A Synchronous Multicast Application for Asymmetric Intra-campus Networks: Definition, Analysis and Evaluation

摘要

In this paper, we propose and analyze an application called SOMA (Synchronous Multicast Application) which offers multicast file transfer service in an asymmetric intra-campus environment. For efficient bandwidth utilization, SOMA uses IP multicasting. Since TCP cannot be used in multicast situations, we also propose a transport protocol involving a flow control algorithm. This algorithm adapts the protocol window size and the overall application transfer rate to the minimum network capacity, allowing synchronism and reacting quickly when congestion arises at any router. The protocol behavior has been intensively tested in a lab, using a mixture of wired and wireless networks. The paper also explains how to capture and post-process SOMA network traffic. In addition, we develop a mathematical model to validate the most important protocol parameters. The methodology employed to define, analyze and evaluate this protocol is, indeed, another contribution and can be easily extended to other multicast protocols.