JP2978648B2 - Optimal route determination method for network system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining an optimum route in a network system in which a plurality of computers are connected to each other via a communication line.

[0002]

2. Description of the Related Art In the case of a communication mode in which a plurality of computer systems are interconnected in a network, information for selecting a communication line for communication between computers (nodes) is required. More specifically, these pieces of information include an outgoing line number from the transmitting node to the other node of the receiving destination, an optimum route number that gives the shortest route on the network, and the like. FIG. 2 is a diagram illustrating an example of a network system. In the network system as shown in FIG. 2, when communication between nodes is performed, communication is performed using a route number defined in the network. That is, as shown in FIG. 2, in the communication network, a route for communication from the node N1 to the nodes N2, N4 and N3, and a route from the node N1 to the nodes N2 and N2.
3. A route for communicating with the node N4 and a route for communicating from the node N3 to the nodes N2 and N4 are conceivable.
These routes are called routes.

In the case of a network configuration as shown in FIG. 2, for example, for communication from the node N4 to the partner node N1, the route R1 is the optimum route and the route R2 is the backup route. The outgoing lines are L1 and L2. Thus, when a failure occurs between the nodes N2 and N4 on the optimal route R1, it is possible to communicate using the backup route R2. Conventionally, such route information and information for determining an outgoing line to a partner node have been set by a system administrator for each node by system generation or the like. These setting information are information set in the table shown in FIG.

[0004]

However, the above-mentioned prior art has the following problems. That is, the optimal route number, outgoing line number, and spare route number corresponding to each node are set by the system generation or the like. However, since these information are different for each node, it is necessary to manage the information for each node. . For this reason, there has been a problem that the burden of information setting work on the system administrator is large, and when the network is complicated, there is a possibility that information setting error or the like may occur. The present invention has been made by paying attention to the above points. By automatically generating information such as an optimum route and a spare route to be managed for each node and an outgoing line to them from a small amount of information, It is an object of the present invention to provide a method of determining an optimal route of a network system, which simplifies the management information of the network system and facilitates the information setting operation.

[0005]

According to the present invention, there is provided a method for determining an optimum route in a network system, the method comprising the steps of: performing a communication between nodes of a network including a plurality of nodes and a communication line connecting the nodes; All nodes that provide a plurality of routes from one node of the plurality of nodes to another node via a relay node on the network on the network when determining whether to pass through a node and a communication line. A common route table is prepared, and the own node number for identifying the own node, the adjacent node number for identifying the adjacent node adjacent to the own node, and the outgoing line connecting the own node to each adjacent node are identified. An outgoing line number is provided, and a node information table unique to each node is prepared. For each route given in the route table, the node The number of relay nodes on the way from the own node given to the communication table to the other node of each communication partner following the respective route is counted, and the route with the minimum number of nodes or the node with the minimum number of relay nodes is counted. When there are a plurality of routes, one of the routes is determined as the optimal route, and the outgoing line number to the adjacent node toward each other node on the optimal route is extracted from the node information table and the route is determined. A spare route for storing the route other than the route determined as the optimal route, storing the route other than the route determined as the optimal route, in order from the smaller number of intermediate relay nodes in order to deal with the failure of the optimal route. And extracting the outgoing line number to the adjacent node toward each other node on each of the backup routes from the node information table and storing the outgoing line number corresponding to each of the backup routes.

[0006]

