Express Lane to Efficiency and Reliability: Multi-Dimensional Control in Meta’s Express Backbone Network#

Faisal Iqbal, Vitaly Neganov, et al. (Meta), Aditya Akella (UT Austin), Ying Zhang (Meta)

• Why: Meta's EBB is one of the largest WANs on earth, and this is the follow-up evolution under AI-era traffic pressure — useful as a reference point for how far you can push a mature multi-plane SDN WAN design before adding new control dimensions.
• What: An operational account of evolving EBB's control plane along two new dimensions beyond per-plane TE: Unequal Cost Multi-Path (UCMP) for cross-plane load balancing and Fast Re-Route (FRR) for rapid local failure detection/recovery — meeting AI-era efficiency and resiliency demands without fundamental architectural change.
• How: UCMP extends control across planes so traffic can be split unevenly across parallel planes for utilization; FRR adds per-device, time-slice control for sub-second failure handling. Both are described with design, implementation, and production results.
• Where applicable: Meta-specific production WAN, but the multi-dimensional control framing (global-across-planes + local-per-device + existing per-plane TE) is a clean conceptual model for any large multi-plane backbone. Real deployment experience, not simulation.