Problems staying connected - Dell Latitude ST (1535C Half MiniCard Atheros based wifi)

[chris.brunt]

I have some Dell Latitude ST Windows 7 tablets and I am having major problems getting them to stay connected to wifi. They have the Dell wireless branded 1535C pci-e half minicard, which is atheros based and is running the only and latest driver I can find (3.1.2.41)

The devices connect to wifi but stop working after about 30-60 seconds and you sometimes have to completely reboot the tablet to get it to connect again. Basically you notice network activity stops and you get a limited conectivity exclaimation mark on the wireless icon in the systray.

Cleanair 3502i AP + some 1142N

3750G PoE Switches

WISM1 running 7.0.116.0

At the moment I have gone back to a simple WPA2 AES PSK wlan. It was the same with 802.1x authentication.

This device is connecting flawlessly on my Netgear router at home which is a WPA2 AES dual band 2.4 5ghz 802.11n.

Debugs Attached.

Any ideas would be good.

[JroseTCMC]

I have to agree with Chris on this one. The problem is not faulty hardware as the WLAN card on ours works...just not on N connections. We have 10 of these all doing the same thing as well. We also had a similiar problem with our new E6520 models they were connecting and then dropping. The problem there was adriver update and they look to be working ok now. The problem here seems to be exactly the same symptoms and I have troubleshot it the same way only more and really seems to be isolated to the way in which the WLAN card talks to the AP.

Dell seems to be aware of this issue and told me yesterday that they are aware that an issue is ongoing with connection issues with the ST. He had me remove all Athero's software from the system, which I found a way to do without the system hanging. But as I expected it did not solve the issue. So it is not a problem with Athero's and Windows conflicting and causing the issue. Seems to be completely on the WLAN card drivers at this point. Which Dell also told me that they are working on a new driver for the ST and hope to have one in "a few weeks."

The only thing I have not tried is using a USB wireless to see if I can connect via N that way. That would completely isolate the issue to how that specific card communicates. Anyone else try this yet?

-Joshua Rose

Systems Support Tech

TCMC

[Thomas Enchelmeier]

As supposed, the change of the WLAN card didn't solve the problem. DELL advised to reinstall OS and drivers. Even this, be surprised, didn't bring the Latitude to stay connected. You wrote this problem exists only on N networks? I can tell you, it's also present in b/g network environment.

Just called again the DELL support. They want to test it in their lab and call me back tomorrow.

I'll keep you informed.

[robert.murdoch]

Another Dell ST user with this same problem. In my case. In very rare cases I am able to stay connected for hours. Most times I loose connection in 20-30 seconds. I thought configuring the wifi network settings (in windows network and sharing center click manage wireless networks then the problematic network's properties) to Automatically use my windows login fixed this, however, I'm still experiencing the issue with that setting.

[pccitcomms]

Just wanted to add my name to the hat.  Same problem with the same hardware. I have tried the suggestions here and on the dell link, with no change. Connects for 20-30 secs then drops and will not connect to any wireless device until a reboot.  This card works fine from home and connecting to a 877 router, but fails when using any controller based light weight access point.

[Thomas Enchelmeier]

After my last phone conversation with DELL they confirmed that this is a problem with the network cards in conjunction with the Cisco access points. DELL global support is working together with Cisco to solve that issue. There will be a new driver or firmware for the card and possibly for the AP (WLC). Thats my last info.

Best regards

Thomas

[becca1jane]

Any updates on this?  Our hospital wants to purchase 4 Latitude ST tablets - we are running 7.0.116.0 on our WISMs - with 1252 and 1142 APs.  Hoping to avoid the potential issues you all have been running into.

Thanks!

[George Stefanick]

If you purchase new, request the intel card for your build. The intel doesn't have a issue.

Sent from Cisco Technical Support iPhone App

[tomlukes]

I know if has been quite some time, but ran across this, as we are seeing the very same thing.   I have just discovered a very consistant pattern with this.    If we ping the device, we see high ping times.  From the device, we don't.    What I found was if the client had CCX 4 and Client E2E version was NOT supported (as yours shows in client detail), the issue existed.    If you have CCX 4 and Client E2E version WAS supported (Intel NICs), the issue was non-existent.   I confirmed this at least on at least 30 devices having each.      If the device had CCX 5, it did not need the E2E supported to work fine.

It is very early in my troubleshooting.  I have tried to disable Aironet Extensions on the controller without any change.   So I haven't nailed down the fix, but narrowing it down to devices that have that combination.

[Scott Fella]

Funny that this came up. Im going onsite to a customer that is having issues like this with various laptops and some with the newer intel cards. They would ping their gateway and have ping times in the 100's to 1000's and the pings would stop for a little and come back. These devices work fine in and environment with 4400's and 1142, but have issues with 5508's and 3600's. I'm going to load the newest 7.2 on monday and see if I can get figure this our next week. Client doesn't want to touch contractor laptops and doesn't feel like having to update drivers, etc is a fix:)

Sent from Cisco Technical Support iPad App

[tomlukes]

Please let me know what you find.  We are on 7.0.116.0 with 4400s and 5508s with 1242s, 3502s and 1142s.    I may an upgrade as well, if I can get a small enough of a location.

[Scott Fella]

I will... the 5508's were initially on 7.2.103.0, then we upgraded to 7.2.110.0 and Monday I'm hoping to upgrade to 7.2.111.3 to see if that helps.  This is the only site that I'm having issues with.  I have other clients running various codes with no issues, so we shall see.

Thanks,

Scott

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[jgillfeather]

Hi all,

did anyone come up with any results for this?  We've been advised by Dell that there is an unsupported version of the Atheros driver which works "most of the time", the exception appearing to be either in a secure Wi-Fi environment, or maybe just with Cisco WLC's.

Did upgrading the 5500 work?

regards,

Justin

[ewieder]

What allowed me to get them to even connect was to disable the Client Exclusion setting.  This allowed me to connect to all forms of authentication.

[jgillfeather]

Cheers Eddie, will give that a try.

Pretty sure that will mean we fail our next Pen test though...

[Scott Fella]

Some things that I have noticed also is the session timeouts.  Try to uncheck this and see if that helps... Try one thing at a time so you know if one thing works or not.  Pen test..... just enable it before they get there:)

Thanks,

Scott

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