Recommendation ITU-T J.216 defines the second generation of headend architectures for high-speed data-over-cable systems. The second-generation of headend architecture introduces a number of new features that build upon what was present in previous Cabinet DOCSIS Recommendations ITU-T J.223.1 and ITU-T J.223.2. This Recommendation includes key new features for the CMC III device (also known as the remote-PHY device). NOTE - The structure and content of this Recommendation have been organized for ease of use through direct reference to the original source material, based on the recognition of CableLabs by ITU as an ITU-T A.5 organization (https://www.itu.int/en/ITU-T/extcoop/Pages/sdo.aspx).