _i of link _i is exceeded. Here, when the initial value tg _m of the estimated traffic amount exceeds the IF unit traffic amount x _i of the link i, the calculated initial value tg _{m of} the traffic amount is an excessive value. Since it is clear, this value is corrected to “x _i (IF unit traffic amount) / F _i (flow number of link i)”. Such processing is performed for each flow of each link in the communication network 40.

Next, as shown in FIG. The initial value tg _m of the estimated traffic amount is equal to or less than the IF unit traffic amount x _{i of the} link i and exceeds the traffic amount threshold T _low, and is corrected by the TomoGravity method. On the other hand, 3. If the initial value tg _m of the estimated traffic amount is less than or equal to the AC traffic amount threshold T _low (for example, the threshold T _low is infinitely close to “0”), no correction is made. In other words, the AC traffic calculation device excludes the initial value tg _m of the calculated estimated traffic amount that is relatively small and is not excessive, and is not subject to correction by the TomoGravity method. Other initial values tg _m are subject to correction by the TomoGravity method.

By doing so, the AC traffic calculation device can reduce the calculation time by the TomoGravity method while improving the estimation accuracy of the AC traffic volume in the calculation process of the estimated value of the AC traffic volume. In addition, when the IF unit traffic information 131 of the communication network 40 is represented by a vector, x, the route information 132 is represented by a matrix (routing matrix) A, and the estimated value of the AC traffic amount is represented by a vector t. The relationship is as shown in the following equation (2). Expression (3) is an expression showing an example of Expression (2) when the number of IFs is 3 and the number of flows is 3. In the TomoGravity method, the initial value tg of the estimated value of the AC traffic amount calculated by the Gravity method is calculated based on the assumption that the AC traffic amount in the communication network 40 has a distribution close to the gravity model. The value t is corrected to satisfy 2).

<Configuration>
Here, a configuration example of a system (AC traffic calculation system) including such an AC traffic calculation device will be described. FIG. 3 is a diagram illustrating a configuration example of a system including the AC traffic calculation apparatus according to the present embodiment.

  As shown in FIG. 3, the system includes a terminal device 30, a communication network 40, and an AC traffic calculation device 10. The communication network 40 is a network for performing data communication between terminal devices 30 such as a PC (Personal Computer), and includes a plurality of nodes 20. The communication network 40 is, for example, IP (Internet Protocol) or MPLS (Multi-Protocol Label Switching), and the node 20 is, for example, an IP router or a router for MPLS. The AC traffic calculation apparatus 10 acquires path information 132 and IF unit traffic information 131 in the communication network 40 from the node 20 and calculates an estimated value of the AC traffic volume between the nodes 20 of the communication network 40.

  The configuration of such an AC traffic calculation device 10 will be described with reference to FIG. FIG. 4 is a diagram showing the configuration of the AC traffic calculation apparatus of FIG.

  As shown in FIG. 4, the function of the AC traffic calculation device 10 is large, and is divided into an input / output unit 11, a processing unit 12 and a storage unit 13. The input / output unit 11 receives inputs such as IF unit traffic information 131 and route information 132 of the communication network 40. The processing unit 12 controls the AC traffic calculation apparatus 10 as a whole, and here mainly calculates and corrects the initial value of the estimated value of the AC traffic amount. The storage unit 13 stores IF unit traffic information 131, route information 132, and the like that are referred to when calculating the estimated value of the AC traffic volume. The input / output unit 11 includes a communication interface with the communication network 40 and an input / output interface for performing data input / output with an external device. The processing unit 12 is realized by a program execution process by a CPU (Central Processing Unit) included in the AC traffic calculation device 10, a dedicated circuit, or the like. Further, the storage unit 13 includes a storage medium such as a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), and a flash memory. When the AC traffic calculation device 10 is realized by a program execution process, the storage unit 13 stores a program for realizing the function of the AC traffic calculation device 10. The AC traffic calculation device 10 receives input information such as a keyboard and a mouse for inputting various instructions to the AC traffic calculation device 10 and various information stored in the storage unit 13 of the AC traffic calculation device 10. An output device such as a liquid crystal monitor for output may be connected.

  The processing unit 12 includes an information collection unit 121, an AC traffic calculation unit 122, and an AC traffic output unit 126.

  For example, the information collection unit 121 collects IF unit traffic information 131 of each node 20 and route information 132 of the communication network 40 from the node 20 of the communication network 40 of FIG. . The collected IF unit traffic information 131 and route information 132 are stored in the storage unit 13.

