802.11g NIC w/ on board TKIP (and possibly AES) support

[Sam Leffler]

Parv wrote:
> Currently i am using FreeBSD 6-STABLE (Feb 3 2005) w/ iwi-firmware
> port for Intel 2200bg mini PCI card (along w/ wlan_tkip module) ...
> 
>   iwi0 at pci2:2:0:  class=0x028000 card=0x27118086 chip=0x42208086 rev=0x05 hdr=0x00
>       vendor   = 'Intel Corporation'
>       device   = 'PRO/Wireless 2200BG Network Connection'
>       class    = network
> 
> 
> .. and it seems that hardware TKIP encryption support is missing ...
> 
>   iwi0: ieee80211_crypto_newkey: no h/w support for cipher TKIP, falling back to s/w
>   iwi0: ieee80211_crypto_newkey: no h/w support for TKIP MIC, falling back to s/w
> 
> 
> ... is that right, or is that driver that causes the above messages,
> by virtue of being unable to "somehow turn on" hardware TKIP
> encryption?

That is corect, the driver does not have support for h/w crypto.  But do 
you actually notice a performane hit in practice?  The intel maintainers 
of the linux driver recently committed changes to their driver to 
disable h/w crypto support by default.  I didn't see an explanation for why.

> 
> 
> I am interested in a wireless NIC (802.11g band) which has on board
> support to deal directly w/ TKIP, and possibly AES (so that my laptop
> does not get very hot while during use of wireless connection).  Can
> anybody verify if Netgear WG111T has such support?

Heat indicates the card is running a lot; this is separate from doing 
crypto in h/w (which likely will draw even more power).  The iwi cards 
do support power save operation in which the firmware will power down 
parts of the card when not active.  However in my testing this behaves 
horribly.  With the 2.40 firmware operating in sta mode I observed a 
2915 card come out of power save mode for every beacon.  It does this by 
sending two null data frames to the ap; one to tell it that it's now 
operating on full power and then another, after the beacon, to tell it 
that it's going back to sleep.  This may help keep the power draw low 
(though it's hard to believe) but will load your wireless network 
(imagine a bunch of stations operating in this way).  I monitored the 
linux driver to make sure this wasn't a bug in my code and saw the same 
thing.

As to the netgear card, all current Atheros-based cards do h/w crypto 
and the driver uses it.

	Sam