Set to fullduplex(1) to operate in full duplex mode, port
will allow simultaneous transmit and receive which can
double its bandwidth.
Set to halfduplex(2) to operate in half duplex mode.
Set to autoNegotiate(3) to allow the switch to negoti-
ate with the other end of the connection.
The status of duplex mode on a port is available with
c2900PortDuplexStatus object.