  The AC traffic calculation unit 122 refers to the IF unit traffic information 131 and the path information 132 and performs calculation processing of an estimated value of the AC traffic amount between the nodes 20 of the communication network 40. The AC traffic calculation unit 122 includes an initial value calculation unit 123, an initial value correction unit 124, and a traffic amount estimation unit 125.

The initial value calculation unit 123 refers to the IF unit traffic information 131 and the path information 132 and reads the traffic amount related to the interface of any two node pairs from the node group constituting the communication network 40. Then, the initial value tg of the estimated value of the AC traffic volume of each flow flowing through the node 20 is calculated by the Gravity method using the read traffic volume. The calculated initial value tg (a set of initial values tg _m for each flow) is recorded in the AC traffic information 133.

The initial value correction unit 124 corrects the initial value tg of the estimated value of the AC traffic amount. That is, the initial value correction unit 124 refers to the path information 132 and identifies the flow accommodated in the link for each link connecting the nodes 20 in the communication network 40. Then, the value of the initial value tg _m of the estimated value of the traffic volume for each flow that the identified, determines whether more than IF unit traffic volume x _i of the link shown in IF unit traffic information 131. Here, when the value of the initial value tg _m is determined to exceed the IF unit traffic volume x _i of the link, the initial value correction section 124, the value of the initial value tg _m, the following equation (4) Correct to the indicated value. That is, the initial value correction unit 124 corrects the value of the initial value tg _{m to} the value of the average traffic amount per flow of the link.

(IF unit traffic amount x _{i of the} link) ÷ (number of flows F _i accommodated in the link) (4)

The traffic amount estimation unit 125 (1) route information A _c of the flow F _c , which is a set of flows whose initial value tg _m is equal to or greater than a predetermined threshold T _low , (2) the initial value tg _{m of the} flow F _c set _T c (G), and, (3) flow against _{F c} IF unit traffic information is a set of IF unit traffic information on _{X c,} to apply the TomoGravity method, traffic volume estimate for the flow _{F c} Calculate T _c ^est . That is, the traffic amount estimation unit 125 corrects the initial value tg _m by applying the TomoGravity method to a flow other than the flow F _fix in which the value is less than the predetermined threshold T _low among the traffic initial value tg _m. . Here, the route information A _c, the route information 132, the value of the initial value tg _m of the flow is obtained by extracting the routing information of the above flow a predetermined threshold T _low. The IF unit traffic information _Xc is obtained by removing the contribution of the set T _fix ^est of the initial value tg _m whose value is less than the predetermined threshold T _low from the IF unit traffic information 131.

  The TomoGravity method is described in Y. Zhang et al., “Fast, accurate computation of large-scale IP traffic matrics from link measurements”, ACM SGMETRICS 2003.

  By doing in this way, the traffic amount estimation part 125 can narrow down the flow which estimates the traffic amount by the TomoGravity method. That is, the traffic amount estimation unit 125 obtains an estimated value of the AC traffic amount by solving the equation shown in the above equation (2) by the TomoGravity method. Here, if the size (number of rows and columns) of the matrix A indicating the path information related to the flow to be estimated is large, the amount of calculation increases accordingly. Here, since the traffic amount estimation unit 125 narrows down the flow for estimating the AC traffic amount by the TomoGravity method, the amount of calculation can be reduced.

AC traffic output unit 126, the initial value of tg _m, initial value and the set _{T fix} ^est of tg _m, estimated value _{T c} ^est calculated by the traffic amount estimation unit 125 whose value is less than the predetermined threshold value _{T low} And output. The output destination here may be the storage unit 13 or an external device connected via the input / output unit 11.

  The storage unit 13 stores IF unit traffic information 131, route information 132, and AC traffic information 133.

  As described above, the IF unit traffic information 131 is information indicating the input / output traffic amount of each node 20 in the communication network 40 in units of interfaces (see FIG. 1).

  The path information 132 is information in which, for each flow in the communication network 40, the identification information of the originating node and the destination node of the flow, and the identification information of the interface of the node 20 through which the flow passes are shown in the order of passage. (See FIG. 1).

  The IF unit traffic information 131 and the route information 132 are referred to when the AC traffic calculation unit 122 calculates the AC traffic amount of the communication network 40.

The AC traffic information 133 is information indicating the traffic volume of each flow (see FIG. 1). The AC traffic information 133 includes, for example, identification information of the flow source node and the call destination node and the traffic volume of the flow. In this AC traffic information 133, first, an initial value tg (set of initial values tg _m for each flow) of the estimated value of the AC traffic amount calculated by the Gravity method is described, and then the initial value tg is corrected. The value is listed.

