JP2009260890A - Communication band calculation method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To calculate a communication band upper limit value in consideration of traffic of a detour path even if traffic on each node pair is unknown. <P>SOLUTION: A data acquisition section 21 obtains from an OS 10 path information indicating a communication link for an active path and a detour path to be used for each node pair, and traffic information indicating an observation traffic volume of traffic generated from the active path passing through a target communication link. A communication band calculation section 24 generates an observation traffic volume restriction condition relating to the observation traffic volume of the target communication link and a traffic demand restriction condition relating to a traffic demand in each node pair, generates an objective function relating to the traffic volume of the target communication link, and calculates a maximum value of the objective function when the observation traffic volume restriction condition and traffic demand restriction condition are established, as a communication band upper limit value of the target communication link. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication technique, and more particularly to a technique for calculating a communication band that will be required in the future.

In managing a communication network, a technique for accurately calculating a communication band necessary for ensuring traffic sufficiency in the future is required for an arbitrary communication link connecting node pairs.
When calculating the communication bandwidth that will be required in the future, from the viewpoint of accuracy with respect to the calculation result, it is necessary to consider not only the working path that is selected when there is no failure but also the traffic of the bypass path that is selected when there is a failure. Necessary. Also, in the communication network, information on the working path and the detour path for forwarding traffic is given, and traffic flowing through the working path in a situation where there is no failure is observed on the communication link, but each Source-Destination In many cases, the traffic flowing through a node pair is unknown.

  As a technique for calculating the communication bandwidth of the communication path, there is a method of deriving the upper limit value of traffic using a trivial solution, such as assuming the maximum value in the communication link of traffic flowing in the reverse direction in a ring network. However, the solution obtained by this method merely obtains the upper limit of the communication bandwidth required for the working path, and does not consider the traffic due to the detour path selected at the time of failure. In some cases, an excessive amount of bandwidth may be calculated.

  Conventionally, as a technique for estimating the traffic flowing in each Source-Destination node pair, a method called Network Tomography for estimating the AC traffic of the Source-Destination node pair based on the information of the traffic flowing in the communication link has been proposed (for example, non- (See Patent Document 1). Therefore, a method for obtaining a communication band in consideration of the traffic of the detour path using the AC traffic estimated by this Network Tomography is also conceivable.

Rui Castro et al., "Network Tomography: Recent Development", Statistical Science, Vo1.19, No.3, pp.499-517 (2004) Hiroshi Konno, "Linear Programming", Okakensha Publishers (1987)

However, the AC traffic required by such network tomography is obtained using maximum likelihood estimation based on a large amount of past information, and does not guarantee the upper limit value of the necessary bandwidth. Therefore, there is a problem that the obtained AC traffic cannot be used as it is as an upper limit value of a communication band that will be required in the future.
The present invention is for solving such a problem, and a communication band calculation method capable of calculating a communication band upper limit value considering the traffic of a detour path even when the traffic flowing in each node pair is unknown. And to provide an apparatus.

  In order to achieve such an object, the communication bandwidth calculation method according to the present invention is an arbitrary communication network on a communication network including a plurality of nodes and a plurality of communication links that connect node pairs including these nodes. A communication band calculation method used in a communication band calculation device for calculating a communication band upper limit value in a target communication link, wherein the data acquisition unit indicates path information indicating a communication link through which a working path and a detour path used in each node pair pass Data acquisition step for acquiring traffic information indicating the observed traffic volume of traffic generated from the working path passing through the target communication link, and storing the traffic information in a storage unit; and a communication band calculating unit including path information, traffic information, The amount of observed traffic on the target communication link and the traffic on the working path that passes through the target communication link Based on the relationship, the observed traffic volume constraint generation step for generating the observed traffic volume constraint condition related to the observed traffic volume of the target communication link, and the communication bandwidth calculation unit refers to the path information, and A traffic demand constraint condition generation step for generating a traffic demand constraint condition related to traffic demand, and a communication bandwidth calculation unit, referring to the path information, based on the traffic demand in the working path and the detour path via the target communication link, An objective function generation step for generating an objective function related to the traffic volume of the target communication link, and the communication band calculation unit determines the maximum value of the objective function when the observed traffic volume constraint condition and the traffic demand constraint condition are satisfied. Objective function maximum value calculating step There.

