[cisco-voip] POE with CAT3 cable

[Paul]

Somewhere in the intarwebs. . . .


2. 802.3af

802.3af refers to the point at which the 802.3 committee approved clause 33 (June 12th 2003)..  This clause
is entitled Data Terminal Equipment (DTE) Power via Media Dependent Interface
(MDI) and defines the characteristics of the Powered Device (PD) and the Power Sourcing
Equipment (PSE).  802.3af applies to the MDI interfaces 10BaseT, 100BaseT and 1000BaseT interfaces only
running on 100Ω balanced cabling.  The MDI interface also acts as a Powered Interface (PI).
In plain English this means that network devices (PD) may be powered, as well as communicate via the LAN interface (PI),
receiving this power from a LAN switch (endpoint PSE) or inline alternative (Midspan PSE).
You can download sections of the 802.3 standard at IEEE 802.3. 

The defined characteristics are as follows: 
	* Classification of devices based on their power requirements (PSE)
	* A power source to add power to the 100 Ω balanced cabling system (PSE)
	* The characteristics of a powered device's load on the power source and the structured cabling
	* A protocol allowing the detection of a powered device (PSE)
	* A method for scaling power back to the detect level when power is no longer required (PSE)
	* Supply of 48VDC and up to 350mA so that the power initiated does not exceed 15.4W and the power that is delivered
does not exceed 12.95W
	* Supported on Category 3, 5, 5e and 6 cable




________________________________
From: Voice Noob <voicenoob at gmail.com>
To: cisco-voip at puck.nether.net
Sent: Thursday, June 4, 2009 11:41:50 AM
Subject: [cisco-voip] POE with CAT3 cable


Can someone point me to a document to confirm if I can use
POE with a 7942 using CAT3 cable? I have outlined where the phone will work at
10mbs but it does not say anything on POE support.