On virtual circuit routing and re-routing in packet-switched networks

An examination is made of the effects of using different network status information in initially placing and dynamically rerouting virtual circuits in packet-switched networks. In the case of virtual circuit rerouting, the effects of call tear down/reestablishment times and resequencing delays are considered. Both analytic and simulation results are presented. The analysis of a dynamic rerouting policy is based on first decomposing the network model and then using a matrix-geometric solution of a continuous-time Markov chain model. The results indicate that assigning virtual circuits on the basis of the number of virtual circuits on a path provides better performance than using the number of unacknowledged packets, except when virtual circuit holding times are extremely short