Enabling a Bufferless Core Optical Network Using Edge-to-Edge Packet-Level FEC

To cope with the phenomenal growth of the Internet over the next decade, core networks are expected to scale to capacities of terabits-per-second and beyond. Increasing the role of optics for switching and transmission inside the core network seems to be the most promising way forward to accomplish this capacity scaling. Unfortunately, unlike electronic memory, it remains a formidable challenge to build even a few packets of integrated all-optical buffers. In this context, we envision a bufferless (or near-zero buffer) core optical network and make three contributions: First, we propose a novel edge-to-edge based packet-level forward error correction (FEC) scheme that combats packet loss in the bufferless core, and characterise the impact of FEC strength on loss at a single link. Second, we develop a global optimisation framework for multi-hop networks, and propose a heuristic algorithm that adjusts FEC strength to achieve fairness amongst the different single- and multi-hop flows. Finally, we evaluate the performance of our FEC scheme for realistic mixes of short- and long-lived TCP flows, and show that edge-to-edge packet-level FEC can be tuned to effectively mitigate contention losses in the core, thus opening the doors to bufferless optical networks in the near future.