The Range of Parameter α for the Stability of FAST TCP

FAST TCP as a new variant of TCP has attracted much attention because it can sustain high throughput and utilization. However, the parameters play a vital role in the performance of FAST TCP. This paper investigates the stability of FAST TCP based on a discrete-time model. According to the model, we derive the range for congestion window tuning parameter α, using the characteristic root equation of closed-loop system and the Routh-Hurwitz stability criteria. The upper bound of α gives a new guideline to design stable networks. Furthermore, the ns simulations demonstrate the validity of parameter condition for FAST TCP.