<Processing procedure>
Next, the processing procedure of the AC traffic calculation apparatus 10 will be described with reference to FIG. FIG. 5 is a flowchart showing a processing procedure of the AC traffic calculation apparatus of FIG. Here, the information collection unit 121 of the AC traffic calculation device 10 of FIG. 4 has already collected the IF unit traffic information 131 and the route information 132 from each node 20 of the communication network 40 of FIG. 1 and stores them in the storage unit 13. It shall be.

First, the initial value calculation unit 123 of the AC traffic calculation apparatus 10 refers to the IF unit traffic information 131 and the path information 132, and uses the Gravity method to initially estimate the AC traffic amount between the nodes 20 of the communication network 40. The value tg is calculated (S11). That is, for each flow in the communication network 40, the initial value tg _m of the estimated traffic amount is calculated for each flow. The calculation result at this time is stored in the AC traffic information 133 (see FIG. 1).

  Next, the initial value correcting unit 124 corrects the initial value tg of the estimated value of the AC traffic amount (S12). Details of the correction of the initial value tg at this time will be described later.

Then, the traffic amount estimation unit 125 sets the flow m whose initial value tg _m is equal to or higher than a predetermined threshold value T _low as the correction target set F _c, and the flow m whose value is lower than the predetermined threshold value T _{low. Is} a set F _fix of flows not to be corrected (S13). The threshold _{T low} is an IF unit traffic volume _{x i} the following values for each link, and is sufficiently close to the zero. By selecting the flow m to be corrected using such a threshold value T _low , the correction process of S14 is omitted for the initial value tg _{m of the} flow that is unlikely to be an excessive value. be able to.

Next, the traffic amount estimation unit 125 corrects the initial value tg _m for the set of flows F _c to be corrected (S14). The initial value tg _m is corrected by estimating the traffic amount using the TomoGravity method. Details of the correction processing here will also be described later.

Next, the AC traffic output unit 126 integrates the correction result T _c ^est obtained in S14 and the set T _fix ^est of the initial value tg _m of the flow F _fix that has been excluded from the correction target in S13 (S15). . The integrated information is output by the AC traffic output unit 126 to the storage unit 13 or an external device as an estimated value t of the AC traffic amount of the communication network 40.

By doing so, the AC traffic calculation unit 10 refers to the IF unit traffic volume x _i, clearly the initial value tg _m of the correction required flows can be corrected. In addition, the AC traffic calculation apparatus 10 can narrow down the flow for estimating the traffic amount using the TomoGravity method using the threshold value T _low . Therefore, it is possible to improve the estimation accuracy of the AC traffic amount and reduce the calculation amount by the TomoGravity method.

  Next, referring to FIG. 4 and using FIG. 6, the process of S12 of FIG. 5 (correction process of the initial value tg) will be described in detail. FIG. 6 is a flowchart showing S12 processing (initial value tg correction processing) of FIG.

First, the initial value calculation unit 123 of the AC traffic calculation apparatus 10 of FIG. 4 selects the link i of the communication network 40 of FIG. 1 with reference to the IF unit traffic information 131 (S120), and the link i of the selected link i is selected. It is determined whether or not the IF unit traffic amount x _i is less than a threshold value U _low (S121). Note that the threshold value U _low is equal to or less than the IF unit traffic amount of each link, and is infinitely close to 0 in principle.

Here, when the initial value correction unit 124 refers to the IF unit traffic information 131 and determines that the IF unit traffic amount x _{i of} the selected link i is less than the threshold value U _low , the initial value correction unit 124 indicates the flow accommodated in the link i. Information is extracted from the route information 132 (S122). That is, the initial value correction unit 124 is highly likely that the initial value tg _m of the flow of the link i whose IF unit traffic amount is less than the threshold value U _low is calculated as an excessive value. The flow of link i is specified.

On the other hand, it is IF unit traffic _{x i} of the link threshold _{U low} or (No in S121), and, if not executing the processing yet for all links (No in S126), selects the next link Then (S128), the process returns to S121. If the processing has already been completed for all the links (Yes in S126), the processing is terminated.

