China Mobile China Mobile Huawei Technologies Huawei Technologies HKUST (Guangzhou) As is mentioned in draft [CCO PS & USECASE], the most obvious problem on why existing protocols cannot meet the high-performance requirements of collective communications is that these distributed applications are not co-designed with the underlying networking protocols. There is a semantic gap between inter-process message transportation and packet forwarding, which should be bridged by efficient mapping and optimization. This draft further presents the technical requirements on how the collective communication optimization should be designed, and makes some discussion and analysis on several related work.