From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf1-x133.google.com (mail-lf1-x133.google.com [IPv6:2a00:1450:4864:20::133]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id B3CB33B29E for ; Tue, 18 Sep 2018 20:07:12 -0400 (EDT) Received: by mail-lf1-x133.google.com with SMTP id z186-v6so3492112lfa.5 for ; Tue, 18 Sep 2018 17:07:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=sC8lGe/lbMC0vapU65o3XK6Od3DYlXMs3AZK8Mg70Dk=; b=K3b2IQaNP7Xs1m2pP9COCS8qWjSQlzzeIr0FFu2+lHsmaHope+QSPhVlnxhkt3gNmD m/TBvgSJMNVdmVFQgFISFmc5IfHM2ZorrCaQEWd4l2FRGSrJWn7RLmVolNEtInniKsB+ tQPGlLcPGxOrs9CGbGCSOidGj1x27yubNIkZuWgZrm3OLc8/Fts2B4vOpSH3K3zKfwc+ P/yKjqCrknlOP1WQCjzypLiF7jb78lspx5VWzJiGJdbeM1V/Nx+8EtSfTvbK9ub2B6c9 dgh5ZlD3E9ss/pCZ2zH6Yzm/DoKqp83qxzgnfWgUYPtuUQDX6aGkHLvIjxrEOxu7N02Q x1vw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=sC8lGe/lbMC0vapU65o3XK6Od3DYlXMs3AZK8Mg70Dk=; b=qBTFRb6zk/bCm2qoKxK3g6bPS/A2sl7DbNBGGD6g727s7ETOX4/LFBn6AOpgxtiCCy iiQeqi0yex3+P+K7U6VR1FpsgP+4DgA1wNnFxxBpwMFZJ+bWN9veofkgmjtwfoO84M7E HHtFenanl4RHjFZZlJpXRPeqrsfgWnY2yh6haByeTuH2AeyQhD6ikj+gIjkJqEvfdQi9 056pitcKhqk8hhJ8MrrqQ47zqiLnF3DkiCAmQP6ewp8Oa4vOdVOWgrFfplgbiq3nt02m +h33WA23vwWK9KM+dRaGl3ojQ/Gkr5M4/Ki5qhdjpQlZtxx6n1k0p95Ey8V0cZe0KmSt G08g== X-Gm-Message-State: APzg51DPMNw9/jIf6t3U+UIFjkQTQFNd/UhGUEj0G1TD52fh+V+YN2CX dXVYXlo7+cRfla0tZcHzLsw= X-Google-Smtp-Source: ANB0VdYFM6unAFeCNMsKBiv680o251LEFwhaX6bWEldVn8B7QAFv8IbR7inzCJXEb7RbKUnXxBYbaQ== X-Received: by 2002:a19:5911:: with SMTP id n17-v6mr22390716lfb.102.1537315631102; Tue, 18 Sep 2018 17:07:11 -0700 (PDT) Received: from jonathartonsmbp.lan (83-245-234-249-nat-p.elisa-mobile.fi. [83.245.234.249]) by smtp.gmail.com with ESMTPSA id i16-v6sm725025lfj.73.2018.09.18.17.07.10 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Sep 2018 17:07:10 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) From: Jonathan Morton In-Reply-To: <8736u6cpyu.wl-jch@irif.fr> Date: Wed, 19 Sep 2018 03:07:08 +0300 Cc: Dave Taht , Make-Wifi-fast , babel-users@lists.alioth.debian.org Content-Transfer-Encoding: quoted-printable Message-Id: References: <87efdqcs28.wl-jch@irif.fr> <8736u6cpyu.wl-jch@irif.fr> To: Juliusz Chroboczek X-Mailer: Apple Mail (2.3445.9.1) Subject: Re: [Make-wifi-fast] [Babel-users] reducing delays in wifi mcast queues 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: Wed, 19 Sep 2018 00:07:13 -0000 > On 19 Sep, 2018, at 3:04 am, Juliusz Chroboczek wrote: >=20 >> Recently I tried to deploy a few babel 1.8.2 nodes with the latest >> openwrt, which I had to back out rapidly because I was dropping so = many >> babel packets under contention. >=20 > That's interesting. Could I please see a log? >=20 >> A patch to universally enable babel ecn in net.c "solves" this = problem, >=20 > Interesting. AFAIK, ECN is only considered by AQM queues, so this = implies > there's a queue in the way that's dropping Babel packets. Perhaps = this > queue could be convinced to treat Babel packets specially without = having > to hack around it using ECN? Or perhaps, if we know which queue that = is, > we could modify Babel's packet scheduling to be more AQM friendly? I assume it's the make-wifi-fast logic, which has fq_codel baked into = the Linux wifi stack. That would react to congestion and ECN as = described. - Jonathan Morton