I don't know what "system" power rails you're referring to, but you're right that UTP carries no power.
http://en.wikipedia.org/wiki/IEEE_802.3af[/QUOTE]
I don't believe that PoE techniques are what plugwash was referring to when he wrote "system power rails". I have a feeling that he was talking b*llocks.
Does anyone know the answer to this? Otherwise I'm gonna have to look it up.
It's a differential signal. Whether one core carries the inverse of another is a largely philosophical argument.
I must be being thick because I can't see the philosophical argument here.
Differential is term I'm quite happy with, and I agree that it describes the signal carried by each pair in UTP cable, but
inverse? I can see a reason for doing it, being to increase the signal to noise ratio on the wire, but I didn't know that this was a technique used with 10xyBASE-Tz.
And I still don't know...