JP2014160906A - Device, method and program for network division - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a uniform communication load between partial networks after division, with an uneven distribution of an attribute of node connection relationship.SOLUTION: A network division device for dividing a network including a plurality of division target nodes into a first partial network and a second partial network includes: an acquisition unit for acquiring an index value, indicative of each communication load of the plurality of nodes, and information related to the connection relationship; and a distribution unit for distributing the plurality of nodes to the first partial network and the second partial network in a manner to make an uneven distribution between an external connection node connecting to a node outside the division target network and an internal connection node not connecting to the node outside the division target network, with an equalized communication load between the first partial network and the second partial network.

Description

  The present invention relates to a network dividing device, a network dividing method, and a network dividing program.

  2. Description of the Related Art Conventionally, a technique for managing a network constituted by various communication nodes by dividing the network into a plurality of partial networks is known. Examples of the communication node include various server devices, communication base stations, routers, hubs, and terminal devices.

  For example, Patent Document 1 describes a method of dividing a network into two by sequentially belonging each node on the network to one of the partial networks so that the AC traffic between the partial networks is maximized. Yes.

  Non-Patent Document 1 describes a method of performing network division in parallel network simulation for the purpose of equalizing processor loads and reducing the amount of communication between processors.

JP 2012-244575 A

"A Flexible Dynamic Partitioning Algorithm for Optimistic Distributed Simulation", Patrick Peschlow, Tobias Honecker, Peter Martini, University of Bonn, Department of Computer Science IV

  However, each of the above-mentioned documents does not describe uneven distribution of node connection relation attributes in the divided partial network.

  The present invention has been made in view of such circumstances, and an object of the present invention is to equalize the communication load between the divided partial networks and to make the connection relation attributes unevenly distributed. .

One aspect of the present invention is a network dividing device that divides a division target network including a plurality of nodes into a first partial network and a second partial network, and indicates an indicator of each communication load of the plurality of nodes An acquisition unit that acquires information about values and connection relations, and the communication load is equalized between the first partial network and the second partial network, and is connected to a node outside the division target network A distribution unit that distributes the plurality of nodes to the first partial network or the second partial network such that an external connection node and an internal connection node that is not connected to a node outside the division target network are unevenly distributed; It is a network dividing device provided.
In one aspect of the present invention, the distribution unit preferentially selects the external connection node for the first partial network and preferentially selects the internal connection node for the second partial network. Thus, the external connection node and the internal connection node may be unevenly distributed.
1 aspect of this invention WHEREIN: The said distribution part is the sum total value (2nd total value) of the said index value in the said 2nd partial network, and the total value (1st total value) of the said index value in the said 1st partial network. ) Is balanced so that communication load between the first partial network and the second partial network is distributed to the first partial network or the second partial network. May be equalized.
In this case, when the first total value is smaller than the second total value, the distribution unit is present if the external connection node that satisfies the first predetermined condition exists among unallocated nodes. An external connection node is allocated to the first partial network, and if it does not exist, an unallocated internal connection node satisfying the first predetermined condition is allocated to the first partial network, and the first total value is If the internal connection node satisfying the second predetermined condition exists among unallocated nodes when the second total value is greater than the second total value, the existing internal connection node is distributed to the second partial network; If it does not exist, unallocated external connection nodes that satisfy the second predetermined condition may be distributed to the second partial network.
Further, in this case, the first predetermined condition is an adjacent node of a node that has already been allocated to the first partial network, and the second predetermined condition is already allocated to the second partial network. It may be that it is an adjacent node of the selected node.
In these cases, the distribution unit is configured in a case where the first total value is smaller than the second total value and the external connection node that satisfies the first predetermined condition does not exist among unallocated nodes. Even if the difference obtained by subtracting the first total value from the second total value is equal to or smaller than the threshold value, the unallocated internal connection nodes satisfying the second predetermined condition are allocated to the second partial network. Even if the first total value is larger than the second total value and the internal connection node that satisfies the second predetermined condition does not exist among unallocated nodes, the first total If the difference obtained by subtracting the second total value from the value is equal to or smaller than a threshold value, unallocated external connection nodes that satisfy the first predetermined condition may be distributed to the first partial network.
In one aspect of the present invention, when the distribution unit distributes the external connection node to the first partial network, the distribution unit prioritizes a node having a large communication load related to communication with a node outside the division target network. When the external connection node is distributed to the second partial network, a node having a small communication load related to communication with a node outside the division target network may be preferentially distributed.
In one aspect of the present invention, the distribution unit distributes the external connection node according to a first rule based on a connection relationship with a node outside the division target network when distributing the external connection node to the first partial network. When selecting a connection node and allocating the external connection node to the second partial network, the external connection node may be selected according to a second rule having a tendency opposite to the first rule. .
In one aspect of the present invention, among the external connection nodes allocated to the second partial network, the external connection nodes allocated to the first partial network communicate with a network outside the division target network. In contrast, a signal instructing to delete a link to a network outside the division target network may be transmitted.
Another aspect of the present invention is a network division method for dividing a division target network including a plurality of nodes into a first partial network and a second partial network, each indicating a communication load of the plurality of nodes. An external connection that obtains an index value and information related to a connection relationship, equalizes a communication load between the first partial network and the second partial network, and connects to a node outside the division target network In the network partitioning method, the plurality of nodes are distributed to the first partial network or the second partial network so that nodes and internal connection nodes that are not connected to nodes outside the network to be divided are unevenly distributed.
Another aspect of the present invention is a network division program for dividing a network to be divided including a plurality of nodes into a first partial network and a second partial network in the computer, wherein the computer includes the plurality of nodes. Index values indicating the respective communication loads and information related to connection relations are acquired, the communication load is equalized between the first partial network and the second partial network, and the network outside the division target network The plurality of nodes are distributed to the first partial network or the second partial network so that the external connection nodes connected to the nodes and the internal connection nodes not connected to the nodes outside the division target network are unevenly distributed. A network partitioning program.

