A Bottleneck and Target Bandwidth Estimates-Based Congestion Control Algorithm for High BDP Networks

Abstract—Two considerable problems for designing a new protocol in high bandwidth delay product (BDP) networks are bandwidth utilization efficiency and fairness to competing TCP flows. We introduce a novel congestion avoidance control algo-rithm for high BDP networks. By estimating the bottleneck and target bandwidth as the upper and lower bounds for increasing congestion window and decreasing congestion window. According to the current window size compared with those bounds, the congestion avoidance controller (CAC) adjusts the amount of appropriate congestion window increase in such a way that the sending rate stays around the point of the full link utilization. Decrease of the congestion window to a lower bound aids CAC to recover quickly after packet loss caused by either network congestion or random error. The proposal in simulation can achieve the bottleneck bandwidth utilization better than TCP-Illinois and HS-TCP do, and can improve fairness to competing flows mixed short RTT and long RTT. I