2015-01-14 17:41 GMT+01:00 Stefan Sperling <[email protected]> > OpenBSD's implementation of rate adaptation is basic. It's possible > that you'll see the AP sending data frames at less than 54Mbit/s under > normal conditions. You'll probably see better results with other OSs > since they have better tuned wifi stacks. It's an interesting problem > to look into but nobody is doing that right now.
Looks like I should start studying sources :-) I'll try to stick to OpenBSD, since I like how great it is documented and the ease of setting it up. > Try this on your AP: > > # tcpdump -n -i athn0 -y IEEE802_11_RADIO -vvv | grep data > > This shows a broadcast frame sent at 1 Mbit/s (which is normal for broadcast > since even old devices that only support 1 and 2 Mbit/s need to receive it): > > 17:19:44.890129 802.11 flags=42<PROTECTED>: data: 00:00:5e:00:01:01 sap 36 > > 01:00:5e:00:00:12 sap 37 I (s=64,r=48,R) len=80, <radiotap v0, 1Mbit/s, chan > 1, 11g> > > This shows a ping sent at 1 Mbit/s and the reply received at 2 Mbit/s: > > 2:18.085924 802.11 flags=42<PROTECTED>: data: fe:e1:ba:d0:6a:df sap 00 > > 00:13:02:03:a5:e7 sap 12 I (s=0,r=16,C) len=104, <radiotap v0, 1Mbit/s, chan > 1, 11g> > 17:22:18.091566 802.11 flags=41<PROTECTED>: data: 00:13:02:03:a5:e7 sap 00 > > fe:e1:ba:d0:6a:df sap 17 I (s=0,r=16,C) len=108, <radiotap v0, tsf > 502527151889, S > HORTPRE, 2Mbit/s, chan 1, 11g, sig 43dBm, antenna 1> > > During bulk data transfer I see rates of up to 18Mbit/s being used. > Do you see any higher rates than that, and if so, over long intervals > of time or just occasionally? I saw mostly 18Mbit/s during bulk data transfer. There were some 24Mbit and 36Mbit lines, but only occasionally. Need to find out what I'm looking at, to understand it. Since you have similar hardware, It looks like I've reached device's speed limit on current OpenBSD. Hope there will be 11n soon, AR9280 supports it.
