Performance Evaluation of the Preemptive Bandwidth Allocation Multicast Protocol

We present the Preemptive Bandwidth Allocation Multicast Protocol; a distributed multicast QoS-aware signaling protocol that adapts the users’ bandwidth requirements to the limited resources available in the network by preempting bandwidth of less prioritized streams from existing multicast groups. We assume that each multicast group will have different multicast streams with predefined quality requirements and each stream will have a priority level assigned to it. When a join request comes to the network and there is a lack of bandwidth, the communication service will try to preempt some streams of existing multicast groups to satisfy the new request without disconnecting the basic stream of any of these multicast groups. The aim is to accommodate the maximum number of users within the network with at least their minimum requirements (e.g. the I frames of an MPEG video). We also present a performance evaluation that compares two versions of the distributed multicast preemptive approach with the traditional non-preemptive one.