JPH0998158A - Network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable high-efficiency backup by performing required connection between the regular router and subordinate router of a base system and a branch system through a backup line and switching the line according to the priority defined inside the routers. SOLUTION: The regular base router is connected with the regular branch router by a dedicated main line 1 and a backup line 2, and the subordinate base router, regular branch router and subordinate route are respectively connected by backup lines 3 and 4. Then, polling is periodically performed to the line 1 and when any fault is detected, the lines 2-4 are switched based on the priority defined inside the routers. Thus, high-efficiency backup configuration for securing maximum reliability with minimum resources can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to efficient backup means for constructing a backup configuration in a large scale network system.

[0002]

2. Description of the Related Art Conventionally, in the line switching method disclosed in Japanese Patent Application Laid-Open No. 2-60337, there is disclosed a technique for switching to a backup line using ISDN in the event of a line failure and preparing for a failure of a dedicated line. With this method, when the line switching device fails,
There was a risk that all operations of the base system and branch system would go down. Therefore, there has been a demand for a configuration in which the maximum reliability can be secured with the minimum required resources even when the line switching device fails.

[0003]

In the conventional network system, the configuration considering the line failure is mainly used.
In this case, in the event of a router failure, there is a risk that the entire net configuration will go down. In addition, when a router failure is taken into consideration, it is common to provide a sub-configuration that is the same as the main configuration to deal with it, which increases the cost for the sub-configuration and also imposes a load on the configuration maintenance. The problem arises that it can increase.

Therefore, it is an object of the present invention to provide a network system that realizes an efficient backup configuration that secures maximum reliability with necessary and minimum resources.

[0005]

[Means for Solving the Problems] In order to realize a backup configuration in which all failure patterns are taken into consideration, a primary router and a secondary router connected to a base system are changed from one-to-one backup configuration to multiple routers. A composite backup configuration of 1-to-n backup is provided.

In order to realize the switching method in the composite backup configuration, the router on the terminating side regularly monitors the connection state of the main route. When the failure of the main route is detected, the connection is established and switched based on the priority order of the backup route.

The composite backup is to configure a route from the router on the terminating side to a plurality of routers. The switching to the backup path is performed by the router on the terminating side periodically polling the main path and based on the priority order information defined by the communication control device when a failure is detected. In addition, exclusive control is performed by the router on the terminating side so that connection can be established for both the main route and the backup route.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a configuration showing an embodiment of the invention will be described with reference to FIG. Normally, communication is performed from the main router to the main router of the branch using the main line (dedicated line) 1. Next, a backup line 2 is provided from the site main router to the branch main router in case of main line failure. This line is ISDN
A public line such as can be used. In addition, in preparation for a failure of the primary router, the secondary router and backup line 3
Is provided. Then, in preparation for a branch primary router failure, a backup line 4 is provided from the branch secondary router to the branch secondary router. This line can also use a public line such as ISDN. As mentioned above, by securing the connection route of a total of 4 lines,
It can handle all router failures. Further, in this case, the base sub-router is connected from a plurality of branch sub-routers by using an ISDN multiple line.

FIG. 2 shows the ISDN line branch side connection.
In order to effectively use the backup line (ISDN line), by applying bus wiring on the branch router side, ISD
It is possible to supplement all backup lines with N64K (2B + D) lines (because competition for backup lines can be avoided by exclusive control). In this figure,
Reference numeral 5 is for the base primary router (2Bch), 6 is for the base secondary router (1Bch), and 7 is for the base secondary router (1Bch).

FIG. 3 shows a processing flow for switching the backup line. First, the router establishes the route of the main line at the time of startup (step 31). Next, the router periodically monitors the state of the main line (step 32), and when a failure is detected,
Priority (backup line 2, backup line 3,
Switching to the backup line is performed according to the order of the backup line 3 (steps 33 to 42). At that time, be sure to check the status of the main line. When the address of the branch primary router disappears from the routing table due to the failure of the branch primary router, the connection of the backup line 4 becomes valid and the communication is performed via the branch secondary router. When the branch primary router is restored, the address of the main line becomes valid in the routing table, the route is established, and the branch primary router is restored (step 44,
45).

[0011]

According to the present invention, it is possible to secure a backup route from the terminating side router to a plurality of routers,
For all failures, with the minimum required resources
It is possible to secure high reliability. In addition, when connecting the backup line, it is expected that the line resources will be greatly reduced by applying multiple lines for the bus wiring.

[Brief description of drawings]

FIG. 1 is a configuration showing an embodiment of the invention.

FIG. 2 is a diagram showing an INS line connection configuration.

FIG. 3 is a flowchart showing a process of switching a backup line.

[Explanation of symbols]

 1 main line 2,3,4 backup line

Claims (1)

[Claims] 1. A network system in which a base system and a plurality of branch systems are connected by a dedicated line, and primary and secondary routers connected to the base system and the branch system, and a primary router of the base system and a primary branch system. A dedicated line and a backup line for connecting the router, and a backup line for connecting to the primary router of the branch system and a backup line for connecting to the secondary router of the branch system are provided in the secondary router of the branch system. A network characterized by defining priority information in the router among the plurality of backup circuits, thereby periodically polling the dedicated circuit and switching the backup path based on the priority information when a failure is detected. system.