Nonlinear dynamics in Internet congestion control model with TCP Westwood under RED

Abstract

This article develops a discrete time dynamic feedback model of a congestion control system for a simple network with TCP Westwood (TCPW) connections and a single bottleneck link with random early detection (RED) gateway. By using this model, the nonlinear dynamics of the TCPW/RED network are analyzed and its parameter sensitivities are studied. It is shown that periodic doubling bifurcation occurs when the RED control parameters or other parameters are varied. By theoretical analysis, the fixed point, the critical value of parameters and the nature of the bifurcation are determined. Moreover, by using bifurcation diagrams and Lyapunov exponent, the result of theoretical analysis is validated and the bifurcation and chaotic phenomena are numerically studied of the congestion control system with TCPW connections and RED gateway.