Enabling Compatibility Between TCP Reno and TCP Vegas

Despite research showing the superiority of TCP Vegas over TCP Reno, Reno is still the most widely deployed variant of TCP. This predicament is due primarily to the alleged incompatibility of Vegas with Reno. While Vegas in isolation performs better with respect to overall network utilization, stability, fairness, throughput and packet loss, and burstiness; its performance is generally mediocre in any environment where Reno connections exist. Hence, there exists no incentive for any operating system to adopt TCP Vegas. In this paper, we show that the accepted (default) configuration of Vegas is indeed incompatible with TCP Reno. However, with a careful analysis of how Reno and Vegas use buffer space in routers, Reno and Vegas can be compatible with one another if Vegas is configured properly. Furthermore, we show that overall network performance actually improves with the addition of properly configured Vegas flows competing head-to-head with Reno flows.