A single hardware device (“unified NDR core”) that supports a narrowband digital return (NDR) channel for a plurality of remote PHY devices. The unified NDR core may be located within a cable headend. The unified NDR core comprises a single digital-to-analog converter (DAC) which converts digital payloads carried by digital packets received from the plurality of Remote PHY devices into a RF signal. The unified NDR core further comprises a transmitter for sending the RF signal to an Out-of-Band (OOB) Termination System. The unified NDR core supports a plurality of narrowband digital return (NDR) channels for the plurality of remote PHY devices.