Fluid-flow analysis of TCP Westwood with RED

This paper concerns TCP Westwood, a recently developed modification of TCP, in combination with RED queue management. We develop a fluid-flow model of the protocol, and use it to study both equilibrium and dynamic features. On the equilibrium side, we identify the scaling of window with loss-probability, and compare it to TCP NewReno. We also use the model to find the boundary of stability, beyond which we see large oscillations; we find that the stable region of TCP Westwood is enhanced with respect to TCP NewReno. Furthermore we show preliminary evidence that oscillations, when they occur, have a limited impact on network throughput.