An enhanced slow-start mechanism for TCP Vegas

Abstract

In this article, we present a new slow-start variant, which improves the throughput of TCP Vegas, we call this new mechanism Gallop-Vegas which quickly ramps up to the available bandwidth and reduces the burstiness during the slow-start phase. Since TCP (Transmission Control Protocol) is known to send bursts of packets during its slow-start phase due to the fast increase of window size and the ACK-clock based transmission. This phenomenon causes TCP Vegas to change from slow-start phase to congestion-avoidance phase too early in the large BDP (bandwidth-delay product) links. Therefore, in Gallop-Vegas, we increase the congestion window size with a rate between exponential growth and linear growth during slow-start phase. Our extensive simulation results show that GallopVegas significantly improves the performance during the slow-start phase. Furthermore, it is implementation feasible because only sending part needs to be modified.