An efficient flooding algorithm for improving network performance in optical WDM networks

Abstract

In any networking environment, network and resource information has to be maintained periodically for re-routing the traffic. Especially in fault tolerant optical networks, after the faults are detected and recovered, the network topology changes have to be constantly configured for correct light path decisions to be made. In order to maintain correct routing tables and also to prevent blocking of forthcoming calls by the failed connection, the flooding messages have been broadcast to all nodes. When every node in the network floods the messages, problems arise of excessive redundancy of messages, resource contention and signal collision. This causes high protocol overhead and interference with the existing traffic in the networks. In this paper, lazy flooding algorithm is analysed and simulated by comparing the performance of all-flooding method and threshold flooding. Here, instead of flooding for each channel status update, such as to be changed from available to occupy or vice versa, we hold the process of update till it reaches certain points. The simulation results shows that the proposed flooding method achieves reduced blocking probability with increased throughput thereby increasing the scalability of the network.