Design of controller for XCP router achieving efficient and fair bandwidth allocation
Hairui Zhou, Guanzhong Dai, Fanghong Ye, Huixiang Zhang · 2009
As the product of bandwidth and latency increases, TCP becomes inefficient and prone to instability, regardless of the queuing scheme. The eXplicit Control Protocol (XCP) is a novel and promising congestion control protocol that outperforms TCP in terms of efficiency, fairness, persistent queue length, packet loss rate and convergence speed. However, in a multi-bottleneck environment, XCP may cause some bottleneck links to be under-utilized, and a flow may only receive a small fraction of its max-min fair allocation. In this paper, according to the robust control theory, with the help of a recently developed Lyapunov-Krasovskii functional, we propose an XCP bandwidth compensation algorithm based on state feedback (S-XCP). Extensive simulations have shown that S-XCP achieves efficient and fair bandwidth allocation in a multi-bottleneck environment. Simulations also have shown that S-XCP preserves the good properties of XCP, including fast convergence, low persistent queue length and negligible packet loss rate.