Scalability Issues for Reliable Multicast Protocols

Many emerging applications are based on multimedia group communication. Mul-ticast communication is a transmission mode that is now supported by a variety of local and wide area networks. Many group applications require a full reliable data transfer to all receivers. A problem in this context is how to provide a full reliable data transmission to a large number of receivers while still exploiting the advantages of multicast communication, such as bandwidth saving, and maintaining a suitable performance in a heterogeneous environment. This issue is generally referred as the problem of reliability versus scalability. In this paper we present diierent classes of multicast reliable protocols according to an existing taxonomy and discuss how well each of them handle large number of receivers.