부산대학교 도서관

This paper generalizes the TCP Vegas congestion avoidance mechanism and proposes a model to use accumulation, buffered packets of a flow inside network routers, as a congestion measure on which a family of congestion control schemes can be derived. We call this model accumulation-based congestion control (ACC). We use a bit-by-bit fluid model to define the accumulation concept and develop a general control algorithm, which includes a set of control policies. The new prove its proportional fairness and global stability. The ACC model serves as a reference for packet network implementations. We show that TCP Vegas is one possible scheme, which fits into the ACC model. It is well known that Vegas suffer from round trip propagation delay estimation error and reverse path queuing delay. We therefore design a new scheme called Monaco, which solves these problems by employing an out-of-band receiver-based accumulation estimator, with minimal support from network routers. Analysis and simulations comparisons between Vegas and Monaco demonstrate the effectiveness of the Monaco accumulation estimator. We use ns-2 simulations to show that the static and dynamic performance of Monaco matches the theoretic results. One key issue regarding the ACC model in general, i.e., the scalability of router buffer requirement, is discussed.