Mission Apollo: Landing Optical Circuit Switching at Datacenter Scale

Understand

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.

• We will first describe the infrastructure challenges and use cases that motivated optical switching inside datacenters.
• We then delve into the requirements of OCSes for datacenter applications: balancing cost, port count, switching time, and optical performance, which drive design choices and implementation details of our internally developed 3D MEMS-based OCS.
• To enable the Apollo optical switching layer, we employ circulators to realize bidirectional links through the OCS, effectively doubling the OCS radix.