Switching the Optical Divide: Fundamental Challenges for Hybrid Electrical/Optical Datacenter Networks
Recent proposals to build hybrid electrical (packet-switched) and optical (circuit switched) data center interconnects promise to reduce the cost, complexity, and energy requirements of very large data center networks. Supporting realistic traffic patterns, however, exposes a number of unexpected and difficult challenges to actually deploying these systems "In the wild." In this paper, the authors explore several of these challenges, uncovered during a year of experience using hybrid interconnects. They discuss both the problems that must be addressed to make these interconnects truly useful, and the implications of these challenges on what solutions are likely to be ultimately feasible.