This paper presents a comparative study between the dynamic survivability approaches in WDM mesh networks. The paper focuses on the diverse routing and the p-cycle approaches to protect mesh networks against single span failure under dynamic traffic. The computational complexity and the blocking performances of both approaches are analyzed and compared. Simulation results suggest that the p-cycle approach has better blocking performance than the diverse routing approach. Additionally, the lower computational complexity of the p-cycle approach algorithm makes it more suitable, especially at highly dynamic traffic. As a result, the p-cycle approach scales better with the network size and the dynamic nature of the traffic than the diverse routing approach. Therefore, the p-cycle approach has presented itself as a better option than the diverse routing to solve the survivability problem in dynamic WDM wavelength-routed networks. Other advantages of the p-cycle approach include their fairness to requests with long routes.

The ever increase in the Internet traffic resulted in an increase in the number of wavelengths per fibre in WDM networks. Consequently, the required number of optical ports increases which accordingly increases the cost of the optical cross connect and the complexity of the routing and wavelength assignment algorithms. As a result, the multi-granular switching concept was introduced to reduce the cost of the optical cross connect and simplify the complexity of its management algorithms. This paper proposes a new heuristic algorithm, based on the Multi-Granular traffic concept, to set up static multi-granular paths in optical networks. The objective of the new algorithm is to minimize the total weighted port count that is required to set up a given set of static multi-granular traffic demands on a given network. The new algorithm is tested and its performance is compared with other previously proposed algorithms.