At this time, the set of communication links in the communication network is A, the target communication link is a, the observed traffic value of a is Ca, the set of node pairs in which traffic demand occurs is D, and the pair of nodes belonging to D is generated by d and d. If the unknown traffic demand is Xd, the flag that becomes 1 when the working path of d passes through a and becomes 0 when the working path does not pass through a is yd ^a , Σ _d∈D Xd · yd ^a = Ca, for aεA may be used.

  Further, when a set of node pairs in which traffic demand occurs is D, a node pair belonging to D is d, and an unknown traffic demand generated by d is Xd, Xd ≧ 0, for dεD is used as a traffic demand constraint condition. May be.

Also, the set of communication links in the communication network is A, the target communication link is a, the set of node pairs that generate traffic demand is D, the pair of nodes belonging to D is d, and the unknown traffic demand generated by d is Xd, d yd ^a flag which becomes 0 when no via one next to a when the working path via a, a flag bypass path d is 0 when no via one next to a when passing through the a In the case of zd ^a , Σ _dεD Xd · (yd ^a + zd ^a ) may be used as the objective function.

  In addition, the communication band calculation device according to the present invention provides a communication band upper limit value in an arbitrary target communication link on a communication network including a plurality of nodes and a plurality of communication links connecting node pairs including these nodes. Is a communication band calculation device for calculating the path information indicating the communication link through which the working path and the detour path used in each node pair pass, and the observed traffic amount of the traffic generated from the working path passing through the target communication link Referring to the data acquisition unit that acquires the traffic information and stores it in the storage unit, the path information and the traffic information, the observed traffic volume of the target communication link and the traffic demand on the working path via the target communication link Based on the relationship between the observed traffic volume and the observed traffic volume constraint on the observed traffic volume of the target communication link. The traffic demand constraint condition generation step for generating traffic demand constraint conditions related to traffic demand in each node pair with reference to the path information, and the communication bandwidth calculation unit refers to the path information and passes through the target communication link Based on the traffic demand on the working path and detour path, an objective function related to the traffic volume of the target communication link is generated, and the maximum value of the objective function when the observed traffic volume constraint condition and traffic demand constraint condition is satisfied A communication bandwidth calculation unit that calculates the upper limit value.

At this time, the set of communication links in the communication network is A, the target communication link is a, the observed traffic value of a is Ca, the set of node pairs in which traffic demand occurs is D, and the pair of nodes belonging to D is generated by d and d. If the unknown traffic demand is Xd, the flag that becomes 1 when the working path of d passes through a and becomes 0 when the working path does not pass through a is yd ^a , Σ _d∈D Xd · yd ^a = Ca, for aεA may be used.

  Further, when a set of node pairs in which traffic demand occurs is D, a node pair belonging to D is d, and an unknown traffic demand generated by d is Xd, Xd ≧ 0, for dεD is used as a traffic demand constraint condition. May be.

Also, the set of communication links in the communication network is A, the target communication link is a, the set of node pairs that generate traffic demand is D, the pair of nodes belonging to D is d, and the unknown traffic demand generated by d is Xd, d yd ^a flag which becomes 0 when no via one next to a when the working path via a, a flag bypass path d is 0 when no via one next to a when passing through the a In the case of zd ^a , Σ _dεD Xd · (yd ^a + zd ^a ) may be used as the objective function.

  According to the present invention, it is possible to calculate a more accurate communication band upper limit value considering the traffic of the detour path even when the traffic flowing through each node pair is unknown.

Next, embodiments of the present invention will be described with reference to the drawings.
First, a communication band calculation device according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of a communication band calculating apparatus according to an embodiment of the present invention.

