Data center optical data link layer architecture design and analysis

We design and analyze optical data link layer protocols for data center networks. Specifically, we compare the delay performance of an Ethernet only architecture and a hybrid flow architecture. The need of a new architecture becomes apparent as data centers scale to support increasing data volume. The bursty and large volume of data introduced by “elephant” flows, flows composed of 100s to 1000s of frames or more, can cause extreme congestion in the network. Scaling networking components in line rate is not sufficient. We show that data center traffic is more efficiently serviced with a hybrid flow architecture. We find the breakpoint when the traffic mix is such that the hybrid architecture delay is less than the Ethernet only architecture delay. As the ratio of elephant flows increase or as the size of elephant flows increase, the performance gains of the hybrid architecture compared to an Ethernet only architecture increases.