ATIS Standard ATIS-0200003 provided initial use cases and requirements for Content Distribution Network (CDN) Interconnection between two CDN providers via Cache-based Unicast delivery method. ATIS Standard ATIS-0200004 developed use cases and requirements for content distribution via Multicast-based delivery. This ATIS Standard extends the use cases and requirements for an environment involving multiple CDN providers joining together to form a CDN Federation. The interconnection life cycle use cases and requirements developed in the previous two ATIS Standards are re-examined for the impact arising from a Federation of multiple CDN providers. Additional emphasis is placed on the interconnection domain functionality such that guidance on the eventual development of Network-Network Interconnect (NNI) architectures and supporting protocol requirements can be derived.