On the advantages of lifetime and RTT classification schemes for TCP flows

We study classification schemes for TCP flows based on (a) lifetime (short vs. long lived flows) and (b) round-trip-time (RTT) attributes, as well as their combinations. The double objective served by the classification schemes is to satisfy the need for reduced response time, which is the primary concern of short lived flows, while at the same time ensuring fairness among long lived flows. The presented results indicate that the combined classification performs, under all tested case, comparably or better than RED and, as such, it is a reasonable alternative to the cumbersome task of properly parameterizing RED. In fact, the presented combined classification schemes achieve results equal or better than simple RED even when used in conjunction with DropTail queue management.