In FIG. 1, a communication network 50 is a network composed of a plurality of nodes and a plurality of communication links connecting node pairs composed of these nodes.
The operation system (hereinafter referred to as OS) 10 includes an information processing device such as a server device, and from a node in the communication network 50, when there is network topology information, the traffic volume of each communication link, and whether there is a failure in each communication link. Various network information such as series information is collected by the network data management unit 11, stored in a network information database (hereinafter referred to as network information DB) 12, and in response to a request from the communication bandwidth calculation device 20, the network data management unit 11 has a function of providing arbitrary network information in the network information DB 12.

The communication band calculation device 20 includes an information communication device such as a server device, and performs communication based on various functions acquired from the OS 10 according to instructions from the management terminal 30 and a function for performing data communication with the OS 10 and the management terminal 30. It has a function of calculating a communication band required for an arbitrary target communication link on the network 50, that is, a communication band upper limit value.
The management terminal 30 includes an information processing device such as a PC terminal used by a network operator or a designer. The control unit 31 instructs the communication bandwidth calculation device 20 to calculate the communication bandwidth and is obtained as a calculation result. The communication band 50 is displayed on the screen by the display unit 32, or has a function of performing an operation management process and a network design process of the communication network 50 using the communication band obtained as a calculation result.

  This embodiment shows path information indicating a communication link through which a working path and a detour path used in a node pair constituting the communication network 50 pass, and an observed traffic amount of traffic generated from the working path passing through the target communication link. The traffic information is acquired from the OS 10, and the observed traffic volume constraint condition regarding the observed traffic volume of the target communication link and the traffic demand constraint condition regarding the unknown traffic demand at each node pair are generated, and the traffic volume of the target communication link And the maximum value of the objective function when the observed traffic volume constraint condition and the traffic demand constraint condition are satisfied is calculated as the communication band upper limit value of the target communication link.

[Configuration of the embodiment]
Next, the configuration of the communication band calculation device according to the embodiment of the present invention will be described with reference to FIG.
The communication band calculation device 20 includes, as main functional units, a data acquisition unit 21, a path information database (hereinafter referred to as a path information DB) 21, a traffic information database (hereinafter referred to as a traffic information DB) 22, and a communication band calculation. A portion 24 is provided.

  The data acquisition unit 21 periodically or in response to an instruction from the communication band calculation unit 24, in the network information DB 12 related to the communication network 50, path information indicating a communication link through which a working path and a detour path used in each node pair pass. And the traffic information indicating the observed traffic volume of the traffic generated from the working path passing through the target communication link, and storing them in the path information DB 22 and the traffic information DB 23, respectively.

FIG. 2 is an explanatory diagram showing a partial configuration of the communication network. Here, as a partial configuration of the communication network 50, the node A (n1), the node B (n2), and the node C (n3) and a communication link a1 that connects the nodes AB, a communication link a2 that connects the nodes AC, In addition, a communication link a3 connecting between the nodes BC is shown.
As communication paths used for node pair data communication, it is possible to superimpose a plurality of working paths selected at normal time without a failure and detour paths selected at the time of a failure on the communication links a1 to a3. In the example of FIG. 2, a working path p12 between nodes AB and a detour path q13 between nodes AC are superimposed on the communication path a1. In addition, a working path p13 between nodes AC and a detour path q12 between nodes AB are superimposed on the communication path a2, and a detour path q12 between nodes AB and a detour between nodes AC are superimposed on the communication path a3. A path p13 is superimposed.

The path information DB 22 has a function of storing path information acquired from the OS 10 by the data acquisition unit 21.
FIG. 3 is a configuration example of the path information, and a specific example of the path information in the configuration example of the communication network shown in FIG. 2 is shown. The path information includes a set of a node pair ID indicating an arbitrary node pair in the communication network 50, a working path information indicating a working path of the node pair, and a detour path information indicating a detour path of the node pair. Registered in the path information DB 22.

