Date: Thu, 18 Jul 2013 08:59:29 -0700 From: Adrian Chadd <adrian@freebsd.org> To: freebsd-wireless@freebsd.org Subject: Re: high latency due to distant clients Message-ID: <CAJ-VmonT=PDLOXQpeyvCGwS3QPciUTJuB316nMAvAUzSfx7HEg@mail.gmail.com> In-Reply-To: <20130718155200.GA381@pintail.NGC004> References: <20130718155200.GA381@pintail.NGC004>
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Hi, I think I fixed this in -HEAD. -adrian On 18 July 2013 08:52, Petar Bogdanovic <petar@smokva.net> wrote: > Hi, > > for several years now, I've been running an ALIX-AP with a CM9 Atheros > 5212 card. The AP covers a whole house which has about 6 flats and the > average amount of active clients ranges from 10 to 15. > > Recently I noticed high latency when pinging the AP itself which happens > when distant clients (who knows where around the house---could be inside > or outside) seem to cause "longs" (long on-chip tx retries) and/or > "xretries" (tx failed 'cuz too many retries). > > The Rate, when talking to these distant clients, is usually below 11M > (sometimes as low as 1M) which is consistent with their low RSSI values > the AP is reporting. > > With high latency I mean continuous bursts of 500-1000ms instead of > 0.5ms so I wonder if this is normal. > > The software is slightly out of date and athstats is not completely in > sync with the kernel i'm using (therefore its not reporting some values): > > # uname -a > FreeBSD parrot.NGC004 8.1-RC2 FreeBSD 8.1-RC2 #2: Thu Aug 16 21:13:54 CEST 2012 > > # athstats -i ath0 > athstats: ath0: Invalid argument > athstats: ath0: Invalid argument > 3181606 data frames transmit > 45659 tx frames with an alternate rate > 568149 long on-chip tx retries > 19091 tx failed 'cuz too many retries > 0M current transmit rate > 25 tx stopped 'cuz no xmit buffer > 20922 tx frames with no ack marked > 3039151 tx frames with short preamble > 362335 rx failed 'cuz of bad CRC > 1181 rx failed 'cuz of PHY err > 315 OFDM restart > 866 CCK restart > 2 TDMA slot timing updates > -0/+0 TDMA slot adjust (usecs, smoothed) > 26135 TDMA tx failed 'cuz ACK required > -74 rx noise floor > 3070927 tx frames through raw api > 6299685 fast frames received > 1328215 fast frames flushed from staging q > 20835 ANI decrease noise immunity > 6593 ANI increased spur immunity > 121582 ANI decrease spur immunity > 160 ANI decreased first step level > 2 cumulative OFDM phy error count > 2 RTS without CTS > 1360093 beacons received > Antenna profile: > > Any ideas on how to avoid that? Of course I could buy better antennas > but it seems that, generally speaking, this shouldn't happen. > > Thanks, > > Petar Bogdanovic > _______________________________________________ > freebsd-wireless@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-wireless > To unsubscribe, send any mail to "freebsd-wireless-unsubscribe@freebsd.org"
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