From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.toke.dk (mail.toke.dk [52.28.52.200]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id C4B873B29E for ; Tue, 24 Apr 2018 17:32:56 -0400 (EDT) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=20161023; t=1524605575; bh=yR03e5SlNkHB6ffw9aGPbbtqzOc47+4L4n8124i00z0=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=T/5I14LYe9E0SsqSr9Cne0iOL6jzWJYWGS2PmJbXuV8X1RZ/H1pqL+lxppzr8QMzL pLcUNcMFwbRozmRxZGdch8wBVP5jc3sPIjZbh8QYAzblfrWT4wWTiyJ2aZjiz5cJ3U YXV5jBMH8dSp6Min1RMo+AR62HPLxwOnz3jo29JVPNG1fyNFhnz6MNXTerzX6g6NFC XNGPG2sAcf82G8Jn5bTNRqQ+Ave4xb+MZvmGFi37q1wuIe+zX3NaFDKkh9F2G+7Gke VPsVbsuJQTRFJXK0F7ffrqNLhHjlGRCCc0eG2NLQeulTMWRcYDRp+kPDelkxe8dPdP 5KhWrWVrvRoJA== To: Pete Heist Cc: make-wifi-fast@lists.bufferbloat.net In-Reply-To: References: <66BDCA6E-D7C4-4E76-8591-8FDC35B09EA3@eventide.io> <871sf495vs.fsf@toke.dk> <87po2o7lwb.fsf@toke.dk> <1BA3CECA-8C05-4E94-9E2A-1AEA3C2F20B3@eventide.io> <87k1sw7jxj.fsf@toke.dk> Date: Tue, 24 Apr 2018 23:32:54 +0200 X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <878t9c70jd.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Make-wifi-fast] mesh deployment with ath9k driver changes X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 Apr 2018 21:32:57 -0000 Pete Heist writes: >> On Apr 24, 2018, at 4:34 PM, Toke H=C3=B8iland-J=C3=B8rgensen wrote: >>=20 >> Not sure. You do get HOL blocking while a packet is retried, basically. >> And ath9k will keep trying way after it should have given up (up to 30 >> retries per packet). If you combine this with a lot of backoff for each >> transmission (which is also quite likely in a very congested setting), >> and I suppose it might be possible=E2=80=A6 > > So that means everyone else waits while a packet is sent and re-sent > to a station with a weak signal, for example? I see how that would > wreck the latency pretty quick with the number of stations connected, > plus channel contention with another repeater. It may be a much bigger > factor than bloat. Yup, exactly... > The physical situation is that there=E2=80=99s an AP on the roof of one c= abin, > and it=E2=80=99s surrounded by about 8 occupied cabins, each with 4 kids,= at > least one of which is probably curled up inside using Instagram or > YouTube. Signals and tx bitrates of the stations are below, for > interest. What I=E2=80=99ll try to find out is if it=E2=80=99s the activi= ties of one > or two devices that affect things the most, as it appears that mean > latency can suddenly go down to < 10ms and up to > 200ms because of > =E2=80=9Csomething"... Yeah, with those signal rates, there's going to be quite some pause when the slow stations try to transmit something... :/ -Toke