Congestion detection in WDM Networks

To investigate a new ant-based agent algorithm for providing survivable routing in WDM network. The major problem in survivable routing WDM network is routing wavelength and assignment (RWA) problem, It sets up light path by routing and assigning a wavelength to each connection such that no light path use the same wavelength on same link Initially, in the path, a major part of the bandwidth is allocated for primary path and this part can not be shared by other paths. Fraction of the bandwidth is allocated for backup path and this can be shared by other disjoint paths. The disjoint path can be primary or backup path. The residual bandwidth is used for future primary and backup paths computations. When the connection request arrives to the source, it looks in its pheromone and load table and send connection request (CNREQ) message to the destination along with feasibility and load values of paths. Upon receiving the CNREQ, the path that has higher feasibility value and the load value lesser than ThLOAD can be selected by the destination for further processing. Using NS-2 simualtion we show that the proposed ant based routing achives better channel utilization and throughput