A method of classification of power requirements in a power over Ethernet system, the method comprising: providing a first classification voltage for a first classification cycle time, the provided first classification voltage being within a classification voltage range defined by a lower classification voltage limit and upper classification voltage limit; measuring a first current flow responsive to the provided first classification voltage; subsequent to the first classification cycle time, providing a voltage outside of the classification voltage range for a classification indexing time; subsequent to the classification indexing time, providing a second classification voltage for a second classification cycle time, the provided second classification voltage being within the classification voltage range; measuring a second current flow responsive to the provided second classification voltage; determining a classification responsive to the measured first current flow and the measured second current flow; and allocating power responsive to the determined classification.