Explicit Multicast (Xcast) Basic Specification
While traditional IP multicast schemes[1112] are scalable for very large multicast groups, they have scalability issues with a very large number of distinct multicast groups. This document describes Xcast (Explicit Multi-unicast (Xcast)), a new multicast scheme with complementary scaling properties: Xcast supports a very large number of small multicast sessions. Xcast achieves this by explicitly encoding the list of destinations in the data packets, instead of using a multicast group address. This document discusses Xcast concepts and options in several areas; it does not provide a complete technical specification at this point.