Publication

Abstract : In this paper we present the design of a Centralized dynamic RWA protocol (CDRP) in which the number of available free wavelengths and blocking probability parameters are considered for selecting the optimal paths. In this protocol whenever a request comes to a source it sends the information to Centralized Management System (CMS-1) and the CMS-1 calculates number of available free wavelengths on each path and simultaneously the CMS-I intimate the source to transmit the request through all the paths. Based on the number of packets reached the destination CMS-1 computes the blocking probabilities of all the paths and assigns Optimal primary and backup paths based on blocking probability and number of available free wavelengths. CMS-2 repeats the above procedure when the blocking probability of optimal path reaches threshold value 'N'. In case of fiber level failure the data will be rerouted through the backup path and very next path with least blocking probability and more number of available free wavelengths is assigned as backup path. The advantage of this algorithm is that it identifies an optimal and backup path by blocking probability and number of available free wavelengths. In addition to that the tasks are shared by using two CMS, If one fails the other will take over the entire process and also our approach is self regulating, i.e., it automatically adapts to the traffic load variation across the network. By simulation results, we showed that our proposed protocol has minimal blocking probability and high throughput.