Improving TCP's Robustness to Long Connectivity Disruptions
Alexander Zimmermann, Daniel Schaffrath, Arnd Hannemann · 2008
TCP was designed with fixed, wired networks in mind. As a result TCP performs suboptimal in networks where changes to path characteristics are frequent, e.g., in wireless mesh networks. One reason for the performance degradation is TCP's over-conservative behavior in face of long connectivity disruptions. In this paper we introduce a novel methodology how connectivity disruption indications provided by standard ICMP messages may be exploited to improve TCP's performance. We implement an RTO revert strategy that enables earlier detection of whether connectivity to a previously disconnected peer node has been restored or not. Thereby, connections relish more throughput and less delay. Our scheme is a sender only modification which fully respects the TCP congestion control principles.