@techreport{li-moe-ep-communication-optimization-00, number = {draft-li-moe-ep-communication-optimization-00}, type = {Internet-Draft}, institution = {Internet Engineering Task Force}, publisher = {Internet Engineering Task Force}, note = {Work in Progress}, url = {https://datatracker.ietf.org/doc/draft-li-moe-ep-communication-optimization/00/}, author = {Zhiqiang Li and Zongpeng Du and Junjie Wang and Wei Cheng and Guoying Zhang and Xun Sun and Chunhao Zhao}, title = {{Communication Optimization for MoE Expert Parallelism in Distributed Training}}, pagetotal = 10, year = 2026, month = jul, day = 4, abstract = {This document describes a communication optimization mechanism for Mixture of Experts (MoE) Expert Parallelism (EP) in distributed training environments. It defines two core mechanisms: (1) an adaptive communication mode selection that dynamically chooses between Data-Centric and Expert-Centric All-to-All communication patterns based on a comparison of expert parameter size versus token data size, minimizing cross-node communication volume; (2) a priority-based co-scheduling strategy for All-to-All and AllReduce collective communications, combined with chunked transmission and in- network aggregation acceleration, to eliminate bandwidth contention and reduce overall training latency.}, }