The Data Center Network L1 Switch Protocol

Chuck Thacker et al. have proposed a data center network design using FPGAs to implement the switching infrastructure. Inside each switch, the design uses time slot circuit switching of data cells via a distributed crossbar in the data plane and best effort forwarding of control messages via a high-speed ring in the control plane. The goal is to produce a system with minimum total complexity. Existing networks are extremely complex, have many different failure modes, and are difficult to scale out to the size of a large data center.

The design fits in the context of a data center built in shipping containers. Each container holds a large number of servers and L0 switches, and holds two, top-level L1 switches, called A and B. Cables are run between all the containers to form a complete interconnection graph of the A L1 switches and likewise for the B L1 switches.

This paper presents a TLA+ specification of the L1 switch infrastructure.