How effective are one-bit protocols?

Congestion control lies at the heart of the general problem of traffic management in asynchronous transfer mode (ATM) networks. The primary function of congestion control is to ensure good throughput/delay trade-off performance. This paper presents a fundamental study on the performance limits of one-bit protocols for congestion control-implemented by many ATM switch vendors because of its low hardware requirements-using a new complexity theoretic framework. We derive the first known tight bounds on the buffer size required for one-bit protocols that fully utilize link capacity and guarantee no cell loss under network congestion. In particular, we show that any such one-bit protocol will result in cN²+O(dN), where N is the number of greedy sources in the network, d is the link delay, and the constant c is a parameter of the specific protocol