Predicting the Performance Impacts of Multicast Network Workloads

This paper addresses the problem of multicast (i.e., mul-tipoint) routing in computer networks carrying a mix of uni-cast and multicast traac. In particular, we derive a closed form mathematical expression to predict the average link usage for multicast calls in a two-dimensional rectangular mesh network. The analytical expression is used to evaluate the relative performance of three simple multicast routing techniques: M-Unicast, Conference Call, and Core-Based Trees. Simulation experiments are then used to assess the accuracy of the analytical model. The results show that, among the three routing models considered, the Core-Based Trees model has the lowest average links required per multicast recipient. Simulation results show that the analytic model is highly accurate: always within 10%, and often within 5% of the results obtained by simulation. The accuracy of the analytical model degrades only slightly as the network load increases.