  According to one aspect of the present invention, it is possible to equalize the communication load among the divided partial networks and to make the attribute of the node connection relation unevenly distributed.

It is the figure which illustrated the whole image of the network NW including the network (division target network TNW) which the network division | segmentation apparatus 1 of 1st Embodiment makes into a division | segmentation object. It is a figure which shows the connection relation of the some node contained in the division | segmentation object network TNW. 3 is a configuration diagram illustrating an example of a functional configuration of a network dividing device 1. FIG. It is a figure which shows an example of the information containing the information regarding the amount of flow management information acquired from each node, and a connection relationship. It is a figure which shows an example of the information to which the attribute of the connection relation was provided by the attribute discrimination | determination part. It is an example of the flowchart which shows the flow of the distribution process performed by the distribution process part 40 which concerns on 1st Embodiment. It is an example of the flowchart which shows the flow of the distribution process performed by the distribution process part 40 which concerns on 2nd Embodiment. It is an example of the flowchart which shows the flow of the distribution process performed by the distribution process part 40 which concerns on 3rd Embodiment. FIG. 9 is an example of a flowchart showing a flow of processing when an external connection node is selected in step S304 of FIG. FIG. 9 is an example of a flowchart showing a processing flow when selecting an external connection node in step S314 of FIG. 8; It is the figure which illustrated the link which can be deleted in the network NW where division was performed.

  Hereinafter, embodiments of a network dividing device, a network dividing method, and a network dividing program according to the present invention will be described with reference to the drawings.

<First Embodiment>
[Overview and configuration]
FIG. 1 is a diagram illustrating an overall image of a network NW including a network to be divided by the network dividing device 1 according to the first embodiment (divided target network TNW). For example, the network NW is expanded in a tree shape starting from a root network, and is connected in order to a parent network, a division target network TNW, and a child network. The network NW is, for example, Ethernet (registered trademark). The network dividing device 1 is arranged in a parent network positioned above the division target network, for example. However, the present invention is not limited to this, and the network dividing device 1 may be arranged at an arbitrary position in the network NW. The network dividing device 1 divides the division target network TNW into at least two partial networks PNW1 and PNW2.

  FIG. 2 is a diagram illustrating a connection relationship of a plurality of nodes included in the division target network TNW. As shown in FIG. 2, a plurality of nodes included in the division target network TNW are connected to a node outside the division target network TNW (external connection node) and connected to only the inside of the division target network TNW ( Internally connected nodes). In FIG. 2, external connection nodes are indicated by black circles, and internal connection nodes are indicated by white circles. The network dividing device 1 is directly or indirectly connected to at least one external node in the division target network TNW (if the network dividing device 1 is in the division target network TNW, it may be connected to an internal connection node). The communication status of each node in the division target network TNW can be received. The network dividing device 1 divides the division target network TNW based on the received communication status of each node.

  FIG. 3 is a configuration diagram illustrating an example of a functional configuration of the network dividing device 1. The network dividing device 1 includes a communication unit 10, an information acquisition unit 20, an attribute determination unit 30, a distribution processing unit 40, a division instruction unit 50, and a storage unit 60.

  The communication unit 10 includes hardware such as a network card, for example. The communication unit 10 communicates with each communication node in the network NW according to instructions from the information acquisition unit 20 and the division instruction unit 50.

  The information acquisition unit 20, the attribute determination unit 30, the distribution processing unit 40, and the division instruction unit 50 are software function units that function when, for example, a CPU (Central Processing Unit) (not shown) executes a program stored in the storage unit 60. It is. The storage unit 60 is, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), a flash memory, or the like. Not limited to this, some or all of these functional units may be realized by hardware such as an IC (Integrated Circuit) or an LSI (Large Scale Integration). Each functional unit does not need to be described by an independent program, and may be a relationship called by another functional unit as a subroutine, for example.

