Ultra Ethernet 1.1 Extends the Specification to Scale-Up Networks and Adds Programmable Congestion Control
Network World, Wednesday, October 14th, 2026
UEC 1.1 adds a lightweight transport for GPU scale-up networks and richer, programmable congestion control.
The Ultra Ethernet Consortium released UEC 1.1 on October 12, extending its AI and HPC Ethernet specification to scale-up networks that link accelerators inside a node.
Because scale-up traffic involves small messages at high packet rates, UEC 1.1 adds a simplified transport and options to reduce per-packet overhead, and the consortium is working with OCP on its ESUN specification.
The release also adds programmable congestion control, addressing limits in 1.0 such as single-bit ECN signals that indicate a queue is filling but not where or how badly.
The article explains how these mechanisms work.