Analyzing Steady State and Transient State Performance of Transmission Control Protocol in the Internet

The Internet uses a window-based congestion control mechanism in TCP (Transmission Control Protocol). In the literature, there have been a great number of analytical studies on TCP. Most of those studies have focused on the statistical behavior of TCP by assuming a constant packet loss probability in the network. However, the packet loss probability, in reality, changes according to packet transmission rates from TCP connections. In this thesis, we explicitly model the interaction between the congestion control mechanism of TCP and the network as a feedback system. Namely, we model the congestion control mechanism of TCP as a dynamic system, where the input to the system is the packet loss probability and the output is the window size. Inversely, we model the network as a dynamic system, where the input is the window size and the output is the packet loss probability. The network is modeled by a M/M/1/m queueing system by assuming an existence of a single bottleneck link. 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. Through numerical examples, it is shown that the bandwidth–delay product of a TCP connection significantly affects its stability and transient performance. It is also