As the multicast-capable part of the Internet continues to evolve, important questions to ask are whether the protocols are operating correctly, the topology is well connected, and the routes are stable. A critical step in being able to answer these questions is to monitor the traffic and network operation. In this paper, we analyze characteristics of the multicast infrastructure over the last three years using monitoring data collected from several key routers. Specifically, we focus on analyzing two characteristics of the infrastructure: size and stability. The size analysis focuses on counting the number of connected hosts and networks, and analyzing how the size of the infrastructure has changed over past three years. Second, the stability analysis focuses on examining persistence, prevalence, and visibility of routes across the topology. From our analyses, we identify a number of problems with multicast routing and their effect on the connectivity of certain multicast networks. Moreover, we offer insight into the evolution and future of multicast in the Internet.
展开▼
