Multiparty videoconferencing using IP multicast

Abstract

This paper examines the data distribution issue of multiparty videoconferencing over the IP Internet. IP multicast, which supports efficient one-to-many communications, is envisaged to provide data transports for this type of applications. While different videoconferencing scenarios require different delay requirements ranging from several hundred milliseconds to a few seconds, existing multicast routing protocols provide only one route, which may either fall short of the requirement or provide more than what is needed thereby wasting network resources. We present a new protocol named Core Group Based Tree, which has the dynamic feature of splitting and merging multicast trees in response to the distribution of participants' locations and the delay requirements of the multicast application. A modified version of the Core Based Tree protocol, this new protocol inherits CBT's scalability and simple system design but has an improved delay performance. Our simulation results show significant improvements over CBT on both the maximum delay and the average delay performances. ©2004 Copyright SPIE - The International Society for Optical Engineering.