On providing quality-of-service control for core-based multicast routing

In this paper, we develop efficient admission control tests for member join/leave and its associated state refresh and update procedures for receiver-initiated core-based multicast routing, e.g., core based tree (CBT) protocol, to allow construction of QoS-capable multicast trees, while making the minimum possible impact on the existing infrastructure. Specifically, we (i) derive sufficient conditions for a multicast tree to maintain its QoS; (ii) devise effective admission tests to verify whether or not a group member may join the multicast tree at adequate QoS, while not violating existing QoS guarantees to other on-tree members; and (iii) identify the minimum set of state information required for the admission tests and develop a soft state refresh and update procedure. Finally, we validate the effectiveness of the proposed mechanism by incorporating it into the CBT protocol, and evaluate it via event-driven simulations in terms of the probability of join requests being rejected, message overhead, and scalability