TCP Vegas vs. TCP Reno: Multiple connections with different round trip delays

摘要

TCP is well known to favor connections with small round trip times (RTT) over those with large RTTs. In the present paper, our objective is to quantify this "unfairness". We use fluid approximations to derive formulas for the throughput achieved by each connection under TCP-Reno as well as TCP-Vegas. We show that in TCP Reno, the fairness can be improved if the queuing delays are larger than the propagation delays. We also propose few enhancements to TCP-^sVegas which enable to reduce the effect of the number of connections and ensure better fairness.