Power Over Ethernet Interoperability Guide

General Philosophy in Interpreting the AT Standard

We will try not to get too pedantic about what a given region or term should or should not be called. Because, even in the AT standard, there is some confusion on the regions, as discussed shortly. Instead, we will focus on what the AT standard seems to say or imply in terms of recommended and/or mandated PSE behavior.

In general, we should always attempt to resolve any behavioral ambiguities on a commonsense basis if necessary, keeping uppermost in our minds the basic engineering intent of the standards. Expressed from the viewpoint of the PSE, this basic intent is summarized as follows:

1.  To protect non-PoE devices and/or terminations from damage (typically due to higher voltage than they ...