  The information acquisition unit 20 controls the communication unit 10 on a regular basis, for example, acquires information on the flow management information amount of each node included in the division target network TNW and the connection relationship of each node, and stores the information in the storage unit 60. .

  The flow management information amount is, for example, the number of times each node transmits and receives data (the total number of incoming links and outgoing links). The flow management information amount is not limited to the “number of times” in which the data size is not considered, and may be a value obtained by multiplying the data size by the number of times, for example. In addition, the information related to the connection relationship is, for example, information (connection partner list) indicating to which other node each node is directly connected. FIG. 4 is a diagram illustrating an example of information including information regarding the amount of flow management information and connection relationships acquired from each node. In FIG. 4, the node identification information is represented as “node No.”, but actually, an IP (Internet Protocol) address, a MAC (Media Access Control) address, or the like may be used.

  The attribute determination unit 30 analyzes the information illustrated in FIG. 4 to determine whether each node is an external connection node or an internal connection node, and uses the determination result as an attribute of the connection relationship of each node. The data is stored in the storage unit 60. FIG. 5 is a diagram illustrating an example of information to which a connection relation attribute is given by the attribute determination unit 30.

  Based on the information (FIG. 5) of each node stored in the storage unit 60, the distribution processing unit 40 causes each node to belong to one of the partial networks PNW1 and PNW2, thereby causing the division target network TNW to belong to the partial network PNW1. And PNW2. The distribution processing unit 40 distributes the communication load between the partial network PNW1 and the partial network PNW2 so that the communication load is equalized and the attribute of the connection relationship with other nodes is unevenly distributed. More specifically, the distribution processing unit 40 distributes the total value of the flow management information amount in the partial network PNW1 and the total value of the flow management information amount in the partial network PNW2 so as to balance the partial network PNW1. The communication load is equalized between the partial networks PNW2. Further, the distribution processing unit 40 preferentially selects external connection nodes for the partial network PNW1, and preferentially selects internal connection nodes for the partial network PNW2, so that the partial network PNW1 and the partial network PNW2 are selected. Make the connection-related attributes unevenly distributed.

  As a result, it is possible to equalize the communication load between the divided partial networks and to make the connection relation attributes unevenly distributed. That is, an uneven distribution relationship is generated in which a large amount of communication with the outside of the original division target network TNW is performed in the partial network PNW1, and a large amount of communication with the inside of the original division target network TNW is performed in the partial network PNW2. Can do. When such an uneven distribution relationship occurs, for example, when each node refers to the priority set for data when transferring data (packets), the number of priority levels in the partial network is reduced. can do. In the partial network PNW1, priority given to communication with the outside of the division target network TNW is mainly handled, and in the partial network PNW2, priority given to communication with the inside of the division target network TNW is mainly handled. This is because, in each partial network, it is not necessary to set priority and do not need to be handled. Here, there may be internal connection nodes in the partial network PNW1, but since the number (ratio) thereof decreases, for example, it is possible to handle them collectively such as “priority related to internal connections”. It becomes. The same applies to the external connection nodes in the partial network PNW2. As a result, communication control of each node can be simplified.

  The division instruction unit 50 transmits, for example, a network connection change instruction to each node in the division target network TNW so that the result of the division performed by the distribution processing unit 40 is reflected. Note that the network partitioning is not limited to being performed online as described above. For example, a new router or the like is installed in the partition target network TNW (for example, between the partial network PNW1 and the partial network PNW2). It may include offline work such as changing the IP address. In this case, the division instruction unit 50 instructs the content of the offline work to the worker by displaying the division result on a display device (not shown).

[Distribution processing]
Hereinafter, specific contents of the distribution process executed by the distribution processing unit 40 according to the first embodiment will be described. FIG. 6 is an example of a flowchart showing a flow of distribution processing executed by the distribution processing unit 40 according to the first embodiment. The process of the flowchart in FIG. 6 is started when, for example, the total amount of flow management information in the division target network TNW exceeds a predetermined upper limit value.

  First, the distribution processing unit 40 determines the central node of each partial network (step S100). The distribution processing unit 40 causes one of the external connection nodes to belong to the partial network PNW1 and one of the internal connection nodes to the partial network PNW2 as a central node. It is desirable that the minimum number of hops between two nodes determined as these central nodes be as large as possible.

  Next, the distribution processing unit 40 determines that the total value (first total value) of the flow management information amounts of the nodes that have already been determined to belong to the partial network PNW1 at that time point already belongs to the partial network PNW2. Is smaller than the total value (second total value) of the flow management information amount of the determined node (step S102). When step S102 is executed for the first time, the first total value is the flow management information amount of the central node of the partial network PNW1, and the second total value is the flow management information amount of the central node of the partial network PNW2. is there.

