Non-Scheduled Fabric

Overview

The Non-Scheduled Fabric (NSF) is Meta's AI scale-out network architecture for its largest gigawatt-scale clusters. Unlike the Disaggregated Scheduled Fabric (DSF), which uses centralized scheduling across the fabric, the NSF achieves lower latency by eliminating fabric-wide scheduling and instead relies on adaptive routing for load balancing across shallow-buffer Ethernet switches.

The NSF is built on 51T-class Ethernet switches (Minipack3 and Minipack3N) managed via FBOSS and OCP SAI. Meta's multi-ASIC strategy gives the NSF three switch options: Broadcom Tomahawk5 (Minipack3), Cisco Silicon One G200 (Kodiak3), and NVIDIA Spectrum-4 (Minipack3N).

At OCP Global Summit 2025, Meta also previewed a next-generation NSF network rack featuring liquid cooling, over 50 kW power draw, and high density — shown wired-up on the show floor but not yet in production.