DESIGN AND PERFORMANCE STUDY OF MULTICAST TRANSPORT PROTOCOL

Abstract

In today's world, there is a growing demand for applications with multi-user interaction such as audio and video conferencing, distribution of images, multi- user games, group communication etc. A multicast group is a collection of processes (these are members of the group) that are the destinations of the same sequence of messages. These messages may originate at one or more source sites. These processes exist in an Internet. A multicast protocol is responsible for the delivery of messages to appropriate processes in the same relative order (even if these originate at different source sites). In the present work, a general purpose multicast transport protocol is designed and implemented. This protocol resides at the transport layer. It does not need any support of multicasting at network layer. This protocol overcomes some of the problems that are encountered with existing protocols. It provides two classes of services to support the requirements of various applications. These services are unreliable and reliable. In the presented work, three message ordering properties and their solutions are discussed. Multiple group ordering property guarantees that two messages destined to two processes are delivered in the same relative order, even if they originate at different source sites and are destined to different multicast groups. "Propagation graph algorithm" solves the multiple group ordering problem by organizing the sites logically into a tree structured forest. This multiple group ordering is an important feature that is required in several applications to maintain consistency.