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For some reason this particular topic is kicking my butt tonight. I am downloading the 802.3 to see if I can dig through and find the actual documentation, but a few quick searches on here and I can't seem to find the particular information I am looking for.

As a preface to this question, I will also note that my knowledge of POE in an enterprise world so far is "does it need to be on?" "Is it on?" "If not turn it on" kind of newbie status.

While reading through the section on POE in the CWNA book I came across a section that states "If a device does not respond to the detection signature, the PSE will withhold power." While taking practice test A I get the question, "What is the maximum amount of Watts a PD device can draw from an 802.3 Clause 33 PSE if the PD does not provide a recognized classification signature?" and the answer is not 0. The explaination for the correct answer of 12.95 says that a Class 0 is default, giving .44W to 12.95W.

Am I reading too much into this? I understand that the CWNA book is not meant to be the holy grail of 802.3 information, but it seems very conflicted to me.

Also if Class 0 is default, why is the .44W not the default. It seems to me that if it is unrecognized and is prepared to run on say 1.7W for arguments sake, that tossing it a 12.95W by default could be a pretty bad thing.

Does anyone have a good resource, other than perhaps the 802.3 ratified that I am downloading now that can truely explain this? Thanks in advance for any help.