  In the working path information and the detour path information, in addition to the path IDs of the working path and detour path, the link IDs of communication links through which these paths pass are listed. As a result, regarding the node pair AB, it can be seen that the working path p12 passes through the communication link a1, and the detour path q12 passes through the communication links a2 and a3. As for the node pair AC, it can be seen that the working path p13 passes through the communication link a2, and the detour path q13 passes through the communication links a1 and a3.

The traffic information DB 23 has a function of storing traffic information acquired from the OS 10 by the data acquisition unit 21.
FIG. 4 is a configuration example of traffic information, and shows a specific example of path information in the configuration example of the communication network shown in FIG. The traffic information is composed of a pair of a communication link ID indicating an arbitrary communication link in the communication network 50 and an observed traffic amount by the working path observed in the communication link, and is registered in the traffic information DB 23 for each communication link. . For example, C1 is registered as the observed traffic amount of the communication link a1, and C2 and C3 are registered as the observed traffic amounts of the communication links a2 and a3.

  This observed traffic amount is the traffic amount observed in a state where no failure has occurred, and does not include the traffic amount generated by the detour path. The network information DB 12 of the OS 10 stores the traffic volume of each communication link as well as the presence / absence of the failure in time series. When acquiring traffic information from the OS 10, the traffic information indicates the observed traffic amount in the state where no failure has occurred. You can get as

  The communication band calculation unit 24 refers to the path information DB 22 and the traffic information DB 23 in response to an instruction from the management terminal 30, and observes the observed traffic amount of the target communication link and the unknown traffic of the working path passing through the target communication link. Based on the relationship with demand, a function for generating an observed traffic volume constraint condition regarding the observed traffic volume of the target communication link, and a traffic demand constraint condition regarding unknown traffic demand at each node pair are generated with reference to the path information DB 22 A function for generating an objective function related to the traffic volume of the target communication link based on the unknown traffic demand of the working path and the detour path passing through the target communication link with reference to the path information DB 22, and an observation When traffic volume constraint conditions and traffic demand constraint conditions are met That the maximum value of the objective function is calculated as the communication bandwidth upper limit of the target communication link, and a function of outputting to the management terminal 30.

Of the functional units of the communication band calculation device 20, the data acquisition unit 21 and the communication band calculation unit 24 are realized by an arithmetic processing unit in which the CPU and the program cooperate, and further by a communication circuit unit for data communication. .
The path information DB 22 and the traffic information DB 23 are realized from a storage device such as a hard disk or a memory. These may be realized by separate storage devices or may be realized by the same storage device.

[Operation of this embodiment]
Next, the operation of the communication band calculation device according to the embodiment of the present invention will be described with reference to FIG. FIG. 5 is a flowchart showing a communication band calculation process in the communication band calculation apparatus according to the embodiment of the present invention.
The communication band calculation unit 24 of the communication band calculation device 20 executes the communication band calculation process of FIG. 5 in response to an instruction from the management terminal 30.

  First, the communication band calculation unit 24 acquires path information related to each node pair from the path information DB 22 and also acquires an observed traffic volume related to the target communication link from the traffic information DB 23 (step 100). As for the target communication link, a link designated by an instruction from the management terminal 30 may be selected, or a link set in advance in a storage unit (not shown) may be selected. Hereinafter, a case where the communication link a1 is designated as the target communication link will be described as an example.

  Next, based on the acquired path information and observed traffic information, the communication band calculating unit 24 calculates the observed traffic amount C1 of the target communication link a1 and the unknown traffic demand on the working path via the target communication link a1. Based on the relationship, an observation traffic amount constraint condition relating to the observation traffic amount C1 of the target communication link a1 is generated (step 101).

  Since the observed traffic volume C1 of the target communication link a1 is the traffic volume observed in the state where no failure has occurred as described above, this observed traffic C1 includes all the traffics that pass through the target communication link a1. It is equal to the sum of traffic demand generated on the working path. Therefore, an observation traffic volume constraint condition related to the observation traffic volume C1 of the target communication link a1 can be generated from this relationship.

