Abstract: DSVR, a dynamic threshold and verying rate TCP Slow-Start algorithm, is proposed. The key technologies of Vegas and TCP Westwood are applied to the first slow start process in DSVR, which dynamically configures the TCP Slow-Start threshold and adaptively adjusts the increasing rate of TCP transmitting windows. DSVR can reach the steady state rapidly because its configuration of the slow-start threshold is based on the bandwidth estimation, and thus the lost packages will be limited and the entrance of congestion avoidance stage will not be too early. Simulation result proves that this alogrithm can avoid the loss of data packets, reach the steady state quickly, and improve TCP throughput in the complex network. This algorithm is robust to the bottleneck buffer, adaptable to WEB service, and compatible with the present TCP protocol. It is simple and practical in that it only modifies the sender of TCP.

Key words: congestion control, slow-start, DSVR