Analysis of UDP performance enhancement proxies for mobile users

Long fat networks (LFNs) are characterized by "large" bandwidth-delay products and typically have one or more satellite hops along an end-to-end path. Performance of responsive protocols, like TCP, is severely impacted by their congestion control mechanisms. In this paper, we analyze the interaction of a performance enhancing proxy (PEP) technique that aggregates flows before sending over a satellite network to mobile users. While such a technique has been shown to increase the performance of end-to-end transport, the effect of competing UDP-based PEP traffic on the performance of TCP flows has not been studied. Using both simulation and emulation we show that the impact of protocols/applications using UDP on competing TCP flows can be mitigated if the magnitude and frequency of the sending UDP bursts are carefully controlled.