Abstract: Tuning an optical network unit (ONU) to an appropriate communication wavelength may be performed by initiating an activation procedure responsive to receiving a wavelength configuration message, and identifying an instruction in the wavelength configuration message to modify a present wavelength used by the network unit to a different wavelength. The process may also provide assigning an optical network unit identifier (ONU-ID) to the network unit, modifying the present wavelength to the different wavelength, and transmitting subsequent data messages from the network unit at the different wavelength.