LMPS: Localized Multi-path Selection for QoS Routing in VoIP Networks

Localized QoS routing techniques were proposed to achieve acceptable performance without exchanging global state information over the network. In such techniques, the ingress nodes estimate the network state and make the routing decision locally, hence reducing the signaling traffic at core routers. However, using only locally collected information to make routing decision is not a completely reliable technique to achieve trusted QoS performance. The Localized Multi-Path Selection (LMPS) scheme is proposed in this paper for connection-oriented bandwidth-aware flows to overcome the common drawbacks of the localized techniques. The LMPS technique is a multi-path selection algorithm, which selects paths that are capable of satisfying the requested bandwidth requirement of an incoming call, while at the same time trying to avoid the overloaded links to minimize the overall blocking ratio in the network. We demonstrate through extensive simulations and comparisons with a fully localized approach known as virtual capacity routing (VCR) and a shortest-widest multipath scheme based on QOSPF that the LMPS scheme provides good performance.