Meru Wireless Problem - Random Disconnects

[jnick]

A year ago we implemented Meru's wireless solution (AP320's) across half of our campus. Ever since doing that, which replaced extreme equipment, our clients were HAPPY. No issues what-so-ever. Well, over the last couple of months, we rolled out Meru to the other half of campus using AP320i. Ever since we did this, we noticed that all of a sudden, mainly on the new deployment, we are having a bunch of connectivity issues. Mainly, clients fail to negotiate and connect the first time or randomly disconnect.

Our environment is as follows...we are a college campus using Cisco Edge Switches and Meru wireless. We have roughly 2500 students that can bring whatever device they want. Our faculty and staff are using Thinkpads, all within T510's or T520's. This is where we are seeing the largest issue....in our faculty/staff. The student's could be having issues but it's hard to say as unless the wireless is DOWN, they don't complain.

The T510's and T520's are all using Intel chipsets (6200 and 6205). Here is what we found:

One SSId in the air using both 2.4/5Ghz -> Connection issues as described
Turn off 2.4Ghz on SSID (running only 5ghz) -> No issues. Solid as can be
Turn off 5Ghz on SSID (running on 2.4) -> No issues, Solid as can be

Therefore, we cannot link it to either radios or interference on 2.4Ghz. The only time the issue is seen is when all bands are active and the clients driver is set to Auto on the wireless mode. Like wise, using Meru's feature-set, we are band-steering to 5Ghz, of course. We tried disabling this, which showed no improvement.

We also tried all Intel chipset drivers from 13.0 - 15.1, no change. One of my co-workers found, using Packet Fence as a means of reporting, that every 69 seconds, like clock work, packet fence shows the machine dropping and reconnecting.

Any thoughts or tests that we can try to try and pin-point this issue? The only "fix" we've found so far is splitting the 5/2.4Ghz bands onto their own SSIDs, putting two up in the air.

Thanks is advance!

 

[Grentz]

I would split the two bands as a best practice anyhow.

For your own staff devices, you can set preference rules via GPO to prefer the 5ghz or 2.4ghz bands when possible. It really eases management splitting the two and quite frankly you could even split it so that only staff can use the 5ghz (and fall back to 2.4ghz) while the students are forced on 2.4ghz. Ensuring your staff plenty of bandwidth.

 

[jnick]

That's what we used to do until management (who is no longer with us) forced us to combine SSIDs. I agree it is easier to split and it looks like that's what we are moving back to...it's just annoying me on what the problem could be!

I am intrigued by the GPO's though...however we've been fighting this battle... Computers will often times not have connection on bootup, thus making GPOs worthless since there's no link to download the policies LOL

 

[Grentz]

That is confusing and sounds like bigger issues in regards to GPOs. GPOs will update in the background even when the machines are just running. It is not something that only happens on boot.

 

[jnick]

True, it will update every 90 minutes...good point!