Date: Tue, 9 Aug 2011 02:26:54 +0800 From: Adrian Chadd <adrian@freebsd.org> To: Lev Serebryakov <lev@serebryakov.spb.ru> Cc: freebsd-wireless@freebsd.org Subject: Re: Bad host-vased AP performace -- and qouple of questions about FreeBSD WiFi stack tuning Message-ID: <CAJ-VmonrRTRrvR9PWexxVzRzEGS9AW8%2BtZLZqUN1aZT9Uvoqqg@mail.gmail.com> In-Reply-To: <1832976164.20110808222108@serebryakov.spb.ru> References: <1151152206.20110808220720@serebryakov.spb.ru> <CAJ-VmomMh4uvyJGHHkGsi5_C4p3ZJjRwadmstRVe4BjY76QzoA@mail.gmail.com> <1832976164.20110808222108@serebryakov.spb.ru>
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2011/8/9 Lev Serebryakov <lev@serebryakov.spb.ru>: > Hello, Adrian. > You wrote 8 =C1=D7=C7=D5=D3=D4=C1 2011 =C7., 22:11:03: > >> Can you verify when "bad" and "good" performance occured? Can you >> narrow it down to FreeBSD versions in particular? > =9A I'm afraid, that will be difficult. I could try 8.2-RELEASE and > =9Aeven 8.0-RELEASE (but I'll need to build NanoBSD images for them). > =9AI'm sure, that 7-STABLE gives me 3.2MiB/s regularly, but noteboks > =9Awere changed from these times. I'll try to build 7-STABLE NanoBSD > =9Aimage, but it will need some more effort, as config files changes from > =9Athese times :) Hi, That's definitely required knowledge. 8.0-RELEASE is a good starting point. I'm afraid it's going to be difficult for me to narrow down what's changed without you doing a bit of legwork to find which kernel version(s) introduced the performance regression. Once we narrow that down, I'll fix it. :) Please keep everything else the same though, including the laptop. :) >> 2) not sure, it's late and I'm not knee-deep in the beacon frame >> format. But I bet it's ok? > =9AIt is "not accurate enough" :) Many APs, seen in my apartments, > =9Aannounce all speeds up to 54Mb :) But, of course, It is practically Ok= till > =9Aclients can connect on higher speeds. Hm, that's odd. The 11b rates should show up (1 -> 11), the rest are 11g rates. I can't think of why the AP wouldn't advertise all 11g rates, but then, I haven't gone digging in that code lately. >> 3) txpower is in dBm units, based on what the card is supposed to be >> putting out of the antenna socket, before antennas > =9AOk, so 30 means 1:1 (according to dBm definition) and means "full > =9Apower". Well, some cards "lie". You program in x dBm, you get x+constant dBm. That's how so high powered cards work - you program in some lower value that fits inside regulatory limits (say, 23dBm) and you then get (say) a +6 dBm boost no matter what you program in. So a 23 dBm txpower would equal 29dBm. 0dBm txpower would equal 6dBm. etc, etc. The only real way to know is a spectrum analyser. :) Adrian
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