Towards a Bufferless Optical Internet

This paper investigates the relationship between buffer size and long-term average TCP performance in Dense Wavelength Division Multiplexing (DWDM) networks. By investigating TCP NewReno, the authors demonstrate that buffer requirements are related to the number of wavelength channels at a bottleneck. With sufficient wavelengths, high throughput can be obtained with a buffer of one packet per channel; furthermore, there may be situations where an entirely bufferless Optical Packet Switching (OPS) will become feasible. For this paper, they develop new evaluation tools. First, they propose a method based on a two-part analytical model, with a new "Open loop" component which approximates packet discarding in a bottleneck DWDM switch, and a "Closed loop" fixed point which reflects the impact of TCP.