In <http://marc.info/?l=openbsd-misc&m=141928659802658&w=1> I asked
about the CPU overhead of doing wifi WPA2 crypto on a slow CPU.
I have received two very useful off-list replies, which I'll summarize
here for the archives:
One person has a very similar setup to the one I described (athn(4),
Atheros AR9220 radio), and wrote:
> My bottleneck seems to be the 802.11 stack of OpenBSD, it
> has some known performance issues: I get around 2MBps (16Mbit) data
> rates - the CPU could handle a lot more.
Another person reported good results with ral(4) and a Sparklan WMIR-200N
("Ralink RT2860/2850 chipset), which offloads the crypto to the hardware:
> over WPA2(PSK/AES/AES) it can push ~3MB/s at ~%33 cpu load, mostly
> interrupt handling.
with the caveat that
> Under OpenBSD 5.3 ral(4) caused kernel panics maybe twice a year.
> I never tracked down the cause but it seemed to occur when unfamiliar
> nodes joined the network and then only in certain circumstances.
ciao,
--
-- "Jonathan Thornburg [remove -animal to reply]"
<[email protected]>
Dept of Astronomy & IUCSS, Indiana University, Bloomington, Indiana, USA
"There was of course no way of knowing whether you were being watched
at any given moment. How often, or on what system, the Thought Police
plugged in on any individual wire was guesswork. It was even conceivable
that they watched everybody all the time." -- George Orwell, "1984"
