TCP Westwood with Limited Congestion Window
Mohamed Tekala · 2009
TCP Westwood (TCPW) is a sender side modification of TCP congestion control. It estimates the connection rate by monitoring the acknowledgment reception rate; this estimation is used to compute congestion window and slow start threshold. The sender continuously computes the current eligible rate estimation: upon a packet loss the sender sets the slow start threshold and the congestion according to this estimation. In this work, we modify TCPW to limit its congestion window some value higher than the estimated slow start threshold. This mechanism avoids buffer overflow hence multiple losses for steady states while also maintains full utilization of the bottleneck link.The limited congestion window algorithm also prevents the periodic oscillation of the senderpsilas windows size, thus result flows experience stable round trip time that produces less jitter. The proposed method is numerically evaluated by simulations.