CODE TCP: A competitive delay-based TCP

TCP Vegas is a well-known delay-based congestion control mechanism. Studies have indicated that TCP Vegas outperforms TCP Reno in many aspects. However, Reno currently remains the most widely deployed TCP variant in the Internet. This is mainly because of the incompatibility of Vegas with Reno. The performance of Vegas is generally mediocre in environments where it coexists with Reno. Hence, there exists no incentive for operating systems to adopt Vegas as the default transport layer protocol. In this study, we propose a new variant of Vegas called COmpetitive DElay-based TCP (CODE TCP). This variant is compatible with Reno and it can obtain a fair share of network resources. CODE is a sender-sided modification and hence it can be implemented solely at the end host. Simulations and experiments confirm that CODE has better fairness characteristics in network environments in which it coexists with Reno while retaining the good features of Vegas.