An apparatus comprises: a first clock; a receiver configured to: receive a first packet via a first channel corresponding to a first wavelength, and receive a third packet via a third channel corresponding to a third wavelength; and a processor coupled to the receiver and configured to: implement channel bonding using the first channel and the third channel, synchronize the first clock based on the first packet, and calculate a channel skew between the first channel and the third channel based on the first clock.