Ultra Ethernet 1.1 extends spec to scale-up networks and adds programmable congestion control

The Ultra Ethernet Consortium released UEC 1.1 on October 12, adding scale-up network support, in-network collectives and programmable congestion control. The update also introduces the Unified Local profile, the Unified Forwarding Header and Congestion Signaling.

• UEC 1.1 arrived on October 12; the 1.0 spec was published in June 2025
• The Unified Local profile cuts per-packet overhead for short accelerator interconnects
• CSIG adds a 4- or 8-byte tag carrying congestion data along the packet path
• In-Network Collectives (INC) can halve the bandwidth needed for large reductions