The optimum route determination of the network system according to the present invention.
In the method , in addition to the route table prepared in advance, a node information table storing the outgoing line from the own node, the number of the adjacent node connected thereto and the number of the own node is prepared, and communication can be performed. Automatically generate necessary information. This generation process is as follows. First, for each route stored in the route table, a return route is added to a forward route from a certain node to another node of a communication partner to generate a round trip route. Then, these round trip routes are stored in the route configuration table. Next, the own node is extracted from the node information table, and the own node number on one round trip route in the route configuration table is searched. When the own node is found, the number of nodes from there is counted, and the number of nodes when another node is found is stored. If the own node is found again during the counting, the number of nodes is reset and the number of nodes from that point until another node is found is counted. The outgoing line number to the next node of the own node is extracted from the node information table and stored. These counts are made for all round trips. The route with the smallest number of nodes is set as the optimal route, and the second and subsequent routes are set as the spare routes. The above-described determination of the optimum route and the backup route is performed for all the other nodes of the communication partner, and the results are stored in the route management table.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of an embodiment of a network system to which the method of the present invention is applied. In the illustrated system, nodes N1, N2, N3, and N4 exist. The nodes N2, N3, and N4 are connected to each other by three physical lines. And node N
1 and N2 are connected by one physical line.
As a result, in the communication network, the routes R1, R
2. There are three routes, R3. The route R1 is a route for communication from the node N1 to the nodes N2, N4, and N3. The route R2 runs from the node N1 to the node N
2, a route for communication to the nodes N3 and N4.
The route R3 is a route for communicating from the node N3 to the nodes N2 and N4.

[0008] Of these routes, each node is provided with a route table T1 and a node information table T2 to determine the optimum route number and outgoing line number for communication between the nodes (for the node N4). Only shown). FIG.
FIG. 4 is an explanatory diagram of a configuration of a route table. The route table is provided as information common to all nodes. In this route table, the route numbers R1, R2, R
h and the number of the node existing on the outward route of each route are stored. FIG. 4 is an explanatory diagram of the configuration of the node information table. As shown in the figure, the node information table includes an own node number nc given to each node defined by the system administrator, an adjacent node number nb adjacent to the own node,
nd, etc. and their corresponding line numbers L1, L2, etc. are stored.

FIG. 5 is an explanatory diagram of the configuration of the route configuration table. This route configuration table is a table that is set in the process of obtaining an optimum route and the like in the present invention. The route configuration table sets a node number of a node existing on a reciprocating route of each route from the route information defined in the route table. For example, for the route R1, na, nb, nc, nd, n
Set c, nb, na. FIG. 6 is an explanatory diagram of the configuration of the node count table. This node count table is also set in the process of obtaining the optimum route and the like in the present invention. The node count table sets, for each communication partner, the number of relay nodes from the own node in each route to another node of the communication partner. When communication is performed from the own node to a certain node, a node number (outgoing node number) of an adjacent node that directly communicates with the own node on each route is also set.
Here, the other node of the communication partner is all nodes other than the own node existing under the network.

FIG. 7 is an explanatory diagram of the configuration of the route management table. This route management table is a table for setting an optimum route number and an outgoing line number, and a spare route number and an outgoing line number for each other node of each communication partner automatically generated in the present invention. Next, a procedure for determining an optimal route according to the present invention will be described. FIG. 8 is a flowchart illustrating an optimal route determination processing procedure according to the method of the present invention, and FIG. 9 is a diagram illustrating a setting example of each table generated from the network example of FIG. FIG. 10 is an explanatory diagram of a search procedure of the route configuration table. As a precondition of the present invention, a route table and a node information table need to be provided to the communication system of each node.

First, a node number existing on a reciprocating route of each route is set in the route configuration table (step S1).
Here, the arrangement of the node numbers on the return route of the route is in the reverse order to the arrangement of the forward route. Therefore, the node numbers existing on the outward route of the route from the route table are arranged in order from the head node number in the route configuration table. After arranging the node numbers for the outbound route, except for the last node number of the outbound route,
The node numbers are arranged in reverse order to the outward route. In this way, for each route, the node number existing on the outward route is set in the route configuration table. When the route table of FIG. 9A is defined from the network example of FIG.
As shown in the route configuration table of FIG. 3B, a node number existing on the round trip route is set for each route. Next, the node count table is set. First, the own node number is obtained from the node information table (step S
2). When the node information table of FIG. 9C is given, the own node number is “4”.

