A network device includes a plurality of physical-media entities (PMEs), each corresponding to a distinct channel, to generate transmit signals based on transmit packets received over a media-independent interface. The network device also includes a channel-bonding sublayer to direct the transmit packets from the media-independent interface to respective PMEs of the plurality of PMEs. The channel-bonding sublayer has a substantially fixed delay between the media-independent interface and the plurality of PMEs for the transmit packets.