BUG: CSCud65237 - IMPACTING ASCOM 802.11N HANDSET

I received 2 emails from colleagues who were hit by this bug while using the Ascom i62. 

Apparently there is a BA ack issue, as noted in the bug. Its not clear if this is only impacting Ascom as the bug id references 802.11n handsets. I asked for frame captures and will post the result when I have them. 

CSCud65237 Bug Details

Encryption key corruption on BA ack with wrong ID
Symptom: Voice disruption after roaming Conditions: Third party 11n phone This is triggered by wrong TID sent on Block ACK by client. AP is incorrectly handling the invalid frame Workaround: roam to another AP	Status   Open  (More)  Severity   2 - severe  Last Modified   In Last 3 Days  Product   Cisco IOS software  Technology   Wireless, LAN (WLAN)  1st Found-In   7.0(230.0) 7.4(1.54)  Component(s)   ap-ampdu

Update on Tuesday, December 25, 2012 at 11:25AM by George

A follow up to this blog post: There is a TID issue which is the result of a bug in the Ascom phone while using 802.11n. Cisco has modified code and Ascom is working on a fix. Another work around is to disable 802.11n on the infrastructure.   

Comments

[Leo Laohoo]

The best option to bypass this fault with the ASCOM firmware is to disable 802.11n from the phone.

[Alex Moore]

We are having this exact issue with Nortel 8440 phones. The audio becomes 1-way and pings to the phone drop until it roams to a new AP. Disabling the N capability on the phone appears to have resolved it for now.

[Leo Laohoo]

Bug ID CSCud65237 is now considered as "Resolved" with the 7.0.240.0 (30 January 2013).

Release Notes:
http://www.cisco.com/en/US/docs/wireless/controller/release/notes/crn7_0_240_0.html

[Mark]

I have deployed the 7.0.240.0 code to resolve this issue and so far it looks like it has. Anyone else got any feedback in terms of having had the issue and it now being resolved?

Alex - you're right in saying that this bug is cleared when you roam.

[Leo Laohoo]

Mark - This fix is a two-part.

Cisco fixes the buffer overflow with the release of 7.0.240.0.

ASCOM is suppose to release a code as well. As far as I was told (accuracy is unknown), but ASCOM is still "beta testing" their firmware.

The best bet is to disable 802.11n on the ASCOM phones and upgrade the firmware to 7.0.240.0.

[Leo Laohoo]

Folks,

The Bug Toolkit has been updated with more information and the manufacturer's name has been mentioned. There's also more information about which firmware/autonomous IOS has rectified the issue. And here they are:

Controller-Based firmware:

7.0(236.8), 7.2(110.16), 7.3(101.204), 7.3(112.0), 7.4(100.11), 8.0(49.8), 8.0(50.35)

Autonomous IOS:

12.4(23c)JA7 & 15.2(2)JA1