  When the distribution processing unit 40 determines that the first total value is smaller than the second total value, that is, the communication load in the partial network PNW1 is smaller than the communication load in the partial network PNW2, the distribution processing unit 40 performs the following processing. The distribution processing unit 40 selects one external connection node from among the nodes adjacent to the node in the division target network TNW that has already been determined to belong to the partial network PNW1, and assigns it to the partial network PNW1. Be affiliated (step S104). Here, the adjacent node is a node connected to a certain node by one hop.

  In the following description, when “select one node” or the like is described, any method can be adopted as the selection method, unless the selection method is specified. For example, the distribution processing unit 40 may select at random from the corresponding nodes, or may select in the order of the identification numbers given to the nodes.

  Next, the distribution processing unit 40 determines whether or not the corresponding node exists in step S104 (step S106). If there is a corresponding node, the distribution processing unit 40 proceeds to step S116. When the corresponding node does not exist, the distribution processing unit 40 is an internal connection node among the nodes adjacent to the node in the division target network TNW that has already been determined to belong to the partial network PNW1. Is selected to belong to the partial network PNW1 (step S108). Then, the distribution processing unit 40 proceeds to step S116.

  On the other hand, when it is determined that the first total value is larger than the second total value, that is, the communication load in the partial network PNW1 is larger than the communication load in the partial network PNW2, the distribution processing unit 40 performs the following processing. . The distribution processing unit 40 selects one internal connection node from among the nodes adjacent to the node in the division target network TNW that has already been determined to belong to the partial network PNW2, and assigns it to the partial network PNW2. Be affiliated (step S110).

  Next, the distribution processing unit 40 determines whether or not the corresponding node exists in step S110 (step S112). If there is a corresponding node, the distribution processing unit 40 proceeds to step S116. When the corresponding node does not exist, the distribution processing unit 40 is a node in the division target network TNW, and is an external connection node among the adjacent nodes of the node that has already been determined to belong to the partial network PNW2. Is selected to belong to the partial network PNW2 (step S114). Then, the distribution processing unit 40 proceeds to step S116.

  In step S116, the distribution processing unit 40 determines whether or not the processing in steps S104 to S108 or steps S110 to S114 has been executed for all nodes. The distribution processing unit 40 returns to step S102 when the processing is not executed for all the nodes, and ends the processing of the flowchart of FIG. 6 when the processing is executed for all the nodes.

  In step S102, if the first total value and the second total value are equal, the processing in steps S104 to S108 may be performed, or conversely, the processing in steps S110 to S114 may be performed. Randomly, either the processing of steps S104 to S108 or the processing of steps S110 to S114 may be performed.

[Summary]
According to the network dividing apparatus 1 of the first embodiment described above, it is possible to equalize the communication load between the divided partial networks and to make the connection relation attributes unevenly distributed. As a result, for example, when the priority set for the data is referred to when each node transfers the data, the number of priority levels in the partial network can be reduced. Thereby, communication control of each node can be simplified.

Second Embodiment
Hereinafter, the network dividing device 2 of the second embodiment will be described. In the second embodiment, the overall image of the network, the connection relationship of a plurality of nodes included in the division target network TNW, and the functional configuration of the network dividing apparatus are the same as those in the first embodiment. They will be used, and explanations of each will be omitted.

  Compared with the first embodiment, the distribution processing unit 40 according to the second embodiment performs a process that places more importance on uneven distribution of attributes of node connection relations than equalizing communication loads. More specifically, when the flow management information amount of the partial network PNW1 is smaller than the management information of the partial network PNW2, even if the external connection node cannot be added to the partial network PNW1, the difference in the flow management information amount is the threshold value. If it is below, an internal connection node is added to the partial network PNW2. On the contrary, when the flow management information amount of the partial network PNW1 is larger than the management information of the partial network PNW2, the difference in the flow management information amount is equal to or less than the threshold even when the internal connection node cannot be added to the partial network PNW2. If there is, an external connection node is added to the partial network PNW1.

[Distribution processing]
FIG. 7 is an example of a flowchart showing the flow of distribution processing executed by the distribution processing unit 40 according to the second embodiment. The process of the flowchart of FIG. 7 is started when, for example, the total amount of flow management information in the division target network TNW exceeds a predetermined upper limit value.

  First, as in the first embodiment, the distribution processing unit 40 determines the central node of each partial network (step S200), and the flow of nodes that have already been determined to belong to the partial network PNW1 at that time It is determined whether or not the total value (first total value) of the management information amount is smaller than the total value (second total value) of the flow management information amount of the nodes that have already been determined to belong to the partial network PNW2. (Step S202).

