IP multicast group management for point-to-point local distribution

We examine the applicability of existing IP multicast mechanisms for point-to-point links such as wired and wireless telephone lines. We identify problems such as overhead due to IGMP leave latency and unnecessary probing of hosts, both important issues for power constrained mobile hosts and low bandwidth wireless links. We propose alternative mechanisms that preserve the IP multicasting model, but employ join–leave messages to track group membership. We describe the implementation requirements of our mechanisms and compare them to existing ones with respect to performance, mobile power efficiency, interoperability, robustness and implementation complexity, demonstrating that the join–leave approach is uniformly superior for this environment.