MULTICAST GROUP-BEHAVIOR IN THE INTERNETS MULTICAST BACKBONE (MBONE)

The multicast backbone (MBone) is a network overlaying the global Inte rnet and designed to support multipoint applications. In this article, the authors first give an overview of the development and architectur e of the current MBone. One important characteristic of the MBone is i ts reliance on IP multicast which allows receivers to join and leave g roups asynchronously. The authors describe the Mlisten data collection tool that was created to provide a mechanism for capturing informatio n about when members join and leave a multicast group. Using data coll ected with Mlisten, the authors present statistics about some of the M Bone sessions they monitored. Results are provided for key parameters including multicast participant interarrival times and participant dur ations, multicast tree size and characteristics, and intersession rela tionships. Collecting data about MBone usage can improve our understan ding of how multicast communication and real-time protocols are being used today.