DETOUR: A Large-Scale Non-blocking Optical Data Center Fabric

Abstract

Optical data center networks (DCNs) are attracting growing interest due to the technical strength compared to traditional electrical switching networks, which effectively eliminates the potential hotspot caused by over-subscription. However, the evolving traffics with high fan-out and various patterns pose new challenges to optical DCNs. Prior solutions are either hard to support high fan-out communications in large-scale or suffer from limited connections with low performance.In this paper we propose DETOUR, a large-scale non-blocking optical switching data center fabric. DETOUR composes of optical circuit switches (OCSes) and connects them in a 2D-Torus topology. It supports up to 729 racks and 69K+ ports with each OCS having 96 wavelengths. DETOUR utilizes a broadcast-and-select mechanism and enables signals optically forwarded to any dimension. Moreover, it realizes non-blocking by recursively adjusting conflict links between the diagonal forwarding OCSes. Our extensive evaluation results show that DETOUR delivers comparable high performance to a non-blocking optical switching fabric. It outperforms up to 2.14× higher throughput, and reduces 34% flow completion times (FCT) and 21% energy consumption compared with the state-of-the-art works.