Buffer Management Schemes for Supporting TCP in Gigabit Routers With Per-Flow Queueing

(PREVIOUS TITLE: DESIGN CONSIDERATIONS FOR SUPPORTING TCP WITH PER-FLOW QUEUEING) Recently much research attention has been focused on the use of fair queueing schemes as a means for guaranteeing end-to-end delay bounds. Studies in this context have primarily been for non-feedback-controlled leaky bucket policed traffic. In this paper, we investigate the extent to which fair queueing (and its variants), in conjunction with appropriately tailored buffer management schemes, can be used to achieve the following goals for TCP traffic: 1) alleviate the inherent unfairness of TCP towards connections with ling round-trip times; 2) provide isolation when connections using different TCP versions share a bottleneck link; 3) provide protection from more aggressive traffic sources, misbehaving users or from other TCP connections in the case of reverse path congestion; 4) alleviate the effects of ACK compression in the presence of two-way traffic; 5) Prevent users experiencing ACK loss (which causes their traffic to be bursty) from significantly affecting other connections; 6) provide low latency to interactive connections which share a bottleneck with "greedy" connections without reducing overall link utilization. The paper proposes new buffer management schemes to be used in conjunction with fair queueing, so as to achieve the above goals for TCP, and compares the performance of the proposed schemes to the performance obtained using RED for packet dropping.