Routing control system for l3vpn service network

Abstract

A routing control system comprising a system controller and master and slave routing servers, wherein the master routing server includes a plurality of logical controllers, each of which performs routing control for each of the user networks, the system controller monitors a load state of the master routing server and migrates at least one of the plurality of logical controllers from the master routing server to the slave routing server when the load state has satisfied a predetermined condition, so that the slave routing server inherits routing control for a particular user network associated with the migrated logical controller.

Description

CLAIM OF PRIORITY[0001]The present patent application claims priority from Japanese patent application JP 2008-213250, filed on Aug. 21, 2008, the content of which is hereby incorporated by reference into this application.BACKGROUND OF THE INVENTION[0002](1) Field of the Invention[0003]The present invention relates to a routing control system and, more particularly, to a routing control system that is suitable for a Layer 3 Virtual Private Network (L3VPN) accommodating a plurality of customer or user networks.[0004](2) Description of Related Art[0005]An IP network system is composed of a plurality of communication nodes such as routers and switches. Each communication node is provided with a packet transport function unit for switching packets among a plurality of line interfaces and a control function unit connected to the packet transport function unit. Each communication node updates its route information table maintained thereon by communicating route information with the other ...

AI Technical Summary

Benefits of technology

[0020]An object of the present invention is to provide a routing control system that prevents negative impact of an increased routing control load for a particular user network from affecting on routing control for the other user networks in an L3VPN service network wherein routing control is performed by routing servers.

[0024]According to the present invention, a routing server is configured so as to perform routing control by a plurality of individual logical controllers, each of which is associated with specific one of user networks. Therefore, when an extraordinary number of routing requests occur in a particular user network, the system controller can migrate a logical controller from the master routing server to the slave routing server so as to reduce the load of the master routing server and to avoid impact on other user networks.

[0030]According to the present invention, when the processing load of the routing server increases due to a larger number of routing control packets (routing requests) transmitted from a particular user network, it becomes possible to avoid impact on the other user networks by migrating at least one of logical controllers from the master routing server to the slave routing server.

Problems solved by technology

For example, if a malfunction occurs in one of communication nodes due to a coding error in a control program or shortage of memory capacity, this malfunction has an impact on routing control across the entire network system and may give rise to disrupted communication on a particular route according to circumstances.

However, when a plurality of user networks are connected to the L3VPN service network, the load of the routing system increases on account of various factors.

If a new customer joins in the L3VPN service, for example, the load of the routing system increases because of increasing in the number of networks to be controlled.

Further, if a loop has occurred in an Ethernet (registered trademark) serving as a user network due to incorrect cable connection, for example, there is a risk that a storm of routing control packets (routing requests) transmitted from routers in the user network may occur.

In this case, a burst of routing control packets not foreseen by the routing protocol will be transmitted into the routing system (route server), thereby causing a surge in the processing load on the route server.

Failure occurred in one of the routers in the user networks and bugs involved in routing control software running on the router may result in a burst of routing control packets.

Transmission of a burst of routing control packets from a user network by a malicious user also causes a surge in the load on the route server.

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