Intermittent dropouts Intel Centrino Advanced-N 6205

[chris.brunt]

We are having big problems just with this particular adapter in our environment. We are getting intermittent dropouts. The connection will freeze and stop responding to the point where you have to do a windows repair or restart the adapter to get it working again. You can be connected for a whole day with no issues or it could happen at random eg after 20 mins of being connected. Other devices in close proximity e.g. an intel 5100 and 5300 agn are working perfectly.

You get no indication that the connection has dropped and the adapter in the systray looks as if it is still transmitting packets but not recieving any. Cisco WCS troubleshoot indicates no problems. Events in the debug stop and dont start again until you do a repair on the machine.

Intel and Lenovo support have been really unhelpful (they basically don't want to know, apalling service), so now i am turning to Cisco just in case its a configuration issue, which i don't believe it is as we have no reported issues at all with other clients.

On the machine sides we have:

Lenovo x220 Tablet with Intel Centrino Advanced-N 6205 mini pci-e adapter.

Also happening with Fujitsu T730 tablets also with with Intel Centrino Advanced-N 6205 mini pci-e adapters

We have tried all intel driver versions from the latest 14.2.0.10 down to the OEM versions supplied.

they are running Windows XP SP3. We have also tried it with Windows 7 and get similar issues.

We are using Windows Wireless Zero Configuration, WPA2-AES with PEAP and machine (computer) authentication against Cisco ACS v5.2 talking to AD.

On the Wireless infrastructure side we have:

Cisco 1142N (-E-K9) APs connected to 3750G w/poe stacks

The controller is a 3750G-24-WS-50 model running version 7.0.116.0

managed by WCS.

The wireless has 20mhz channels on 1,6,11 on the 2.4ghz side (N is disabled) but we do have N enabled with 40mhz channels on the 5ghz with all UK country channels.

The machines connect at up to 300mb/s and signal quality is excellent. AP density is quite high in the room. DCA, TPC and Tx power control are enabled and set to automatic.

Can't think of more detail to include but I would appreciate any ideas anyone may have.

[nathanjscott]

Jeremy,

Here is the list I've seen from this post.  My specific scenario is using Cisco 5508's with 7.6.130.0 code:

• Disable MFP - I have done this, seems to have helped mitigate the issue
• Upgrade to latest driver on Intel site 15.13.0.2 - I have done this.  I also changed setting to High Roaming/High Power.
• Disable Rogue detection across AP's - I did this but i'm not sure it helped.
• Disable 802.11n on clients - I have not done this, there were to many, just suggested it to customer.
• Disable UAPSD on clients - this seems logical, it's a power save mechanism.  I have not done this, but suggested it as well.  Known bugs with this an Windows 8.
• Disable 40MHz channel width.  I have not done this.

These are suggestions I have seen.  I have only tested the first three and the results are positive at this point.  I'll keep you posted if I get more negative feedback from the customer.

Nate

[Jeremy Homan]

Nate,

Thanks a bunch! I've went ahead and done the following;

Disabled 802.11n
Disabled 40mhz channels
Set Roaming to Aggresive
Turned off any Power saving features
Upgrade driver to latest Intel driver

Tonight, I will set MFP to Disabled rather than Optional for the SSID.

We have a mixture of 5508s/2504s w/ 1131AGs and 1602s. We're also running 7.6.130.x code.

If this fixes my issue, I'll be sure to drink a bottle of scotch tonight and give away a few reddit golds.

Cheers!

[Jeremy Homan]

So, this morning, both of my clients had dropoffs.

I'm going to purchase a few of

http://www.amazon.com/Edimax-EW-7811Un-150Mbps-Raspberry-Supports/dp/B003MTTJOY/ref=sr_1_4?ie=UTF8&qid=1422369495&sr=8-4&keywords=usb+wireless+network+adapter#Ask

to see if the problem persists. If it doesn't, well, I'll be buying a bunch more.

:/

[George Stefanick]

If you are getting one disconnect for the entire day, I would say that is really good. Did you remove session timeout on the WLC?

Also know that little USB you picked only does 2.4 GHz. 

[Jeremy Homan]

We used to see 5-10 disconnects per client per day. Now it seems to happen once or twice, generally during peak load times it seems.

Yeah I know, at this point, I just want to verify/confirm that it IS indeed the Intel cards problem and not something on my backend.

Yeah, timeout is disabled on my prod wlan. I worked with Cisco a few months back to configure my WLAN to BP.

[jerry.resnick]

I have tried all of the suggested solutions and nothing would help to eliminate losing the connection again and yellow mark in system tray reappearing just in a minute or two after applying the fix. I was thinking that maybe my 6200 is broken. I still kept searching through google until I found the following link: http://bbone99.blogspot.cz/2010/12/how-to-solve-wifi-issue-on-thinkpad.html.

I was almost confident it would not help as I already had my laptop on Max Performance when Plugged in. But the author in this article mentioned to change both Plugged in and On battery options to Max Performance. I was always plugged in when expriencing the issue, so I did not think it could help, but I switched the On battery setting to Max Performance anyway per suggestion.

Guess what, no more dropouts or yellow warnings in tray. Everything seems to be working properly so far. 

[jerry.resnick]

Just a quick detail in case the link to the article will not work - this is about  Wireless Adapter Settings in Advanced Power Options. Both Plugged in and On battery Power Saving Options should be set to Max Performance.

[Scott Fella]

It might be good to make a single change and log it. This way you know what worked and what didn't. 

-Scott