At this time, a node pair having a working path passing through an arbitrary target communication link can be searched from the working path information of the path information, and a flag yd indicating whether or not the working path passes through the target communication link a for each node pair d. it can be represented by ^a. Further, since the traffic demand generated in each node pair is unknown, the traffic demand may be defined as Xd for each node pair d.

Therefore, the set of communication links in the communication network 50 is A, the target communication link is a, the observed traffic value is Ca, the set between nodes where traffic demand occurs is D, and the nodes belonging to D are set d and d. unknown traffic demand Xd, if working path d is an yd ^a flag which becomes 0 when no via one next to a when passing through the a, observed traffic volume constraints, the following equation (1) Can be expressed as
_Σd∈D Xd · yd ^a = Ca, for a∈A (1)

Further, the communication band calculation unit 24 generates a traffic demand constraint condition related to unknown traffic demand in each node pair based on the acquired path information (step 102).
As described above, the traffic demand Xd of each node pair d is unknown, but its value is always 0 or more and never takes a negative value. Therefore, when the set of node pairs in which traffic demand occurs is D, the node pair belonging to D is d, and the unknown traffic demand generated by d is Xd, the traffic demand constraint condition can be expressed by the following equation (2). it can.
Xd ≧ 0, for dεD (2)

Further, the communication band calculation unit 24 calculates an objective function related to the traffic amount of the target communication link based on the unknown traffic demand in the working path and the detour path passing through the target communication link a1 based on the acquired path information. Generate (step 103).
The actual traffic volume in the target communication traffic a1 includes not only the working path but also the traffic volume generated from the detour path. Therefore, the maximum value of the total traffic demand of the working path and the detour path passing through the target communication path a1 corresponds to the communication band required for the target communication link, that is, the communication band upper limit value.

At this time, a node pair having a working path or a detour path passing through an arbitrary target communication link can be searched from the working path information or the detour path information of the path information. For this reason, whether or not the working path passes through the target communication link a for each node pair d can be represented by the flag yd ^a and whether or not the bypass path passes through the target communication link a for each node pair d. can the expressed flag zd ^a. Further, since the traffic demand generated in each node pair is unknown, the traffic demand may be defined as Xd for each node pair d.

Therefore, the set of communication links in the communication network 50 is A, the target communication link is a, the set of node pairs that generate traffic demand is D, the pair of nodes belonging to D is d, and the unknown traffic demand generated by d is Xd, d A flag that becomes 1 when the current working path passes through a and becomes 0 when it does not pass through ^a , and a flag that becomes 1 when the detour path of d passes through a and becomes 0 when not passing through a the case of a zd ^a, the objective function can be expressed by the following equation (3).
_Σd∈D Xd · (yd ^a + zd ^a ) (3)

  In this way, after generating the observed traffic volume constraint condition, the traffic demand constraint condition, and the objective function, the communication band calculation unit 24 is based on the linear programming (see Non-Patent Document 2 etc.), and these observed traffic volume The maximum value of the objective function when the constraint condition and the traffic demand constraint condition are satisfied is calculated as the communication band upper limit value of the target communication link a1 and output to the management terminal 30 (step 104), and a series of communication band calculation processes Exit.

[Effects of the present embodiment]
As described above, in the present embodiment, path information indicating the communication link through which the working path and the detour path used in the node pair constituting the communication network 50 pass, and observation of traffic generated from the working path through the target communication link. The traffic information indicating the traffic volume is acquired from the OS 0, and the observed traffic volume constraint condition regarding the observed traffic volume of the target communication link for which the communication band is calculated is generated, and the traffic demand regarding the unknown traffic demand in each node pair Generate constraint conditions, generate an objective function related to the traffic volume of the target communication link, and set the maximum value of the objective function when these observed traffic volume constraint conditions and traffic demand constraint conditions are met, the communication bandwidth upper limit of the target communication link Since it was calculated as a value, Even if the traffic flowing in the pair is not known, considering traffic roundabout path, it is possible to calculate a more accurate communication bandwidth limit.

