Steady state and transient behavior analyses of TCP connections considering interactions between TCP connections and network

摘要

The Internet uses a window-based flow control mechanism in TCP (Transmission Control Protocol). In the literature, there have been a significant number of analytical studies on TCP. Most of those studies have focused on the statistical behavior of TCP by assuming a constant packet lost probability in the network. In our previous work, we have presented an approach for modeling the network as a single feedback system using fluid flow approximation and queuing theory. In this paper, by utilizing and extending our previous work, we analyze the steady state behavior and the transient behavior of TCP. We first derive the throughput and the packet loss probability of TCP and the number of packets queued in the bottleneck router. We then analyze the transient behavior of TCP using a control theoretic approach, showing the influence of the number of TCP connections and the propagation delay on its transient behavior of TCP. We show that the bandwidth delay product of a TCP connection significantly affects its stability and transient performance. We also show that the network becomes more stable as the number of TCP connections and/or the amount of background traffic increases.