tag:blogger.com,1999:blog-3993498847203183398.post1795488306183823342..comments2024-03-29T10:25:14.642+00:00Comments on RevK<sup>®</sup>'s ramblings: Unifi UAP-AC with 802.3af and 802.3at PoE switchesRevKhttp://www.blogger.com/profile/12369263214193333422noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-3993498847203183398.post-63316242453640139012014-06-12T00:36:16.733+01:002014-06-12T00:36:16.733+01:00Thanks for the heads up. I have a number of AP-AC...Thanks for the heads up. I have a number of AP-AC units in the field. Some network using the In-Line PoE+ injector, and some not. I have not had any problems with these units(as a some sites are fine without the PoE, until last night, it just kept crashing. I thought it was a PoE issue, thanks for your clarification.Anonymoushttps://www.blogger.com/profile/14732072663527529891noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-22415100501188288812014-05-31T20:44:59.208+01:002014-05-31T20:44:59.208+01:00That sounds familiar, I recall reading of another ...That sounds familiar, I recall reading of another PoE AP which had something like 3 radios, but could only power two of those from 802.3af. If the Unifi units rely on firmware powering something down to be inside the 15W limit, but the beta firmware fails to do that, it would explain the whole problem.<br /><br />Have you reported it to Unifi to see what they say? (For that matter, is there any other difference now you've switched to .3at, like better range or something that might fit with something having been enabled that wasn't working previously?)jas88https://www.blogger.com/profile/05563592458314214904noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-46981026315067560392014-05-30T12:54:40.316+01:002014-05-30T12:54:40.316+01:00Cisco APs have a similar issue, but behave correct...Cisco APs have a similar issue, but behave correctly - if the power is not enough, they will disable some or all of the radios until they are connected to a better supply. Can just sometimes be hard to spot why your new AP is up and running but not actually providing service, but that's our monitoring, not the system's fault.Matthew Newtonhttps://www.blogger.com/profile/11465897178674571675noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-79384761217813797642014-05-28T15:16:56.159+01:002014-05-28T15:16:56.159+01:00We had similar problems with Zyxel APs on Netgear ...We had similar problems with Zyxel APs on Netgear POE switches. We use rack-mount in-line injectors now instead.JJhttps://www.blogger.com/profile/15638774441452806449noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-90773640599043924852014-05-28T11:26:19.462+01:002014-05-28T11:26:19.462+01:00My understanding is that it works by the switch su...My understanding is that it works by the switch supplying power at around 20V with a 100mA current limit and then measuring the current consumption and working out the resistance. This resistance is used to indicate the power rating.<br /><br />Its optional however and I suspect if the current draw is outside of the range for 802.3af then the switch assumes class 0 (rather than only assuming class 0 is the power consumption is practically zero). That would mean that a 802.3af switch would always try and supply power anyway to a device requiring more than 15W and cutting off power if it does take too much.<br />Either way the AP might not be supporting power negotiation or if it does then it could be the actual standard which is causing it to partially work on 802.3af switches.Gareth Bladeshttps://www.blogger.com/profile/01109177395639328580noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-63844131380223173982014-05-28T00:05:33.169+01:002014-05-28T00:05:33.169+01:00Almost no equipment gets power negotiation right, ...Almost no equipment gets power negotiation right, most don't bother with it at all. At work we make devices which have USB connections and can supply no more than 500mA, you're supposed to negotiate if you want more. But no equipment does. We're exploring the options, but may have to resort to hardware that simply shuts down the power a little above 500mA. This is a battery powered device, we can't have other kit pulling arbitrary amounts of power.Owen Smithhttps://www.blogger.com/profile/00890951742186614705noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-83084174121100793612014-05-27T22:47:25.129+01:002014-05-27T22:47:25.129+01:00Most likely the AP I Would have thought.Most likely the AP I Would have thought.Dragonhttps://www.blogger.com/profile/00022860954210501938noreply@blogger.com