Describes the detected PD type on this port.
A value of legacy(1) - indicates that the PD is using a
capacitive signature, which is pre-IEEE standard.
A value of ieee8023af(2)- indicates that the PD is using a
resistive signature and is compliant with the IEEE Std 802.3af.
A value of other(3) - indicates that the PD type could not be
determined.
A value of ieee8023(4)- indicates that the PD is using a
resistive signature and is compliant with the IEEE Std 802.3af
and/or IEEE Std 802.3at specifications.
A value of ieee8023at(5)- indicates that the PD is using a
resistive signature and is compliant with the IEEE Std 802.3at.