Introducing Backpack: Our second-generation modular open switch

This post introduces Backpack, Meta's second-generation modular open switch platform, designed to support 100G data center requirements. It features a fully disaggregated architecture with switch elements, separation of data, control, and management planes, and an orthogonal direct chassis for improved signal integrity and thermal performance. Backpack utilizes FBOSS and OpenBMC for its networking stack and system management, and integrates BGP for routing with fabric cards acting as route reflectors. The post details the rigorous three-phase testing approach (engineering validation, design validation, and production validation) and highlights improvements made over the first-generation 6-pack switch, such as removing BGP Next Hop from ECMP groups and implementing port striping for better load balancing. It also emphasizes the importance of control and data plane monitoring using tools like Scuba and a new FIB monitor.