I have a dual booted Debian Etch (+WinXp) on dell 630c laptop.
Wifi is working but only seems to support up to 11g rate.

(HW is 11n capablen the WinXP side seen it can connect at 144Mb/s to an 11n AP)

upgraded to 2.6.24-etchnhalf.1-686 kernel (which supported a lot of the HW better than the older 2.6.18 etch kernel, infact a lot of parts of chipset were only recognised by 2.6.24)

as iwlwifi is supported in this kernel I only needed to install firmware-iwlwifi (right?):
so installed it (from Stable) : dpkg output:
ii firmware-iwlwifi 0.4+etchnhalf.1


Does this f/w support 11n on 4965 part or just 11g? If so anyone know where latest f/w for 11n operation is ? (or anything else I've done wrong)

lspci for Intel WiFi
0c:00.0 Network controller: Intel Corporation PRO/Wireless 4965 AG or AGN Network Connection (rev 61)

thanks

Since Intel is the sole source of firmware for this card, you could check their wireless site and see if you have the latest version. The other thing to consider is that wireless networks can only run at one speed, so if you have a g device on the network, everything will run at g speeds. Similarly if you put a b device on the network, everything slows down to b speeds.

downloaded latest 4965 driver from intellinuxwireless.org as suggested ( iwlwifi-4965-ucode-228.57.2.21.tgz) unpacked it to /lib/firmware/iwlwifi-4965-2.ucode. This doesn't seem to load correctly, see a few errors on boot , wlan0 doesn't come up, + a microcode error messg on halt, .

(previous version installed by the debian pkg was iwlwifi-4965-1.ucode)

Is kernel iwlwifi driver not up to date ? (but am at kernel 2.6.24 which isn't old)

So still at 11g speed.

The 11n AP has only 1 client (me) , so should work at 11n speed (the Windows driver (dual-boot) connects to this AP at 140Mb/s)

No, its not very old, but it still might be old enough so that it doesn't run the latest firmware. Or perhaps Debian has patched their kernel in a way that affects it.

About the only other thing I can think of is to try and manually set the speed with iwconfig and see if that gets you anywhere.

I got the same problem, and searching for solution.... All I can says is N is not supported so well... My config is (if that can help):
kernel: 2.6.25.18-0.2-pae
wifi card: Intel 4965AGN (0c:00.0 Network controller: Intel Corporation PRO/Wireless 4965 AG or AGN Network Connection (rev 61))

Using 802.11-G for the moment, 802.11-N is not working at all... I'm using opensuse 11... Any more ideas?