  When the distribution processing unit 40 determines that the first total value is smaller than the second total value, that is, the communication load in the partial network PNW1 is smaller than the communication load in the partial network PNW2, the distribution processing unit 40 performs the following processing. The distribution processing unit 40 selects one external connection node from among the nodes adjacent to the node in the division target network TNW that has already been determined to belong to the partial network PNW1, and assigns it to the partial network PNW1. Be affiliated (step S204).

  Next, the distribution processing unit 40 determines whether or not the corresponding node exists in step S204 (step S206). When the corresponding node exists, the distribution processing unit 40 proceeds to step S228. When the corresponding node does not exist, the distribution processing unit 40 determines whether or not a difference obtained by subtracting the first total value from the second total value is equal to or less than a threshold value (step S208).

  When the difference is equal to or smaller than the threshold value, the distribution processing unit 40 selects one internal connection node from among the nodes adjacent to the node in the division target network TNW that has already been determined to belong to the partial network PNW2. Are selected and belong to the partial network PNW2 (step S210). Then, the distribution processing unit 40 determines whether or not the corresponding node exists in step S210 (step S212). When the corresponding node exists, the distribution processing unit 40 proceeds to step S228.

  If it is determined in step S208 that the difference exceeds the threshold value, or if it is determined in step S212 that the corresponding node does not exist, the distribution processing unit 40 is a node in the division target network TNW, and has already been subnetworked. One internal connection node is selected from the adjacent nodes of the node determined to belong to PNW1, and is assigned to partial network PNW1 (step S214). Then, the distribution processing unit 40 proceeds to step S228.

  On the other hand, when it is determined that the first total value is larger than the second total value, that is, the communication load in the partial network PNW1 is larger than the communication load in the partial network PNW2, the distribution processing unit 40 performs the following processing. . The distribution processing unit 40 selects one internal connection node from among the nodes adjacent to the node in the division target network TNW that has already been determined to belong to the partial network PNW2, and assigns it to the partial network PNW2. Be assigned (step S216).

  Next, the distribution processing unit 40 determines whether or not the corresponding node exists in step S216 (step S218). When the corresponding node exists, the distribution processing unit 40 proceeds to step S228. When the corresponding node does not exist, the distribution processing unit 40 determines whether or not a difference obtained by subtracting the second total value from the first total value is equal to or less than a threshold value (Step S220).

  When the difference is equal to or smaller than the threshold value, the distribution processing unit 40 selects one external connection node from among the adjacent nodes of the nodes in the division target network TNW that have already been determined to belong to the partial network PNW1. Are selected and belong to the partial network PNW1 (step S222). Then, the distribution processing unit 40 determines whether or not the corresponding node exists in step S222 (step S224). When the corresponding node exists, the distribution processing unit 40 proceeds to step S228.

  If it is determined in step S220 that the difference exceeds the threshold value, or if it is determined in step S224 that the corresponding node does not exist, the distribution processing unit 40 is a node in the division target network TNW and is already a partial network. One external connection node is selected from the adjacent nodes of the node determined to belong to PNW2, and is assigned to the partial network PNW2 (step S226). Then, the distribution processing unit 40 proceeds to step S228.

  In step S228, the distribution processing unit 40 determines whether or not the processing of steps S204 to S214 or steps S216 to S226 has been executed for all nodes. The distribution processing unit 40 returns to step S202 when the process is not executed for all nodes, and ends the process of the flowchart of FIG. 7 when the process is executed for all nodes.

  In step S202, if the first total value and the second total value are equal, the processing in steps S204 to S214 may be performed, or conversely, the processing in steps S216 to S226 may be performed. Randomly, either the processing of steps S204 to S214 or the processing of steps S216 to S226 may be performed.

[Summary]
According to the network dividing device 2 of the second embodiment described above, similarly to the first embodiment, it is possible to equalize the communication load between the divided partial networks and to make the attribute of the node connection relation unevenly distributed. it can. As a result, for example, when the priority set for the data is referred to when each node transfers the data, the number of priority levels in the partial network can be reduced. Thereby, communication control of each node can be simplified.

  In addition, according to the network dividing device 2 of the second embodiment, compared to the first embodiment, it is possible to perform a process that places more importance on uneven distribution of attributes of node connection relations.

<Third Embodiment>
Hereinafter, the network dividing device 3 of the third embodiment will be described. In the third embodiment, the overall image of the network, the connection relationship of a plurality of nodes included in the division target network TNW, and the functional configuration of the network dividing apparatus are the same as those in the first embodiment. They will be used, and explanations of each will be omitted.

  Compared with the first embodiment and the second embodiment, the distribution processing unit 40 according to the third embodiment is configured to make the connection structure of the network NW including the division target network TNW after the division close to a tree structure. Perform more important processing. More specifically, the distribution processing unit 40 assigns an external connection node to an external connection node according to a priority order based on a connection relationship with an external node of the division target network TNW when the external connection node belongs to any partial network. Select.

