Rethinking Ethernet For The AI Scale-Up Era: Inside ESUN

Every generation of AI infrastructure has redefined what “the network” means. In today’s training clusters — scaling from hundreds to hundreds of thousands of accelerators — the interconnect is no longer a supporting actor. It has become a first-order determinant of system throughput, utilization, and cost per token. Accelerators inside these systems don’t just move data; they synchronize on it, step after step. When even a small fraction of that traffic is late, expensive compute sits idle wait