Following S122, the initial value correction section 124, an initial value tg flow m that is accommodated in the link i determines whether or not more than IF unit traffic volume _{x i} of the link i (S123). Here, the initial value tg _m is, when it is determined that more than IF unit traffic volume _{x i,} the initial value correction section 124, the initial value tg _m, x i (IF unit traffic volume) / _{F i} (link i The number of flows accommodated in

In other words, the fact that the initial value tg _m exceeds the value of the IF unit traffic volume x _i link i housed in the flow, the initial value tg _m is clearly excessive values. Therefore, the initial value correction unit 124 corrects such an initial value tg _m to an appropriate value.

  Next, the initial value calculation unit 123 determines whether or not processing has been executed for all the flows accommodated in the link i (S125), and if there is a flow that has not yet been processed (No in S125). ), Selects the next flow (S127), and returns to S123.

  On the other hand, the initial value calculation unit 123 executes the process for all the flows accommodated in the link i (Yes in S125) and executes the process for all the links of all the communication networks 40. If (Yes in S126), the process is terminated. If there is a link that has not yet been processed (No in S126), the next link is selected (S128), and the process returns to S121.

By doing so, the initial value calculation unit 123 can correct the initial value tg, that is, the initial value tg _m of the estimated value of the traffic amount of each flow, which is clearly excessive.

Next, the processing of S14 in FIG. 5 (correction processing of the initial value tg _m for the flow set F _c to be corrected) will be described in detail with reference to FIG. Figure 7 is a flowchart showing a (correction of the initial value tg _m for a set F _c of the flow to be corrected) process in S14 in FIG. Here, the traffic amount estimation unit 125 corrects the initial value tg _m that is determined to be corrected by the TomoGravity method in S13.

The traffic amount estimation unit 125 of the AC traffic calculation apparatus 10 of FIG. 4 is configured by flows included in the flow set F _c (a set of flows whose initial value tg _m is equal to or greater than a predetermined threshold T _low ) from the route information 132. creating a route information _{a c} that (S141). For example, when the set F _c is flows 1 and 3 and the set F _fix is flow 2, the traffic amount estimation unit 125 includes information on the flow 2 of the routing matrix A (route information) in the above-described equation (3) ( The information in the second column) is deleted, and the route information _Ac is created.

Next, the traffic amount estimation unit 125 calculates an initial value T _c (G) obtained by extracting the initial value tg _{m of the} flow included in the flow set F _c from the initial value tg (S142).

Then, the traffic amount estimation unit 125 creates IF unit traffic information X _c by removing the contribution of T _fix ^est included in the flow set F _fix from the IF unit traffic information 131 (IF unit traffic information X) ( S143). For example, when the set F _fix is the flow 2 and this flow passes through the IF 2 and 3 of the node 20, the traffic amount estimation unit 125 sets the IF unit traffic amount value of the IF 2 and 3 indicated in the IF unit traffic information 131. The IF unit traffic information _Xc is created by subtracting the values of the initial values tg ₁ and tg ₂ (that is, the initial values tg _{m of the} flows ₁ and ₂ ).

Next, the traffic amount estimation unit 125 applies the TomoGravity method to the IF unit traffic information X _c , the route information A _c and the initial value T _c (G) to calculate the estimated value T _c ^est (S144). ).

By doing so, the traffic estimation unit 125, among the initial values tg _m, it is possible to perform the calculation process to narrow down the flow calculation processing is required by TomoGravity method. That is, the amount of calculation by the TomoGravity method can be reduced.

  According to the AC traffic calculation apparatus 10 described above, it is possible to improve the estimation accuracy of the AC traffic volume and reduce the calculation time by the TomoGravity method in the calculation process of the AC traffic volume.

  In the above-described embodiment, the initial value calculation unit 123 of the AC traffic calculation device 10 further executes the correction process shown in FIG. 8 in addition to the correction process shown in FIG. 6 in the correction of the initial value tg in FIG. You may make it do. FIG. 8 is a flowchart showing an initial value correction process of the AC traffic calculation apparatus of FIG.

Here, the AC traffic calculation apparatus 10 includes a route reachability confirmation unit (not shown) that determines whether or not there is route reachability of each flow of the communication network 40 (see FIG. 1) from the route information 132, and route arrival. It is assumed that a second initial value correction unit (not shown) that corrects the value of the initial value tg _m related to the flow determined to be non-existent to 0 is provided. Here, “having route reachability” means that at least one route (successive link (or interface) from the node 20 to another node 20) between the nodes 20 in the communication network 40 on the route information 132. "No route reachability" means that there is no route between the nodes 20 in the communication network 40. That is, when there is no route reachability of a certain flow, the traffic amount of the flow is “0”.

