Multicast Redux: A First Look at Enterprise Multicast Traffic Elliott Karpilovsky Lee Breslau Princeton University AT&T Labs – Research
[email protected] [email protected] Alexandre Gerber Subhabrata Sen AT&T Labs – Research AT&T Labs – Research
[email protected] [email protected] ABSTRACT 1. INTRODUCTION IP multicast, after spending much of the last 20 years as IP multicast [1, 2], which provides an e±cient mechanism the subject of research papers, protocol design e®orts and for the delivery of the same data from a single source to limited experimental usage, is ¯nally seeing signi¯cant de- multiple receivers, was ¯rst proposed more than two decades ployment in production networks. The e±ciency a®orded ago. It was deployed experimentally on the MBone [3] in the by one-to-many network layer distribution is well-suited to early 1990s and was the subject of a signi¯cant amount of re- such emerging applications as IPTV, ¯le distribution, con- search into scalable and robust intra- and inter-domain rout- ferencing, and the dissemination of ¯nancial trading infor- ing protocols [4, 5, 6]. The MBone, an overlay used primarily mation. However, it is important to understand the behavior to support audio and video conferencing between multicast- of these applications in order to see if network protocols are capable networks around the Internet, grew rapidly. How- appropriately supporting them. In this paper we undertake ever, the initial enthusiasm for multicast did not translate a study of enterprise multicast tra±c as observed from the into widespread success. The MBone eventually declined, vantage point of a large VPN service provider.