Then, for each communication partner node, the number of relay nodes and the outgoing line number existing between the own node and the communication partner node on each route are obtained and set in the node count table. Here, a method of setting the node count table will be described with reference to FIG. First, FIG. 9 (c)
The own node number “4” is obtained from the node information table of “1”. Next, regarding the communication partner node number “1”, FIG.
The route configuration table of (b) is searched, and the route number “1” is searched.
The route is determined to be the optimum route in ascending order of the number of relay nodes existing between the own node and the communication partner node on the route, and extracted for each node (step S3). In this case, a point where the number of the own node and the number of the partner node are small is detected from the route configuration table. That is, as shown in FIG. 10, on the route with the route number “1”, it is detected that the third node number from the top node is set to the own node number “4”, but the fifth node Since the own node number “4” is detected again as the number, the number of relay nodes “1” from here to the partner node number “1”
Is counted and set in the node count table. The above processing is performed for the other routes R2 and R3. Then, the route with the smallest number of relay nodes is set as the optimal route, and the spare routes are set in ascending order of the number of relay nodes. However, when the number of relay nodes is the same, the one with the smaller route number has priority.

Next, the next node of the own node is set as an adjacent node, and the outgoing line number of the corresponding node is extracted from the node information table and set as an outgoing line (step S4). For example, as shown in FIG. 10, for the route number “1”,
The adjacent node number corresponding to the own node number “4” is “2”, and the outgoing line number obtained from the node information table is “1” correspondingly. Finally, FIG. 9 (c),
The optimum route number and the outgoing line number and the spare route number and the outgoing line number obtained from the node information table and the node count table shown in (d) are set in the route management table for each communication partner node (step S5). ).

[0014]

As described above, according to the method for determining an optimum route of a network system of the present invention, communication information is generated from a route table common to the network system and a node information table having a minimum amount of information. With this configuration, it is possible to automatically and without error generate information such as an optimum route, a spare route, and an outgoing line that need to be managed for each node. In addition, when a network change occurs, it is possible to cope with it by changing only a portion of the information such as the route table, the own node number, and the adjacent node number that needs to be changed, which is smaller than a conventional one. Become.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a network system to which a method of the present invention is applied.

FIG. 2 is a block diagram of an example of a conventional network system.

FIG. 3 is an explanatory diagram of a configuration of a route table.

FIG. 4 is an explanatory diagram of a configuration of a node information table.

FIG. 5 is an explanatory diagram of a configuration of a route configuration table.

FIG. 6 is an explanatory diagram of a configuration of a node count table.

FIG. 7 is an explanatory diagram of a configuration of a route management table.

FIG. 8 is a flowchart illustrating an optimal route determination processing procedure according to the method of the present invention.

FIG. 9 is an explanatory diagram of a setting example of each table.

FIG. 10 is an explanatory diagram of a search procedure of a route configuration table.

[Explanation of symbols]

 N1 to N4 Node R1 to R3 Route T1 Route table T2 Node information table

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-61527 (JP, A) JP-A-2-170748 (JP, A) JP-A-3-6951 (JP, A) JP-A-4- 70036 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04L 12/00 H04L 12/56

Claims (1)

(57) [Claims] 1. A communication system comprising: a plurality of nodes; and a communication line connecting the nodes. When determining which node or communication line to pass through when communicating between the nodes, A route table common to all nodes, which provides a plurality of routes from one of the nodes to another node via a relay node on the network, is prepared. Prepare a node information table unique to each node, which gives a node number, an adjacent node number for identifying an adjacent node adjacent to the own node, and an outgoing line number for identifying an outgoing line connecting the own node and each adjacent node. For each route given in the route table, each communication route is traced from the own node given in the node information table. Count the number of relay nodes on the way to the other node of the hand, and if there is a route with the minimum number of nodes or a plurality of routes with the minimum number of nodes, select one of them as the optimal route. The route is determined and the outgoing line number to the adjacent node toward each other node on the optimal route is taken out from the node information table and stored in correspondence with the optimal route, and the optimal route is determined. The routes other than the route are sequentially determined as the spare routes for dealing with the failure of the optimal route in the order of the small number of intermediate nodes, and the adjacent nodes toward the other nodes on the respective spare routes are determined. Extracting an outgoing line number from the node information table and storing the outgoing line number corresponding to each of the backup routes .