Evolution of Meta's Edge and Backbone Networks#

Fredrik Korsbäck, Meta Platforms, Inc

• Why: The most direct window at this conference into hyperscaler physical backbone and DC fabric design — scaling strategy, ZR optics economics, and how AI traffic is reshaping both DC metro fabric and edge compute placement.
• What: How Meta grew the backbone >10X via two levers: scaling up (8-slot/288-port to 12-slot/432-port chassis; 288×400G to 288×800G interfaces) and scaling out (4→8 planes, multiple devices per plane). One site more than doubled platform capacity every year for 7 years (~192x cumulative). The Edge side is shifting toward an "Elastic Edge" with a global GPU footprint closer to users for uncacheable AI-generated content, plus a move away from route-server peering toward an automated bilateral peering portal.
• How: Two distinct backbones: EBB (DC-to-DC, IPv6-only, multi-plane, with Meta's own TE/routing software, deployed in DCs and midpoints) and CBB (DC-to-PoP, traditional IP/MPLS, single-plane). DC-metro architecture keeps paired DCs within 10km connected with 100,000s of 400G on single fiber pairs via frontend/backend switches; >10km AI backbone links run 10,000s of 800G ZR (ILA-free to 120–150km, 500km+ with ILAs) with optical protection switches. ZR pluggables (10–15W/plug) replace ~2kW transponders: a 1Pb midpoint scenario shrinks from 58 racks to 21 (400G-ZR) or 14 (800G-ZR).
• Where applicable: The scale numbers are Meta-specific, but the ZR rack/power math, DC-metro fiber strategy, and plane-scaling approach transfer to anyone building DC interconnect or long-haul fabric.