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. 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 operating over dynamic topologies.