MRC · Multipath Reliable Connection
An open RoCEv2 extension adding packet spray, trimming, and selective acknowledgment; already proven at frontier training scale, but training-first in scope rather than a general-purpose transport.
Current numbers
May 2026MRC released as an open OCP spec (OpenAI + AMD/Broadcom/Intel/Microsoft/NVIDIA): RoCEv2 extension with per-packet spray, SACK, optional trimming, PFC-off; production-proven at 50k–75k-GPU scale before publication
131,072GPUs in a two-tier fabric of 512×100G switches with each 800G NIC split into eight 100G planes (MRC consortium design; four-plane 4×200G and eight-plane 8×100G systems deployed)