Design and analysis of multicasting experiment based on PIM-DM

In this paper, we build a PIM-DM enabled network experiment testbed and gain an appreciation of the working protocols and routing characteristics involved. Through this experiment design, we can examine and discover that PIM-DM makes efficient use of the network by not wasting bandwidth. This is accomplished through the interaction of IGMP, and each stage of the flood-and-prune mechanism examined in detail. The detailed procedure has explored the scenario, that a router receives the multicast data on the interface closest to the source, and then forwards the traffic to all other interfaces. Flooding occurs periodically. It is used to refresh state information, such as the source IP address and multicast group pair. If the router has no interested receivers for the data, and the routing table becomes empty, and the router sends a prune message upstream to stop the delivery of multicast traffic. Based on this design and analysis, students can find that PIM-DM is a stable and workable solution for a dedicated scale multicast domains, and gain the working principle intuitively in detail.