Who Besides Ubiquiti Uses Non-Standard Poe?

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Brian Rhodes
•Oct 29, 2015
IPVMU Certified

In an IP networking class we talked about the potential problems that 'non standard PoE' can be.

Maybe the most familiar example of this is Ubiquiti, who has a PoE method that does not use (802.3af/at) 48 VDC, but (nonstandard) 24 VDC instead:

In the past, this has been an issue for unsuspecting PoE users unable to power using PSEs built to meet the 802.3af/at standard.

Where else in the market is non-standard PoE used? Any other brands or products to be aware of?

OB
Oðinn Burkni Helgason
•Oct 29, 2015
IPVMU Certified

I like Ubiquiti's access points, UniFi, and the server for that. Only thing I don't like about that is the fact they don't use standard PoE.

MM
Michael Miller
•Oct 29, 2015

Fluidmesh - Offer a 802.11AF adaptor

Mikrotik / routerboard

UBNT also offers a 802.11AF adaptor

(1)
BS
Bob Schenck
•Oct 30, 2015
IPVMU Certified

Very old Cisco. In their defense 802.11af wasn't a standard until 2003 and they were making the first POE equipment circa 2000. They switched over to 802.11af when it was ratified. You can find references to it in their documentation that refers to it as 'pre-standard' POE. Pretty rare to still see gear in the field that is old enough for it to be an issue. Their early IP phones used it.

Also Cisco now has gear that extends past 802.11at power limits and maxes out at 60W. But only the 60W max is non-standard, the switches can power regular 802.11at/af devices as well. Cisco calls it uPOE and I'd guess it will be the next POE standard fairly soon.

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DP
Donald Peters
•Nov 01, 2015
IPVMU Certified

Need to be a little careful with even 802.3at/af. Most equipment supports Mode B only (most common) but there is a bunch of Mode A injectors on the market. The difference is on which pins the power is supplied.

U
Undisclosed #2
•Nov 01, 2015
In reply to Donald Peters

Then those PD's (powered devices) are not technically PoE compliant. The standard states that the power supply gets to dictate the mode used, not the device being powered.

U
Undisclosed #1
•Nov 01, 2015
IPVMU Certified

Most equipment supports Mode B only (most common) but there is a bunch of Mode A injectors on the market

Disagree.

  1. All 802.3af compliant powered devices (i.e. cameras) must support both Mode A and Mode B.
  2. AFAIK, all POE injectors (midspans) are Mode B
  3. Most 802.3af compliant switches (endspans) are Mode A

A few observations.

  • Active PoE means 802.3af/at
  • Passive PoE is never 802.3af/at
  • Passive PoE can be supplied at different voltages, usually 12,24,48
  • Passive PoE is a misnomer in a way, as it is ALWAYS actively producing power.
  • A device requiring passive PoE will not be powered by an active (802.3af) PoE source.
  • A device which is designed to work with active PoE WILL be powered by a passive POE source IF the passive source supplies 48 volts and sufficient current, if the volts are 12 or 24 it MAY be powered by the source, depending on the device.
  • There is no passive PoE for gigabit ethernet and faster as there are no spare pairs anymore.
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David Johnson
•Nov 01, 2015

A pair of Avalan radios I used had 18VDC power supplys and injectors to send the power up the UTP.

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