A New Multicast Scheme for Small Groups

Multicast is a technology that allows an application program to send data to more than one destination. An application program that uses multicast sends a single copy of its data and the network delivers the data to a set of destinations on the application's behalf. Multicast is important since it enables new classes of applications such as video distribution, audio and video conferencing, networked collaborative work environments, multiparty networked games etc. The Internet community has done a significant amount of work on IP multicast over the last decade [1-10] and as a result, there are a number of multicast applications that are used today on the Mbone, the multicast-capable virtual network that is layered on top of (portions of) the Internet [10]. Today's multicast schemes are scaleable in the sense that they can support very large number of distinct multicast groups, such as a large number of small audio & video conferences, for example. In this paper, we describe a new scheme for multicast that complements the existing schemes. Whereas the existing schemes can support a limited number of very large multicast groups, the new scheme can support a very large number of small multicast groups for conferencing or other applications.