This Recommendation ITU-T J.223.2 defines the system architecture, the functional modules within the C-DOCSIS system, three different C-DOCSIS systems utilizing the functional modules, and the data and control interfaces between these modules for each of those systems. It also defines general device requirements for the different C-DOCSIS systems. With C-DOCSIS system, the modules that perform the physical layer and data link layer function can be deployed in the optical nodes of the HFC cable network. This Recommendation is technically identical to the [ETSI ES 203 312].