Performance Analysis of Modified DORA for Constraint Based WDM Networks

Wave length division multiplexing has emerged as a promising technology for backbone networks. The optical layer based on WDM technology provides optical routing services to the upper layers. We consider large optical networks in which nodes employ wavelength-routing switches and wavelength converters which enable the establishment of wavelength-division multiplexed channels called light paths, between node pairs. We propose a algorithm called modified DORA which solves the routing and wavelength assignment of light paths in such networks. We studied the performance of proposed algorithm for a standard NSFNET for 10 nodes and 15 links and analyzed the blocking probability for various cases. We studied the dynamic routing algorithm. We modified the algorithm to suit for WDM networks. We compare it with the exhaust routing in terms of blocking probability, channel utilization and complexity