Improving TCP´s Robustness to Long Connectivity Disruptions

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.