Increasing Robustness of XCP (eXplicit Control Protocol) for Dynamic Traffic

XCP (eXplicit control protocol) has been proposed as an efficient transport protocol for a wide-area and high-speed network. XCP is a transport-layer protocol that performs congestion control using explicit feedback from routers. In the literature, many simulation-based performance studies of XCP has been performed. However, the effect of traffic dynamics on the XCP performance has not been investigated. In this paper, through simulation experiments, we first show that XCP has the following problems: (1) utilization of the bottleneck link is lowered due to XCP traffic dynamics, and (2) in environment where non-XCP traffic and XCP traffic coexist, control of XCP becomes unstable. We then propose XCP-IR (XCP with increased robustness) that operates efficiently even for dynamic traffic. Through simulation experiments, we show that XCP-IR operates efficiently even for dynamic traffic.