Localized QoS Routing with End-to-End Delay Guarantees

Localized Quality of Service (QoS) routing has been recently proposed as a promising alternative to the currently deployed global routing schemes. In localized routing schemes, routing decisions are taken solely based on locally collected statistical information rather than global state information. This approach significantly reduces the overheads associated with maintaining global state information at each node, which in turn improves the overall routing performance. Routing with delay guarantee involves path-constrained requirements, which are harder and more complex to satisfy than routing with bandwidth guarantee, which involves only link-constrained requirements. In this paper we introduce a Localized Delay-Constrained QoS Routing algorithm (LDCR), which can guarantee the end-to-end delay requirements for network flows. The performance of the proposed algorithm is evaluated against the well-known global shortest path routing algorithm (Dijkstra) and against a modified delay-based version of the localized CBR. Simulation results have shown considerable performance improvement achieved by the proposed algorithm in terms of the overall network blocking probability.