  Here, a root network and a parent network of a network that is not a root network are defined. A network that is not divided at all is a root network, and when a root network that is not divided at all is divided, one of the partial networks is set as a new root network. Thereafter, when the root network is divided, a partial network having a central node connected to the external network becomes a new root network. A parent network of a network that is not a root network is defined as an adjacent network through which the shortest path from the corresponding network to the root network passes. All adjacent networks other than the parent network are child networks.

[Distribution processing]
FIG. 8 is an example of a flowchart showing the flow of distribution processing executed by the distribution processing unit 40 according to the third embodiment. The process of the flowchart in FIG. 8 is started when, for example, the total amount of flow management information in the division target network TNW exceeds a predetermined upper limit value.

  First, the distribution processing unit 40 determines the central node of each partial network (step S300). The distribution processing unit 40 causes one of the external connection nodes to belong to the partial network PNW1 and one of the internal connection nodes to the partial network PNW2 as a central node. It is desirable that the minimum number of hops between two nodes determined as these central nodes be as large as possible.

  The distribution processing unit 40 according to the third embodiment uses an external connection node connected to the parent network as the central node of the partial network PNW1 if the target network TNW is not the root network, and the target network TNW as the root network. Each external connection node connected to the child network is selected.

  Next, the distribution processing unit 40 determines that the total value (first total value) of the flow management information amounts of the nodes that have already been determined to belong to the partial network PNW1 at that time point already belongs to the partial network PNW2. Is smaller than the total value (second total value) of the flow management information amount of the determined node (step S302).

  When the distribution processing unit 40 determines that the first total value is smaller than the second total value, that is, the communication load in the partial network PNW1 is smaller than the communication load in the partial network PNW2, the distribution processing unit 40 performs the following processing. The distribution processing unit 40 selects one external connection node in accordance with a predetermined priority from the nodes adjacent to the node in the division target network TNW that has already been determined to belong to the partial network PNW1. And belong to the partial network PNW1 (step S304). A procedure for selecting an external connection node in accordance with a predetermined priority will be described later with reference to FIG.

  Next, the distribution processing unit 40 determines whether or not the corresponding node exists in step S304 (step S306). If there is a corresponding node, the distribution processing unit 40 proceeds to step S316. When the corresponding node does not exist, the distribution processing unit 40 is an internal connection node among the nodes adjacent to the node in the division target network TNW that has already been determined to belong to the partial network PNW1. Is selected to belong to the partial network PNW1 (step S308). Then, the distribution processing unit 40 proceeds to step S316.

  On the other hand, when it is determined that the first total value is larger than the second total value, that is, the communication load in the partial network PNW1 is larger than the communication load in the partial network PNW2, the distribution processing unit 40 performs the following processing. . The distribution processing unit 40 selects one internal connection node from among the nodes adjacent to the node in the division target network TNW that has already been determined to belong to the partial network PNW2, and assigns it to the partial network PNW2. Be affiliated (step S310).

  Next, the distribution processing unit 40 determines whether or not the corresponding node exists in step S310 (step S312). If there is a corresponding node, the distribution processing unit 40 proceeds to step S316. If the corresponding node does not exist, the distribution processing unit 40 has a predetermined priority among the nodes adjacent to the node in the division target network TNW that has already been determined to belong to the partial network PNW2. One external connection node is selected according to the rank, and it belongs to the partial network PNW2 (step S314). A procedure for selecting an external connection node in accordance with a predetermined priority will be described later with reference to FIG. Then, the distribution processing unit 40 proceeds to step S316.

  In step S316, the distribution processing unit 40 determines whether or not the processing in steps S304 to S308 or steps S310 to S314 has been executed for all nodes. The distribution processing unit 40 returns to step S302 when the processing is not executed for all the nodes, and ends the processing of the flowchart of FIG. 8 when the processing is executed for all the nodes.

  In step S302, when the first total value and the second total value are equal, the processing in steps S304 to S308 may be performed, or conversely, the processing in steps S310 to S314 may be performed. Any one of the processes in steps S304 to S308 and the processes in steps S310 to S314 may be performed at random. In the third embodiment, processing similar to that in the second embodiment may be incorporated.

  FIG. 9 is an example of a flowchart showing the flow of processing when selecting an external connection node in step S304. 9 and 10, the network is abbreviated as “NW”.

  First, the distribution processing unit 40 determines whether or not the own network, that is, the division target network TNW is a root network (step S400). When the own network is not the root network, the distribution processing unit 40 determines whether or not there is an external connection node (and an adjacent node) connected to a node in the parent network for the own network (step S402). When there is an external connection node connected to a node in the parent network, the distribution processing unit 40 selects an external connection node connected to the node in the parent network (step S404).

