Mobile multicast proxy

This paper describes experiments for providing mobile users with continuous access to IP multicast groups using a multicast proxy. Although it is usually possible for a roaming node to directly connect with the multicast tree, we show that the costs can be prohibitive, especially in highly dynamic environments such as that proposed for the tactical army battlefield. Using mobile IP is also considered, but shown to provide less flexibility and efficiency than the more general multicast proxy. We describe the implementation of the multicast proxy on a Linux PC platform through modifications to the “routed” and IGMP code. The performance is compared using a version of the high performance test program “ttcp” modified for multicast. We also show how protocol boosters can improve performance for mobile users