Meru AP 832e / HP 2920 POE Issue

[flyinghaggis]

We're recently purchased a Meru Wi-Fi system and are experiencing PoE issues when trying to connect them to our network switches (HP 2920's). For some reason the switches seem to be allocating the PoE wattage to a single port rather than displaying it across all the switch ports. For example if we plug in 3-4 APs (which use about 7 watts each) the switch will fail with a PoE error after connecting the fourth one due to, what it thinks, is a lack of available power. I believe this happens as each individual port can only provide up to 25w IIRC. The switch itself should be good for up to 370w of PoE juice though?

 

We've tried connecting other PoE devices (HP mini-switches, Ruckus APs) and they've all worked as expected. This problem only occurs with our Meru 832 AP's. The only unusual thing is that we haven't received the controller yet so I don't know if that being online would prevent the issue occurring?

 

Has anyone else experienced the same issue or similar issues?

Edited May 6, 2014 by flyinghaggis

[Michael]

The HP 2920 supports PoE and PoE+ across all ports. Have you tried a firmware upgrade on the switch?

[flyinghaggis]

The HP 2920 supports PoE and PoE+ across all ports. Have you tried a firmware upgrade on the switch?

 

Yes, the switches should work ok with both Poe levels! We've updated them to the latest version of the firmware but it hasn't made any difference unfortunately.

[m25man]

Out of the box I'm pretty certain the 2920 only supports standard 802.af 12w per port.

You have to program the ports that you need to support 802.at 25w per port.

Check out the HP PoE deployment guide.

I've also seen these switches fried when over loaded with too many PTZ cameras so be cautious when setting up the PoE levels.

[flyinghaggis]

We've installed pre-release firmware from HP as a test to resolve it. The ports are now reporting the correct power usage and it worked to begin with for a while but the switch threw a PoE error, and stopped powering the APs, after running for a couple of hours so there's still some kind of issue there.

 

Back to HP/Meru tech support to see if they can advise I guess.

[m25man]

Is the cabling good?

Again the cabling between switch and end device maybe damaged.

 

All my testers have PoE validation so you can start with a cable test with Class1 and ramp the load up to test.

 

CCA cable is another pitfall to watch out for.

[flyinghaggis]

On further investigation the issue seems to relate to the fact we're using shielded CAT6a STP cabling with the Meru AP's which is causing issues when using power over Ethernet to drive them. It works OK with the unshielded CAT5/6a UTP cabling elsewhere in the school. Edited May 23, 2014 by flyinghaggis