Overcast is an application-level multicasting system that can be incrementally deployed using today's Internet infrastructure. These properties stem from Overcast's implementation as an overlay network. An overlay network consists of a collection of nodes placed at strategic locations in an existing network fabric. These nodes implement a network abstraction on top of the network provided by the underlying substrate network. Overcast provides scalable and reliable single-source multicast using a simple protocol for building efficient data distribution trees that adapt to changing network conditions. To support fast joins, Overcast implements a new protocol for efficiently tracking the global status of a changing distribution tree. Results based on simulations confirm that Overcast provides its added functionality while performing competitively with IP Multicast. Simulations indicate that Overcast quickly builds bandwidthefficient distribution trees that, compared to IP Multi...
John Jannotti, David K. Gifford, Kirk L. Johnson,