Differentiated services and its importance in fault tolerant WDM optical network

The focus of this paper is on developing and evaluating a practical methodology for determining if and when different types of traffic can be safely managed within different class of services and satisfying reliability criteria. Our approach relies on an analytical model developed under a number of simplifying assumptions, which we test using several real traffic traces under fault condition corresponding to different types of services for clients and satisfying reliability degree for the connection request of link failure and searching of backup path dynamically that can give rise to substantial performance deviations with different class of service that is high, medium and low class. The results show that a hop-by-hop, link-state routing protocol, like Open shortest path first, can be extended to efficiently support class-based Quality of Service traffic differentiation. We have used auxiliary graph based open shortest path heuristic (AGBOSPH) technique to select back up path as a restoration strategy. It is found that average bandwidth utilization for large scale network is 12.62% less than previous studies. At the time of starting both have similar performance but under restoration AGBOSPH is more satisfactory and give excellent performance for higher scale of network. The proposed algorithm shows improvements at all traffic loads. At heavy loads the improvement is more pronounced and average improved performance for high degree of traffic load is of the order of 28.56%.