This Recommendation specifies the detailed protocols and procedure flows that implement the reference points of the mobile/multi-access content delivery network (MEC-CDN). It defines the protocols between the MEC-CDN system and service/content platforms, between MEC-CDN nodes and MEC management, and among internal MEC-CDN nodes. The Recommendation also provides optional protocols that allow interoperability with other network elements that wish to access the network capabilities exposed by the MEC-CDN system.. With this Recommendation, protocols are provided to support efficient content delivery through coordinated operation of the MEC-CDN system and its integration with external service ecosystems.