  When the own network is a root network, or when there is no external connection node connected to a node in the parent network, the distribution processing unit 40 is connected to a node in the child network already connected to the partial network PNW1. It is determined whether or not there is a connection node (step S406). When there is an external connection node connected to a node in the child network that is already connected to the partial network PNW1, the distribution processing unit 40 selects the external connection node (step S408).

  When there is no external connection node connected to the node in the child network already connected to the partial network PNW1, the distribution processing unit 40 connects to both the partial networks PNW1 and PNW2 and the node in the unconnected child network. It is determined whether or not an external connection node exists (step S410). When there is an external connection node connected to both of the partial networks PNW1 and PNW2 and a node in the unconnected child network, the distribution processing unit 40 selects the external connection node (step S412).

  When there is no external connection node connected to both the partial networks PNW1 and PNW2 and a node in the unconnected child network, the distribution processing unit 40 connects to a node in the child network already connected to the partial network PNW2. An external connection node is selected (step S414).

  With this processing, the external connection node belonging to the partial network PNW1 is connected to the parent network → the partial network PNW1 and the already connected child network → the child network not connected to any partial network → the other partial network PNW2 and the already connected child. Selected in network priority order.

  FIG. 10 is an example of a flowchart showing the flow of processing when selecting an external connection node in step S314.

  First, the distribution processing unit 40 determines whether there is an external connection node connected to a node in the child network that is already connected to the partial network PNW2 (step S500). If there is an external connection node connected to a node in the child network that is already connected to the partial network PNW2, the distribution processing unit 40 selects the external connection node (step S502).

  When there is no external connection node connected to a node in the child network already connected to the partial network PNW2, the distribution processing unit 40 connects to both the partial networks PNW1 and PNW2 and a node in the unconnected child network. It is determined whether or not an external connection node exists (step S504). When there is an external connection node connected to both the partial networks PNW1 and PNW2 and a node in the unconnected child network, the distribution processing unit 40 selects the external connection node (step S506).

  When there is no external connection node connected to both partial networks PNW1 and PNW2 and a node in the unconnected child network, the distribution processing unit 40 connects to a node in the child network already connected to the partial network PNW1. It is determined whether or not an external connection node exists (step S508). When there is an external connection node connected to a node in the child network already connected to the partial network PNW1, the distribution processing unit 40 selects the external connection node (step S510).

  When there is no external connection node connected to the node in the child network already connected to the partial network PNW1, the distribution processing unit 40 selects the external connection node connected to the node in the parent network (step S512).

  By this processing, the external connection node belonging to the partial network PNW2 is opposite to the partial network PNW1, and the partial network PNW2 and the already connected child network → the child network not connected to any partial network → the other partial network PNW1 And the connected child network → the parent network are selected in order of priority.

  As a result, the parent network is preferentially connected to the partial network PNW1, and the group connected to the partial network PNW1 and the group connected to the partial network PNW2 of the child networks tend to be separated. As a result, the connection topology between the partial networks after the network division can be made close to a tree structure, and network division can be realized in which the future non-uniformity of the number of passing flows in the two partial networks is increased.

[Summary]
According to the network dividing device 3 of the third embodiment described above, as in the first embodiment, it is possible to equalize the communication load between the divided partial networks and to make the attribute of the node connection relation unevenly distributed. it can. As a result, for example, when the priority set for the data is referred to when each node transfers the data, the number of priority levels in the partial network can be reduced. Thereby, communication control of each node can be simplified.

  Further, according to the network dividing device 3 of the third embodiment, when an external connection node belongs to one of the partial networks, it belongs according to a priority order based on a connection relationship with a node outside the division target network TNW. Since the external connection node is selected, the connection structure of the network NW including the division target network TNW after the division can be made close to a tree structure.

<About link deletion>
When the target network TNW is divided according to each of the above embodiments, as a result, it may be possible to delete a link in the network NW. FIG. 11 is a diagram exemplifying a link that can be deleted in the divided network NW. As described above, the partial network PNW2 may include not only an internal connection node but also an external connection node connected to a parent network or a child network. Among such external connection nodes, the external connection link may be deleted for nodes connected to the nodes in the partial network PNW1 and the already connected parent network or child network. By removing external connection links in this way, the closed circuit composed of multiple partial networks is removed, and the connection topology between the partial networks is accurately made into a tree structure. Is maximized.

  The link deletion may be performed by each node according to an instruction signal transmitted from the network dividing device, or the deletion target link may be manually deleted.

  As mentioned above, although the form for implementing this invention was demonstrated using embodiment, this invention is not limited to such embodiment at all, In the range which does not deviate from the summary of this invention, various deformation | transformation and substitution Can be added.

  For example, in each embodiment, the node having the maximum number of flows with the external network is selected as the central node of the partial network PNW1, and at each stage, the partial network PNW1 is connected to the external network among the external connection nodes. When the adjacent node having the maximum number of flows is selected and it is necessary to select the external connection node in the partial network PNW2, select the adjacent node having the minimum number of flows with the external network. Also good. In this way, communication with the external network can be further unevenly distributed in the partial network PNW1.

