While support for IP multicasting continues to spread enabling new applications, an increasing number of hosts connects to the worldwide Internet via low bandwidth Point-toPoint links, such as wireline or wireless telephone lines. In this paper we discuss existing proposals for local and wide area IP multicasting and their implications for Point-to-Point links, identify problems with their integration in this environment, and propose alternative special purpose mechanisms to solve these problems. The main problems are overhead due to IGMP leave latency and unnecessary continuous probing of potentially power constrained hosts. Our solution is an alternative to IGMP mechanisms based on join/leave messages for tracking group membership over PtP networks. After presenting the implementation requirements of our proposed and the existing mechanisms, we compare them with respect to performance, interoperability, robustness and implementation complexity, demonstrating that our join/leave prot...
George Xylomenos, George C. Polyzos