GXP 2000 and PoE Profiles

Did the PoE hardware change in later models of the GXP-2000.

I have several of these units, on one of them (one with an early hardware release), the PoE is negotiated as Class 2 (Maximum of 7 Watt, so 7 watt reserved in the switch). On all the other units, Class 0 gets negotiated (which is the default if the device doesn't negotiate a speed). This reserves 15.4 watt, (even though the devices never draw more than around 3.5).

Was this a downgrade in later versions of the design (cost reduction?).

There is still a reasonable amount of capacity on the switch, but if it starts looking tight, is there a way of altering the newer handsets to negotiate a different class?