Cost analysis and optimization for IP multicast group management

This paper studies the system parameters that affect the total cost of managing the multicast group on a router. A Petri net model is first proposed to describe the states and transitions of the multicast group management. Based on this model, a delayed vacation queue, extended from a simple M/M/1 queue, is used to analyze the total cost of the multicast group management under various system conditions. The formal analysis reveals that the total cost of the multicast group management is minimized when a router delays a certain time to send its pruning messages to upstream routers. Furthermore, a formula is derived to calculate the optimal delay time for sending the pruning messages to minimize the multicast group management cost. To validate this cost analysis model, an IP multicast group management module is added to the NS-2 simulator to simulate the IP multicast group management. The simulation results under various system parameters are consistent with the results obtained by formal analyses, validating the proposed cost analysis model.