Flow control in the high-speed Thunder and Lightning ATM network

Advances in fiber-optic and VLSI technology are leading to the development of multi-gigabit wide-area networks based on asynchronous transfer mode (ATM). The Thunder and Lightning network project at the University of California, Santa Barbara, is building a high-speed ATM switch in which each link operates at 40 gigabits per second. The instant start protocol, developed for the Thunder and Lightning network, maximises throughput by allowing transmission to begin without a reservation while guaranteeing lossless communication even when the network cannot handle the initial rate of transmission. Instant start is able to provide this behavior with the use of first-in first-out (FIFO) buffers. This paper discusses the problems of exercising flow control in the high-speed Thunder and Lightning network and describes the techniques used by the instant start protocol to overcome them.