Three-Stage Optical Circuit Switch Architectures for Intra-Datacenter Networking

To address the explosion in datacenter-related traffic, introducing optical circuit switches to datacenter networks is a promising solution given its low power consumption and control complexity. Among various switching technologies, a two-stage optical switch consisting of wavelength-routing switches and space switches can cost-effectively construct a high-port-count optical circuit switching system. However, its scalability is bounded due to the available bandwidth of the wavelength-routing switches and the power loss of the space switches. In this paper, we propose a novel optical circuit switch architecture based on three-stage switching networks that offers quite high port counts. Eight schemes can be used to realize this three-stage switch architecture. We evaluate these schemes comprehensively through computer simulations. We examine the maximum port count attainable by each architecture given the constraint of reasonable hardware cost. The results clarify that two of eight schemes are superior for constructing high-port-count switches. We fabricate parts of these two switch architectures and test them given the switch port count goals of 12288 × 12288 and 6144 × 6144. The computer simulations and transmission experiments confirm the feasibility of the proposed architectures.