Congestion Control Without a Startup Phase

The traditional TCP congestion control scheme often yields limited performance due to its conservative Slow Start algorithm, which can require many round-trip times to reach an appropriate sending rate that well utilizes the available capacity. A number of techniques in the literature address this issue, but we offer a different approach that is simple yet blunt: allow TCPs to begin transmission at whatever rate they deem appropriate. We term this technique “Jump Start”. While Jump Start simply removes the traditional startup phase, the remainder of TCP’s congestion control algorithms (additiveincrease/multiplicative-decrease and timeout mechanism) remain intact. Our approach in this paper has two components. First, we attempt to understand the potential implications of removing TCP’s startup phase. Second, we step back and attempt to identify network characteristics and techniques that may make Jump Start amenable to real networks. This paper represents an initial exploration of these ideas.