A Cost-Based Approach for Analysing the Overheads of Multicast Protocols in Non-Strictly Hierarchical Networks

In this paper we study the properties of protocol independent multicast (PIM) in non-strictly hierarchical network environments. In particular, we investigate the cost (overhead) behaviour of the PIM protocols i.e., sparse mode (PIM-SM), dense mode with flood and prune mechanism (PIM-DMFP), dense mode with state refresh (PIM-DMSR), and source specific multicast (PIM-SSM). By assuming that the links in the networks are symmetrical, we assign equal values to both up and down links and then specify analytical models to evaluate the performance of the protocols in static multicast group scenarios. We determine the overhead of setting up the protocols in terms of the number of links a packet traverses. We generate numerical results to analyse the effectiveness of our model. Our results confirm that the PIM-SM protocol remains superior over the other three variants in most mean group sizes