Performance evaluation of multicast communication in packet-switched networks

In this paper we describe the theoretical background and practical application of QNA-MC (Queueing Network Analyzer supporting MultiCast), a tool for the analytical evaluation of multicast protocols. QNA-MC is based on the QNA tool which (approximately) analyses open networks consisting of GI|G|m nodes. While the input of the standard QNA tool is restricted to non-deterministic (probabilistic) routing or deterministic unicast routes, QNA-MC allows for a more general input in the form of multicast routes. As in real multicast communication, packets leaving a particular node can be copied and deterministically routed to several other nodes. In order to analyse such networks QNA-MC converts the multicast routes to a suitable input for standard QNA. From the results delivered by QNA, QNA-MC then derives several performance measures for multicast streams in the network. A validation of QNA-MC, via a comparison to simulation results, shows that QNA-MC yields very good results. Finally, we give a detailed application example by evaluating different multicast routing algorithms for a realistic video conferencing scenario in the European MBONE.