An Extension of the TCP Steady-State Throughput Equation for Parallel Flows and Its Application in MulTFRC

In the first part of this paper, we present a simple extension of the well-known TCP steady-state throughput equation that can be used to calculate the throughput of several flows that share an end-to-end path. The value of this extension, which we show to work well with simulations as well as real-life measurements, is its practical applicability. Thus, in the second part of this paper, we present its application in MulTFRC, a TCP-friendly rate control (TFRC)-based congestion control mechanism that is fair to a number of parallel TCP flows while maintaining a smoother sending rate than multiple real TFRC flows do. MulTFRC enables its users to prioritize transfers by controlling the fairness among them in an almost arbitrary fashion.