Further, in this embodiment, the case where the traffic volume observed for the target communication link is used as an example of the observed traffic volume has been described as an example. However, in the endpoint node where traffic actually flows in and out, the traffic volume flowing in and out at the endpoint node It may be possible to observe the sum of
In such a case, the communication band calculation unit 24 generates a new constraint condition based on the relationship that the sum of the traffic demand Xd flowing in / out at the end node is equal to the inflow / outflow traffic observed at the end node. Then, the maximum value of the objective function when the new constraint condition, the observed traffic volume constraint condition and the traffic demand constraint condition are satisfied may be calculated as the communication band upper limit value of the target communication link.

In this embodiment, the case where the traffic volume observed for the target communication link is used as an example of the observed traffic volume has been described as an example. However, in the end point node where the traffic actually flows in and out, out of the above inflow traffic volume. In some cases, it is possible to observe the amount of traffic flowing through an arbitrary node pair.
In such a case, the communication bandwidth calculation unit 24 uses the traffic demand Xd of an arbitrary node pair d as the traffic demand constraint condition of Equation (2) described above and the traffic amount of the node pair d observed at the end node. A constraint condition of equality may be generated, and the maximum value of the objective function when the observed traffic volume constraint condition and the traffic demand constraint condition are satisfied may be calculated as the communication band upper limit value of the target communication link.

In this embodiment, when generating the observed traffic volume constraint condition, it is defined as being equal to the sum of the observed traffic of the target communication link and the traffic demand generated in all the working paths passing through the target communication link. A statistical multiple effect may be added to this definition.
When the amount of information changes greatly in time, such as the use of multimedia communication, particularly the Internet usage or moving image communication, the total communication speed is smoothed by multiplexing, for example, by the ATM method, which is constant compared to the STM method. It is possible to send a large amount of information in the bandwidth of, and such an effect is called “statistical multiple effect”.

Therefore, for example, for each combination of traffic to be superimposed on the target communication link, a reduction rate indicating the obtained statistical multiplexing effect is derived in advance, and obtained on the right side of Equation (1) described above on the target communication link. You may make it multiply a reduction rate. As a result, a communication bandwidth upper limit value that takes into account the statistical multiplexing effect can be obtained, and effective use of network resources can be realized.
The statistical multiplexing effect can be applied not only to the observation traffic amount constraint condition but also to the case of generating the objective function of the above-described equation (3) in the same manner as described above, and the same effect can be obtained. Become.

It is a block diagram which shows the structure of the communication band calculation apparatus concerning one embodiment of this invention. It is explanatory drawing which shows the partial structure of a communication network. It is a structural example of path information. It is a structural example of traffic information. It is a flowchart which shows the communication band calculation process in the communication band calculation apparatus concerning one embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... OS, 11 ... Network data management part, 12 ... Network information DB, 20 ... Communication band calculation apparatus, 21 ... Data acquisition part, 22 ... Path information DB, 23 ... Traffic information DB, 24 ... Communication band calculation part, 30 ... management terminal, 31 ... control unit, 32 ... display unit.

Claims (8)