The AC traffic calculation apparatus 10 extracts the flow information of the communication network 40 from the route information 132 (S1201), and confirms the route reachability of this flow (S1202). Here, when it is determined that there is no route reachability (No in S1202), the second initial value correction unit uses the initial value tg _m (recorded in the AC traffic information 133) calculated by the initial value calculation unit 123 as “ It is updated to “0” (S1203). On the other hand, when there is route reachability of this flow (Yes in S1202), the next flow is selected (S1205), and the process returns to S1201. When processing is executed for all the flows (Yes in S1204), the processing ends. If there is a flow that has not yet been processed (No in S1204), the next flow is selected (S1205), and S1201. Return to.

By doing in this way, the value of the flow whose traffic volume is clearly “0” can be set to “0” with respect to the initial value tg _m in the AC traffic information 133. Therefore, in the calculation process of the AC traffic volume, The estimation accuracy of the AC traffic volume can be improved and the calculation volume can also be reduced.

  Note that the process shown in FIG. 8 may be performed after the process shown in FIG. 6 is executed, or may be executed instead of the process shown in FIG.

Further, in FIG. 4 of the embodiment described above, as a target initial value correction section 124 IF unit traffic volume x _i link less than the threshold value U _low alternating traffic calculation unit 10, and performing S122 and subsequent steps However, the processing after S122 may be executed for all links.

Further, S123 Oite 6, the initial value tg _m flow m that is accommodated in the link i is, when more than IF unit traffic volume _{x i} of the link i, the initial value correction section 124, an initial value tg _m it may be the IF unit traffic volume x _i themselves for this link i.

  The AC traffic calculation apparatus 10 according to the present embodiment can be realized by a program for executing the processing as described above, and the program is stored in a computer-readable recording medium (CD-ROM or the like) and provided. Is possible.

It is the figure which demonstrated notionally the outline | summary of the AC traffic calculation process by the AC traffic calculation apparatus of this Embodiment. It is the figure which demonstrated notionally the outline | summary of the AC traffic calculation process by the AC traffic calculation apparatus of this Embodiment. It is the figure which showed the structural example of the system containing the alternating current traffic calculation apparatus of this Embodiment. It is the figure which showed the structure of the alternating current traffic calculation apparatus of FIG. It is the flowchart which showed the process sequence of the alternating current traffic calculation apparatus of FIG. 6 is a flowchart showing S12 processing (initial value tg correction processing) of FIG. 5; 6 is a flowchart showing the processing of S14 in FIG. 5 (processing for correcting the initial value tgm for the set of flows Fc to be corrected). 5 is a flowchart showing an initial value correction process of the AC traffic calculation apparatus of FIG. 4. It is the figure explaining the alternating current traffic estimation method used as a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 AC traffic calculation apparatus 11 Input / output part 12 Processing part 13 Storage part 20 Node 30 Terminal device 40 Communication network 121 Information collection part 122 AC traffic calculation part 123 Initial value calculation part 124 Initial value correction part 125 Traffic amount estimation part 126 AC traffic Output unit 131 IF unit traffic information 132 Route information 133 AC traffic information

Claims (7)

