We numerically investigate and compare the network performance of FOSquare with Leaf-Spine under real traffic traces collected by running multiple applications (CG, MG, MILC, and MINI_MD) in an HPC infrastructure. Traditional electrical packet switches (EPS) rely on optical-electrical-optical (OEO) conversions, which result in high power consumption (tens of watts per port), significant latency (microsecond level), and frequent port rate upgrades. Optical Circuit Switches (OCS) have emerged as a solution. At the center of Lumentum's OCS platform is a technology with decades of proven deployment in optical networking:. This paper first summarizes the topologies and traffic characteristics in data centers and analyzes the reasons and importance of moving to optical switching. Recent techniques related to the optical switching, and main challenges limiting the practical deployments of optical switches in data. In this paper, we describe Apollo, to the best of our knowledge, the world's first large-scale production deployment of optical circuit switches (OCSes) for datacenter networking.
