Wireless 9971 Phones dropping

[dmurech0488]

We are having problems with out 9971 phones dropping off the wireless network.  Some of the times it is during a call and some of the time not.  The phones will re-register at times but in more extreme cases actually reboot.  We have a SSID set up that uses EAP-FAST and CCKM.  The deployment guide recommendations have almost been followed to the letter.  We did need to disable CAC as it was seeming to cause other issues that would clear up once disabled.

Please ask any questions that you have and I will try to get answers.  We have a TAC case open.  If the answer comes from them I will be sure to share.

Controller version 8.1.131.0

AP model 3700i (running in flexconect mode)

controller version - virtual controller

[Leo Laohoo]

We are having problems with out 9971 phones dropping off the wireless network. 

What firmware are the 9971 running on?  And this is happening to nearly all the 9971 in that office, right? 

The phones will re-register at times but in more extreme cases actually reboot.

How are they powered up?  Power cube or power injector?

[dmurech0488]

The phones are mostly running 9.4.2SR2-2, some are running 9.4.2SR1-2 and 9.4.2.13

Some are also running bridge mode.

We have not been able to tie the issues to any one difference on the phones.

They are getting power from a brick, no PoE.

We have some phones that have more problems than others.

A survey was performed and RSSI and SNR on devices that drop are typically around -50s and 40s, respectively.

[Leo Laohoo]

If web access is enabled on the phone(s), I'd say go into the phones and look at the logs.  

I've got a strange feeling the phones are not "rebooting" but they are actually crashing.