An AC traffic calculation device that calculates an estimated value of the traffic volume between two arbitrary nodes in a network,
For each interface identification information of each node constituting the network, interface unit traffic information indicating an input / output traffic amount of the interface, and identification information of a start node and an end node of the flow for each flow flowing through the network And a storage unit that stores path information indicating identification information of an interface that passes between a start point node and an end point node in the flow,
An input unit for receiving input of the interface unit traffic information and route information;
With reference to the path information, an arbitrary pair of two nodes is selected from a group of nodes constituting the network, and for each of the selected pair of nodes, the traffic related to the interface of the pair of nodes from the interface unit traffic information. An initial value calculation unit that reads an amount and calculates an initial value tg that is a set of initial values tg _m of the estimated value of the traffic amount of each flow in this network by the Gravity method using the read traffic amount;
For each link connecting nodes in the network with reference to the path information, a flow accommodated in the link is specified, and an initial value tg _m of the estimated traffic amount of the specified flow is determined. value, it is determined whether the exceeding interface unit traffic volume x _i of the link shown in the interface unit traffic information, when more than interface unit traffic volume x _i of the link, the value of the initial value tg _m , An initial value correction unit that performs an initial value correction process for correcting to a value represented by the following formula (1)
(Interface unit traffic amount x _{i of the} link) ÷ (Number of flows F _i accommodated in the link) Equation (1)
(1) Route information A _c obtained by extracting route information of a flow whose initial value tg _m is equal to or greater than the predetermined threshold T _low from the route information, and (2) the value of the initial value tg _m There the predetermined threshold value _{T low} or more initial values tg _m of the set _{T c (G), (3} ) from the interface unit traffic information, a set T of the initial value tg _m whose value is less than the predetermined threshold value _{T low} a traffic amount estimation unit that calculates an estimated value T _c ^est of a traffic amount of a flow equal to or greater than the predetermined threshold T _low by a TomoGravity method using the interface unit traffic information X _{c from} which the contribution of the _fix ^est is removed;
Of the initial value tg _m, a set T _fix ^est of the initial value tg _m whose value is less than said predetermined threshold value T _low, a value obtained by integrating the above calculated estimated value T _c ^est, the network An AC traffic calculation apparatus comprising: an AC traffic output unit that outputs an estimated value of a traffic amount of a flow at any two nodes. The initial value correction unit
Extracting a link whose traffic volume in the link is less than a predetermined threshold U _low from links connecting nodes in the network, and performing the initial value correction process on the extracted link; The AC traffic calculation apparatus according to claim 1. A route reachability confirmation unit that refers to the route information and determines whether or not each flow has route reachability; and
Of the tg _m calculated by the initial value correction unit, a second initial value correction unit that corrects the value of tg _m related to the flow determined to be non-reachable by the route reachability confirmation unit to 0 The AC traffic calculation apparatus according to claim 1, further comprising: an AC traffic calculation apparatus according to claim 1. The AC traffic calculation device is:
A route reachability confirmation unit that refers to the route information and determines whether or not each flow has route reachability,
Instead of the initial value correction unit,
For each link connecting nodes in the network with reference to the path information, a flow accommodated in the link is specified, and an initial value tg _m of the estimated traffic amount of the specified flow is determined. 2. A second initial value correction unit that corrects a value of tg _m related to a flow that is determined to have no route reachability by the route reachability confirmation unit, among values, to 0. 5. The AC traffic calculation apparatus according to claim 2.   The AC traffic calculation apparatus according to any one of claims 1 to 4, the path information and interface unit traffic information in the communication network are collected, and the collected path information and interface unit traffic information are An AC traffic calculation system comprising: a node that transmits in response to a request from an AC traffic calculation device. An AC traffic calculation device that calculates an estimated value of the traffic volume of a flow between any two nodes in the network,
For each interface identification information of each node constituting the network, interface unit traffic information indicating an input / output traffic amount of the interface, and identification information of a start node and an end node of the flow for each flow flowing through the network Receiving a path information indicating identification information of an interface that is passed between the start node and the end node in the flow; and
With reference to the path information, an arbitrary pair of two nodes is selected from a group of nodes constituting the network, and for each of the selected pair of nodes, the traffic related to the interface of the pair of nodes from the interface unit traffic information. Reading an amount and calculating an initial value tg, which is a set of initial values tg _m of estimated traffic amounts of each flow in this network, by the Gravity method using the read traffic amount;
For each link connecting nodes in the network with reference to the path information, a flow accommodated in the link is specified, and an initial value tg _m of the estimated traffic amount of the specified flow is determined. value, it is determined whether the exceeding interface unit traffic volume x _i of the link shown in the interface unit traffic information, when more than interface unit traffic volume x _i of the link, the value of the initial value tg _m Performing an initial value correction process for correcting to a value represented by the following expression (1);
(Interface unit traffic amount x _{i of the} link) ÷ (Number of flows F _i accommodated in the link) Equation (1)
(1) Route information A _c obtained by extracting route information of a flow whose initial value tg _m is equal to or greater than the predetermined threshold T _low from the route information, and (2) the value of the initial value tg _m There the predetermined threshold value _{T low} or more initial values tg _m of the set _{T c (G), (3} ) from the interface unit traffic information, a set T of the initial value tg _m whose value is less than the predetermined threshold value _{T low} calculating an estimated value T _c ^est of a traffic amount of a flow equal to or greater than the predetermined threshold T _low by a TomoGravity method using the interface unit traffic information X _{c from} which the contribution of the _fix ^est is removed;
Of the initial value tg _m, a set T _fix ^est of the initial value tg _m whose value is less than said predetermined threshold value T _low, a value obtained by integrating the above calculated estimated value T _c ^est, the network An AC traffic calculation method that executes a step of outputting as an estimated value of a traffic amount of a flow in any two nodes.   The program for making the said AC traffic calculation apparatus which is a computer perform the AC traffic calculation method of Claim 6.

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