Modeling TCP reno performance: A simple model and its empirical validation

The steady-state performance of a bulk transfer TCP flow (i.e., a flow with a large amount of data to send, such as FTP transfers) may be characterize d by the send rate, which is the amount of data sent by the sender in unit time. In this paper we develop a simple analytic characterization of the st eady-state send rate as a function of loss rate and round trip time (RTT) f or a bulk transfer TCP flow. Unlike the models in [7]-[9], and [12], our mo del captures not only the behavior of the fast retransmit mechanism but als o the effect of the time-out mechanism. Our measurements suggest that this latter behavior is important from a modeling perspective, as almost all of our TCP traces contained more time-out events than fast retransmit events. Our measurements demonstrate that our model is able to more accurately pred ict TCP send rate and is accurate over a wider range of loss rates, We also present a simple extension of our model to compute the throughput of a bul k transfer TCP flow, which is defined as the amount of data received by the receiver in unit time.