Multicast Extensions to QOSPF

QOSPF [6-8] is a well-known link state based unicast QoS routing protocol. It is a precomputation-based approach with the strength of low routing latency but suffers from high control and storage overheads. Its overhead will be exacerbated not only for large-scale network but also for the extension to support multicast routing. Thus, few researches strive to directly extend the work of QOSPF to multicast capability. In this paper, we introduce a simple multicast extension version of QOSPF protocol named MQOSPF (Multicast extension to QOSPF), which uses a scope-limited advertising scheme to limit both control and storage overheads. Through extensive simulations, its excellent performances on low routing latency, high success rate to find a feasible attachment path to existing multicast tree and to construct low cost multicast delivery tree are demonstrated.