What is the deal with PoE 24V? UBNT?

bug99

Pulling my weight
Joined
Dec 27, 2016
Messages
397
Reaction score
154
A short while ago I would have claimed that PoE was a 48Vdc injection/decoupling onto the twisted data lines of Ethernet wire. This technology fell under an IEEE standard (802.3af now at). Now i see a fair bit of 24v gear (cameras, routers, APs, bridges, switches), a lot of it from one company "Ubiquity Networks", which seems to make high quality stuff. However, almost none of their gear meets the IEEE standards, and i do not believe it is compatible, yet UL lets them sell it and burn stuff up, only modifying the name to passive PoE vs PoE or active PoE (really it should just be PoE and the standard number that it meets like 802.3at). What am i missing? It seems that this seemingly good quality company totally missed the standards boat and as of yet has not gotten on board, and for some reason gets UL listings. I am fine with it being passive to save money, it should then have no problem working over the full voltage range without negotiation, but that is not the case, they fry. I think Cisco missed the boat a while back, but they have long sense gotten on board.
 

nayr

IPCT Contributor
Joined
Jul 16, 2014
Messages
9,329
Reaction score
5,325
Location
Denver, CO
PoE is a generic term for Power over Ethernet.. 802.3af is the standard and Ubiquiti makes no claims about about it being standards compliant... anything can say its PoE, but it cant say its 802.3aX unless it actually is.

Ubiquiti is now in a tough spot because they cant make devices fully compliant with 802.3af while maintaining backwards compatibility with 24v UBNT PoE

Ubiquiti has been around for a good while, and there 24v PoE was needed at one point for high power access points before the 48v PoE+ spec was finalized.. at the time there hardware was more geared for WiSP use and not so much enterprise so the PoE variation was really no big deal.. but now there doing enterprise equipment with UniFi hardware and kinda shot them selves in the foot.

The solution is quite simple, buy some 48v Active PoE to 24v Passive PoE adapters.
 

bug99

Pulling my weight
Joined
Dec 27, 2016
Messages
397
Reaction score
154
Not ideal for sure. will be interested to see if they get it together. they still seem to violate the labeling as seen on the adapter. a deep dive is needed to reveal that the output is 18V vs the assumed 48V for the 802.3af indicated by the port label. If i were them, i would band-aid the old devices, rather than the newer complaint devices, but that is just me.

upload_2017-1-30_12-56-35.png
 

nayr

IPCT Contributor
Joined
Jul 16, 2014
Messages
9,329
Reaction score
5,325
Location
Denver, CO
im almost certain thats not the actual labeling on my adapters.. thats just a rendering take it with a grain of salt
 
Top