Recommendation ITU-T L.1206 discusses multiple power supply interfaces to information and communication technology (ICT) equipment operated by dual power input feeds with combinations of standardized −48 V direct current (DC) or alternating current (AC) sources, or DC source up to 400 V interfaces. Operational voltage and interface characteristics are detailed in ITU-T Recommendations and European Telecommunications Standards Institute (ETSI) relevant standards. This Recommendation also includes some details on the power architecture within the ICT equipment between the ICT power interface and the ICT end load.