Analysis of TCP flow control for high speed networks: Case of two nodes in tandem

In this paper we examine the problem of evaluating the performance of TCP connections in a wide area network. Our approach combines analytical and simulation methods. Our model is represented by two finite buffer queues which are shared by two connections. One being the reference TCP connection and the other representing the exogenous traffic (in simulation we consider the UDP traffic). This model, which is an enlarged model with two nodes in tandem shared, is unlike previous simplified models with a single bottleneck node. We use fluid approximation to analyze the behaviour of the TCP. We derive closed-form expression for the average throughput as a function of buffering and characteristics of exogenous traffic. Finally, we use simulation, by network simulator (NS), to validate the model, and we find in general good correlation with the analytic results. This means that we can extend our model at more than two nodes in tandem.