Impact of network dynamics on end-to-end protocols: case studies in reliable multicast

End-to-end protocols measure network characteristics and react based on their estimates of network performance. Network dynamics can alter the topology significantly, and thereby affect protocol operation. Topology changes may result in routing pathologies (such as route loops, packet interleaving), changes to the end-to-end path characteristics, network partition etc, that then impact the performance of end-to-end protocols. This paper presents methodologies to evaluate an end-to-end protocol in the presence of network dynamics using a simulator. In the paper, we evaluate a reliable multicast transport protocol over dynamic topologies and study its adaptivity to topology change. We present a systematic evaluation of the adaptive timer mechanisms in Scalable Reliable Multicast (SRM). The timer mechanisms are evaluated under simple topology changes, as well as under network partition conditions. The paper concludes by posing a number of open research questions about the behaviour of different reliable multicast mechanisms when The work of K. Varadhan and D. Estrin was supported by the Defense Advanced Research Projects Agency (DARPA) under contract number ABT63-96-C-0054. The work of S. Floyd was supported by the Director, Office of Energy Research, Scientific Computing Staff, of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098, and by ARPA grant DABT6396-C-0105. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the DARPA or the U.S. Department of Energy. Copyright 1998 IEEE. Published in the Proceedings of ISCC’98, 30 June 2 July in Athens, Greece. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works, must be obtained from the IEEE. Contact: Manager, Copyrights and Permissions / IEEE Service Center / 445 Hoes Lane / P.O. Box 1331 / Piscataway, NJ 08855-1331, USA. Telephone: + Intl. 732-562-3966. operating over dynamic topologies.