From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-x732.google.com (mail-qk1-x732.google.com [IPv6:2607:f8b0:4864:20::732]) (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 6FAD83B29E; Tue, 18 Sep 2018 20:53:39 -0400 (EDT) Received: by mail-qk1-x732.google.com with SMTP id c13-v6so1912936qkm.4; Tue, 18 Sep 2018 17:53:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=o2syY4lCK5ZOxTJKtEpSnCT0/XeTyjTLeaTkGoyBL18=; b=LZ6oUXGCtpa9VKgnmsVulAqjXjP8klDUAn2lVpgkOAXkWauHRLCAomuewbJLjvtdLD tnKZRtw+3JcchQUyCWUcFlf6UkAy+3w4DnjXeMIXb1vF52QBbKpN1nA5fqodEwp2lZX+ /q6Jq0714cTweJiVnFUPCVPD51XSw0hRUo2r+NjevutyD1HcBhKwblTfXRCa7QkykPXx 8ZHYgtqo5CWXBh0CRiNlJzEYyUZ2RCCNrQhSLhZrp0kk8c46ImZzM6+pOULCAuh15sgt RaVGHKYR/PazRIS0Lqh3YS22PWx8fSQuFaBHApJxkuiO9HhYmmAa+8FWZXwd3NVVODoJ NXVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=o2syY4lCK5ZOxTJKtEpSnCT0/XeTyjTLeaTkGoyBL18=; b=UDG/FGzcYvNF/RMV+WSzyhRpCS4amE5JNtJm7tGNpOVANQeYZueWZ5J+VO2c+F2WWY QTduWm7J7QDFrRn8o0/ckupmuyMCttmBkKzKWBSN5eQXK82vHI/cPXBe/oNmbE7qYLq5 AVxZmNb5L7cSuxz13QLQBNjMt4/XVyLfUSoUUqBk8ZCW1dvT/n0zVmnwEthNWzA7yD11 A6Q68eKZjT3cYTzqKPqAizI0758AtYBIi1jUjJEGJ4TpFFKBUS5UFCLD8/ZLHBjhauC2 NM0UfoQqQLVZca3NmPEH/sNCNyJLtzMbY8RW4q650NwoZM9kkkUf4huLYT4QBChTT1ip aumQ== X-Gm-Message-State: APzg51BNK2DHPETyVH3z4doNLflQer6ce54Y/3923Ch8PMruN4wwaFaC /S0CVPd3iB3jYn0k3GHgHWNpTX1g1Ew5R2zHASM= X-Google-Smtp-Source: ANB0VdZpNFWzO7HnY0xK21Yq9ZTG7zowZX99Hl4FK2lQvnCFycwXcXHPKVY977afL8EnVXX8NfDVHHECrezXJlZ2nUQ= X-Received: by 2002:a37:4ed8:: with SMTP id c207-v6mr21706381qkb.164.1537318418842; Tue, 18 Sep 2018 17:53:38 -0700 (PDT) MIME-Version: 1.0 References: <87efdqcs28.wl-jch@irif.fr> <8736u6cpyu.wl-jch@irif.fr> <87zhweb9lj.wl-jch@irif.fr> In-Reply-To: <87zhweb9lj.wl-jch@irif.fr> From: Dave Taht Date: Tue, 18 Sep 2018 17:53:26 -0700 Message-ID: To: Juliusz Chroboczek Cc: babel-users@lists.alioth.debian.org, Make-Wifi-fast , ecn-sane@lists.bufferbloat.net Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Ecn-sane] [Babel-users] reducing delays in wifi mcast queues X-BeenThere: ecn-sane@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussion of explicit congestion notification's impact on the Internet List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Sep 2018 00:53:39 -0000 On Tue, Sep 18, 2018 at 5:43 PM Juliusz Chroboczek wrote: > > >> Interesting. AFAIK, ECN is only considered by AQM queues, so this imp= lies > >> there's a queue in the way that's dropping Babel packets. > > > There's fq_codel on every queue, which does FQ, and codel assumes > > everything is at least moderately TCP friendly (and/or reasonably > > responsive to ecn marks) > > Jonathan seems to agree with you. > > Were your tests run with more than 60 installed routes or so? yes. I can get an exact amount of ipv4 and ipv6 routes tomorrow, it has been well over 240 in various stages of this net's evolution, but probably below 100 as I write 'cause that main gw is reverted to static routes right now. > >> Or perhaps, if we know which queue that is, > >> we could modify Babel's packet scheduling to be more AQM friendly? > > > How would you describe babel's packet schedulig now? > > The main flaw is that it sends periodic updates as a burst of back-to-bac= k > full-size packets. That could trigger Codel if you had more than 60 > routes or so. > > > So dumping packets in there at a rate no more than 20ms each (short ter= m > > burst of 100ms) - relative to whatever bandwidth can be achieved vs the > > other flows. > > Right. Guilty as charged. Well, packet pacing is now a feature of the tcp stack but not the udp one, but it is good to know something can be done in addition to ecn.... > > -- Juliusz --=20 Dave T=C3=A4ht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619