QoS based routing algorithm in Integrated Services Packet Networks

In this paper we study QoS based routing algorithm for supporting resource reservation in high-speed Integrated Services Packet Network (ISPN). Recently, this problem was proved to be NP-complete. However, when the considered QoS constraints are bandwidth, delay, delay jitter, and loss-free, we have shown that by employing Weighted Fair Queueing (WFQ) service discipline, the complexity of the problem could be reduced to that of shortest path routing without any QoS constraints. Then such a multiple QoS constrained route could be searched in polynomial time. We also present that routing algorithm (called 'QoSR(BF)'), which is a modified version of Bellman-Ford shortest path algorithm. Simulation results show that QoSR(BF) has better performance compared to the existing QoS routing algorithms.