Systems, devices, and techniques relating to network upgrade and protocol selection in wireline communication networks are described. A described network device includes ports to connect with destination devices over wireline transmission mediums, wireline transmission mediums respectively comprising at least one pair of wires for transmitting and receiving data; a packet processor configured to forward packets to and from the ports; first transceiver circuitry configured to communicate using an Ethernet protocol over at least a portion of the wireline transmission mediums; second transceiver circuitry configured to communicate using an OFDM broadband protocol over at least a portion of the wireline transmission mediums; and a controller. The controller is configured to determine a protocol used by a destination device connected with the network device, and for communications with the respective destination device, select among the first transceiver circuitry and the second transceiver circuitry based on the protocol used by the destination device.