Version 6 (modified by jdishongh@…, 5 years ago) (diff)


Wireless issues with Intel Centrino cards and the IETF APs

If you are having issues using the IETF wireless networks, but it works if you use the ietf-hotel please read further.

Please try using the new SSID called "ietf-2.4ONLY". This may solve your problem.

If you continue to have problems please report this either by opening a ticket or visiting the help desk in the terminal room. See and for more information on getting help.


We have identified a compatibility issue with the Cisco APs and certain wireless cards. At this point, all clients affected have been using Intel Centrino 6xxx AGN cards (where xxx is 200,205,250,300,310, and possibly others).

The bug is fixed in some Cisco images and APs, but it does not appear to be fixed for the APs we are using here, or we have a new bug. We are actively working on this issue with Cisco and hope to get a fix soon.

In the meantime, we have implemented a workaround. We have disabled WMM (Wi-Fi Multimedia) on the 2.4Ghz radio only. We have done this only on this radio, and not on the 5Ghz radio as disabling this extension disables 802.11n and 802.11ac data rates, and disables MIMO multiple simultaneous streams, and will result in lower performance.

We have also implemented a new SSID, called "ietf-2.4ONLY" that will allow clients to select the 2.4Ghz radio.

Clients can also disable the 802.11n and ac data rates on their client card and they should be able to use any of our SSIDs on any radio. On Windows, this can be done by configuring the adapter properties and setting 802.11n mode to "Disabled".

It has been reported that on Windows, updating to driver version for the 6200 will fix this. Upgrading the Intel driver to the latest version should resolve the issue at least on the client NIC side. There is an exception to this, however. The 6200 and 6300 cards on Linux have a latest driver version of This driver is known not to work. The Windows drivers can be downloaded from and the Linux drivers from .