Google outlines its Jupiter data center network architecture

Google's "Jupiter" data center network combines optical circuit switching (OCS) and wave division multiplexing (WDM) technology to ensure uniform, arbitrary communication among tens of thousands of servers at 100s of Gbps of bandwidth with sub-100us latency, according to a blog post by Amin Vahdat, Google's VP/GM Systems and Services Infrastructure.

Jupiter currently supports more than 6Pb/sec of data center bandwidth. 

The data center network architecture is described in a paper presented at SIGCOMM 2022 called "Jupiter Evolving: Transforming Google's Datacenter Network via Optical Circuit Switches and Software-Defined Networking."

Notably, Google developed its own Optical Circuit Switching (OCS) technology that maps an optical fiber input port to an output port dynamically through two sets of micro-electromechanical systems (MEMS) mirrors. These can be rotated in two dimensions to create arbitrary port-to-port mappings.

A rack with 8 OCS switches enables arbitrary logical topologies between data center packet switches. OCS simply reflects light from an input port to an output port without packet routing or heading parsing.

An SDN control plane seamlessly orchestrate thousands of dependent and independent operations.

Amin's blog post: https://cloud.google.com/blog/topics/systems/the-evolution-of-googles-jupiter-data-center-network

Google's SIGGCOM paper: https://research.google/pubs/pub51587/