A communication band used in a communication band calculation device that calculates a communication band upper limit value in an arbitrary target communication link on a communication network including a plurality of nodes and a plurality of communication links that connect a node pair including these nodes. A calculation method,
A data acquisition unit includes path information indicating a communication link through which a working path and a detour path used in each node pair pass, and traffic information indicating an observed traffic amount of traffic generated from the working path passing through the target communication link. A data acquisition step of acquiring and storing in the storage unit;
The communication band calculation unit refers to the path information and the traffic information, and based on the relationship between the observed traffic amount of the target communication link and the traffic demand in the working path that passes through the target communication link. An observation traffic volume constraint generation step for generating an observation traffic volume constraint condition regarding the observed traffic volume of the communication link;
The traffic bandwidth calculation unit generates a traffic demand constraint condition related to traffic demand in each node pair with reference to the path information, and a traffic demand constraint condition generation step;
The communication band calculation unit refers to the path information, and generates an objective function related to the traffic amount of the target communication link based on traffic demand on the working path and the detour path passing through the target communication link. Generation step;
The communication band calculating unit includes an objective function maximum value calculating step of calculating, as the communication band upper limit value, the maximum value of the objective function when the observed traffic volume constraint condition and the traffic demand constraint condition are satisfied. A communication bandwidth calculation method. In the communication band calculation method according to claim 1,
A set of communication links in the communication network is A, the target communication link is a, the observed traffic value of a is Ca, a set of node pairs that generate traffic demand is D, and a pair of nodes belonging to D is generated by d and d. Assuming that the unknown traffic demand is 1 when the working path of Xd and d passes through a and 0 when the working path does not pass through ^a, and yd ^a , the observed traffic volume constraint condition is as follows:
_Σd∈D Xd · yd ^a = Ca, for a∈A
A communication band calculation method characterized by using the above. In the communication band calculation method according to claim 1,
When a set of node pairs in which traffic demand occurs is D, a node pair belonging to D is d, and an unknown traffic demand generated in d is Xd, the traffic demand constraint condition is as follows:
Xd ≧ 0, for dεD
A communication band calculation method characterized by using the above. In the communication band calculation method according to claim 1,
A set of communication links in the communication network is A, the target communication link is a, a set of node pairs in which traffic demand occurs is D, a node pair belonging to D is d, and unknown traffic demand generated by d is Xd, d yd ^a flag which becomes 0 when no via one next to a when the working path via a, a flag bypass path d is 0 when no via one next to a when passing through the a If the zd ^a, as the objective function,
Σ _d∈D Xd · (yd ^a + zd ^a )
A communication band calculation method characterized by using the above. A communication band calculation device for calculating a communication band upper limit value in an arbitrary target communication link on a communication network including a plurality of nodes and a plurality of communication links connecting a node pair including these nodes,
Acquire and store path information indicating a communication link through which a working path and a detour path used in each node pair pass, and traffic information indicating an observed traffic amount of traffic generated from the working path via the target communication link A data acquisition unit to be stored in the unit;
Referring to the path information and the traffic information, based on the relationship between the observed traffic volume of the target communication link and the traffic demand on the working path passing through the target communication link, the observed traffic volume of the target communication link A traffic demand constraint condition generating step for generating a traffic demand constraint condition related to traffic demand in each node pair with reference to the path information;
The communication band calculation unit refers to the path information, generates an objective function related to the traffic amount of the target communication link based on traffic demand on the working path and the detour path passing through the target communication link, and A communication band calculation apparatus comprising: a communication band calculation unit that calculates a maximum value of the objective function as the communication band upper limit value when an observed traffic amount constraint condition and a traffic demand constraint condition are satisfied. In the communication band calculation device according to claim 5,
A set of communication links in the communication network is A, the target communication link is a, the observed traffic value of a is Ca, a set of node pairs that generate traffic demand is D, and a pair of nodes belonging to D is generated by d and d. Assuming that the unknown traffic demand is 1 when the working path of Xd and d passes through a and 0 when the working path does not pass through ^a, and yd ^a , the observed traffic volume constraint condition is as follows:
_Σd∈D Xd · yd ^a = Ca, for a∈A
A communication band calculation device using the above-described information. In the communication band calculation device according to claim 5,
When a set of node pairs in which traffic demand occurs is D, a node pair belonging to D is d, and an unknown traffic demand generated in d is Xd, the traffic demand constraint condition is as follows:
Xd ≧ 0, for dεD
A communication band calculation device using the above-described information. In the communication band calculation device according to claim 5,
A set of communication links in the communication network is A, the target communication link is a, a set of node pairs in which traffic demand occurs is D, a node pair belonging to D is d, and unknown traffic demand generated by d is Xd, d yd ^a flag which becomes 0 when no via one next to a when the working path via a, a flag bypass path d is 0 when no via one next to a when passing through the a If the zd ^a, as the objective function,
Σ _d∈D Xd · (yd ^a + zd ^a )
A communication band calculation device using the above-described information.

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