Abstract

Although IP-multicast has been proposed and investigated for years, there are major problems inherent in the IP-multicasting technique, e.g., difficulty to scale up the system, difficulty in allocating a globally unique multicast address, complexity in supporting higher level features such as reliable data transfer and congestion/flow control, more importantly, difficulty to deploy on the current Internet infrastructure due to necessity to change many core routers. Recently, End-System Multicast (ESM) has been proposed as an alternative solution so that multicasting services can be quickly deployed. In this paper, we consider the "architectural" and "optimization" issues on designing an ESM-tree. Specifically, we present a distributed algorithm on how to create and maintain an ESM-tree. We propose a distributed algorithm to perform tree optimization (TO) so that an ESM-tree can dynamically adapt to the changing network condition (e.g., drop in transfer bandwidth) so that the nodes within an ESM-tree can receive data more efficiently. The distributed algorithm has the important theoretical properties that at all times, a tree-topology can be maintained and any node joining, leaving, as well as any tree optimization operation will not "partition " the underlying ESM-tree. Therefore, our work can be used to provide an efficient architectural infrastructure for ESM services. We have implemented a prototype ESM system and carried out experiments to illustrate the effectiveness and the performance gains of our ESM optimization protocol.

Citations