A network apparatus architecture is disclosed that includes one or more isolation circuits to accommodate a predetermined isolation voltage. Each isolation circuit enables an independent DC voltage to be selected along a network signaling path to accommodate different DC voltages of network circuits along the network signaling path. For example, DC isolation may be provided between a physical interface and a network circuit via one or more capacitors, optoelectronic isolators, coupled magnetic devices, or semiconductor devices. A network circuit may be powered by a power supply that is isolated from the rest of the network apparatus. The one or more isolation circuits and network circuits may be included in a system-on-chip, or application-specific integrated circuit.