DESCRIPTION OF SYMBOLS 1 Network division | segmentation apparatus 10 Communication part 20 Information acquisition part 30 Attribute discrimination | determination part 40 Distribution processing part 50 Division | segmentation instruction | indication part 60 Memory | storage part NW network TNW Division | segmentation object network PNW1, PNW2 Partial network

Claims (11)

A network dividing device for dividing a division target network including a plurality of nodes into a first partial network and a second partial network,
An index value indicating the communication load of each of the plurality of nodes, an acquisition unit for acquiring information related to a connection relationship;
Communication load is equalized between the first partial network and the second partial network, and an external connection node connected to a node outside the division target network and a node outside the division target network are not connected. A distribution unit that distributes the plurality of nodes to the first partial network or the second partial network so that internal connection nodes are unevenly distributed;
A network dividing device comprising: The network partitioning device according to claim 1,
The distribution unit preferentially selects the external connection node for the first partial network and preferentially selects the internal connection node for the second partial network. Making the internal connection nodes unevenly distributed;
Network partition device. The network dividing device according to claim 1 or 2,
The distribution unit balances a total value (first total value) of the index values in the first partial network and a total value (second total value) of the index values in the second partial network. Allocating the plurality of nodes to the first partial network or the second partial network to equalize a communication load between the first partial network and the second partial network;
Network partition device. The network partitioning device according to claim 3, wherein
The distribution unit is
When the first total value is smaller than the second total value, if the external connection node satisfying a first predetermined condition exists among unallocated nodes, the existing external connection node is set as the first total value. Distributing to the partial network, and if not present, allocating unallocated internal connection nodes satisfying the first predetermined condition to the first partial network;
When the first total value is larger than the second total value, if the internal connection node satisfying a second predetermined condition exists among unallocated nodes, the existing internal connection node is set to the second value. Allocating to the partial network, and if not present, allocating unallocated external connection nodes satisfying the second predetermined condition to the second partial network;
Network partition device. The network partitioning device according to claim 4, wherein
The first predetermined condition is that it is a node adjacent to a node that has already been allocated to the first partial network;
The second predetermined condition is that it is an adjacent node of a node that has already been allocated to the second partial network.
Network partition device. The network dividing device according to claim 4 or 5, wherein
The distribution unit is
Even if the first total value is smaller than the second total value and the external connection node that satisfies the first predetermined condition does not exist among unallocated nodes, the second total value If the difference obtained by subtracting the first total value from the threshold is less than or equal to the threshold value, the unallocated internal connection nodes satisfying the second predetermined condition are allocated to the second partial network,
Even if the first total value is larger than the second total value and the internal connection node that satisfies the second predetermined condition does not exist among unallocated nodes, the first total value If the difference obtained by subtracting the second total value from the threshold is less than or equal to the threshold value, the unallocated external connection nodes satisfying the first predetermined condition are allocated to the first partial network.
Network partition device. The network dividing device according to any one of claims 1 to 6,
When distributing the external connection node to the first partial network, the distribution unit preferentially distributes a node having a large communication load related to communication with a node outside the division target network; When allocating the external connection node to the partial network, the node having a small communication load related to communication with the node outside the division target network is preferentially allocated.
Network partition device. The network dividing device according to any one of claims 1 to 7,
When the distribution unit distributes the external connection node to the first partial network, the distribution unit selects the external connection node according to a first rule based on a connection relationship with a node outside the division target network, and When allocating the external connection node to the second partial network, the external connection node is selected according to a second rule having a tendency opposite to the first rule.
Network partition device. The network dividing device according to any one of claims 1 to 8,
Of the external connection nodes allocated to the second partial network, those that communicate with a network outside the division target network communicated by the external connection node allocated to the first partial network Send a signal to remove links to networks outside of the network,
Network partition device. A network dividing method for dividing a division target network including a plurality of nodes into a first partial network and a second partial network,
Obtaining an index value indicating a communication load of each of the plurality of nodes, and information on a connection relationship;
Communication load is equalized between the first partial network and the second partial network, and an external connection node connected to a node outside the division target network and a node outside the division target network are not connected. Distributing the plurality of nodes to the first partial network or the second partial network so that internal connection nodes are unevenly distributed;
Network partitioning method. A network division program for causing a computer to divide a division target network including a plurality of nodes into a first partial network and a second partial network,
In the computer,
Obtaining an index value indicating the communication load of each of the plurality of nodes and information related to a connection relationship;
Communication load is equalized between the first partial network and the second partial network, and an external connection node connected to a node outside the division target network and a node outside the division target network are not connected. Distributing the plurality of nodes to the first partial network or the second partial network so that internal connection nodes are unevenly distributed;
Network partition program.

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