Advanced centralized RWA protocol for WDM networks

In this paper we present the design of an Advanced Centralized RWA Protocol (ACRP) in which the cost of a lightpath is computed based on its number of available free wavelengths and number of wavelength conversions. Centralized Management System (CMS I) assigns optimal primary and backup lightpaths. CMS II updates the optimal primary and backup lightpaths as and when the number of free wavelengths of primary lightpath reaches the threshold value `N≤ 4´. In case of failure the data will be rerouted through the backup lightpath and very next lightpath with best cost is assigned as backup lightpath. The advantage of this protocol is that the tasks are shared using two CMS which improves the computation bottleneck and also if one fails the other will take over the entire process. By simulation results, we showed that our proposed protocol has minimal request rejection and set-up time.