Wireless Access

I'm trying to solve an issue in my network where users are being disconnected from the 5GHz SSID. Most times toggling their wifi on and off will reconnect them, other times they will have to join the 2.4 GHz network for a short-period then try reconnecting later in the day. 

What are some things I should check on to remedy this issue? There seems to be no clear sign of when it happens or how long it happens for, but the issue only affects a random group of laptops – usually about 5-7 laptops. I have not narrowed down a commonality between the users. 

All 7 APs are IAP 325s. 

Controller is Aruba 7005-US running version 6.5.0.3

I've attached a screenshot of the Usage dashboard, let me know if other screenshots would be helpful. 

Thank you!

Attachment(s)

ArubaNetworkSS.pdf   130 KB 1 version

Are those all Windows laptops?

Most of the fleet consists of Mac computers. We might have 3 to 4 Windows laptops. Then we have 5 conference rooms each equipped with an Asus Chromebox. 

I haven't checked any release notes... however we ran into problems with 300 series APs on 6.5. ArubaOS Driver issues caused the AP to register high channel utilization on DFS channels when ARM scanning. Symptoms varied from clients occasionally dropping of 5GHz to the AP failing to transmit most of its beacons.

Check the channel utilization on your controller and see if there's anything suspicious there.

Hey Matthew,

What should I be looking for here?

I do notice there are some 'poor' quality radios with Channel Quality as low as 63. Does this confirm what my users are experiencing? What changes can I make to improve those ratings? (screenshot attached)

This doesn't look related to the issue I encountered. At first glance, I'd take a look at why you have high channel utilization on 2.4GHz for some APs. Very high retransmit rates will likely result in poor performance. If your mac clients are choosing 2.4GHz that's possibly a problem with 5GHz coverage. Clientmatch will try to move 5GHz clients over. If a client has associated at 2.4GHz, the clientmatch process can result in periodic disconnections and a generally poor user experience. The solution is to fix the RF issue.

I can confirm folks are selecting the 2.4GHz because of the poor signal quality/coverage from the 5GHz. Do you have suggestions on fixing the RF issue? 

That comes down to AP placement and possibly requires another AP. ARM has set your g radio power levels fairly low and your a radio power to likely the maximum you've allowed. It's likely the best solution is another AP in the area your clients are struggling to connect to 5GHz, and disable the g radio on this AP.

You could try increasing the power levels of you 5GHz radios to 21, depending on your regulatory domain. In order to maintain compliance with maximum permissible power levels once APs got up to four radio chains, the power output calculation was changed. Where we would run the 5GHz radios in an 802.11n AP at 18, with 802.11ac (200 series up) I've found 21 is effectively the same power level.

That said, increasing power is rarely the solution to a problem like this.

Sorry for the delayed response, Matthew. 

The trouble with this is, we're seeing the issue throughout the entire office. We have three separate rooms with users reporting similar issues. Given this information is your proposed solution still the same? Should I add an additional AP (with the 'g' radio disabled) in each room?

Rooms A, B, C

A: [large room, 2 APs already installed]: Occasional drops from 5GHz, some devices are unable to connect to 5GHz. 

B: [medium-size, 1 AP already installed]: Occasional drops from 5GHz. Devices are usually able to reconnect after toggling wifi off/on. 

C: [large-size, 1 AP already installed]: No reported drops. Some devices are unable to connect to 5GHz. 

Maybe. You need to identify why 5GHz capable clients are not able to make or maintain a connection your APs on the 5GHz radio. There are too many possible variables, one of which being low signal strength.

WiFi Explorer Pro is a good tool for MacOS that will help you understand how your Mac clients are 'seeing' the RF environment.