From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-x22b.google.com (mail-qk0-x22b.google.com [IPv6:2607:f8b0:400d:c09::22b]) (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 149F73BA8E for ; Tue, 16 Jan 2018 14:52:47 -0500 (EST) Received: by mail-qk0-x22b.google.com with SMTP id a5so19567230qkg.10 for ; Tue, 16 Jan 2018 11:52:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=CDXGaTgOtsarWp9O0hObpjnKMBpprViDdH6QtZc5MW0=; b=H+soYy3ZkInXR4Egk2os5qsQq7ZrJ2aCm0l/eFzGQF6u1ut+QBdiBESWzll/4/BRTU zzAcFfeYdQyRJfR93FmHwXC/hF9uF3bBBoTraVRo0+CaCl6meRHAyHLC4jroxqO82syB D2kmGWXaA7ZWT0v0YW4b7zjWC204aYCBApIziq3NsCY4UO/2KRpr48epbW2vxkHPkDBV O6Pzl1OIlu0lMct2XhQ2bD3885oclNNvPfkDdYWkNH2OjqeoB80rSSAGV2/uFcsiB+lq lL0ef0XOuySfed0LfKvZNpv5bsipoVS9w6j37xU9f895NguXCgHSNconyAlP/BYEhmcS Z0xQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=CDXGaTgOtsarWp9O0hObpjnKMBpprViDdH6QtZc5MW0=; b=WreRs/cf+OMV6xJ0uAQVNPdc1lnam90YZhf204qs5ovNitoQy48C/dUdiOGi0QdPB0 ZKTn7/qPhZaxrRYN6Ilxaw3Ks/AUwemU0DQxVKcJCZXfVo0mOsIrdshPnAYGKb1dvNqw YEf6FerhXc1Q5eHJHOjlSd8MwOtSRtxRmDaYKGz/vPZQm9yUsByWIcc7ek8HIHTcTi5u pzcsPexNgdp2P7sae+HZe/b421vSvcOAY3DOhdMRq0gPmnnbyq0IG8XU/gxsfkyIJKWU JORv7XdKS7TGFBLEPlL2lIiAKkS/8gCxGUJ3n4P2t4lievHzKnvt6uSylIma75S2pl33 TMKw== X-Gm-Message-State: AKwxytdgBPjvx9Fz3sTiIVJjoKpSWjfrtImkVRVv+qsShBhUOGk3aaB0 1J3vowOiT8KuxBw3Zvbd5EMblVShugjQJZM+f4A= X-Google-Smtp-Source: ACJfBou6XOr5Mm0TPCOB77OkTLQwHX8HIqwuW1k9YB49R0o75sbIKTqwuxQKpJW/EX3ex0ABrPN37iGglOVbZlIQ6xA= X-Received: by 10.55.102.87 with SMTP id a84mr2916976qkc.75.1516132366625; Tue, 16 Jan 2018 11:52:46 -0800 (PST) MIME-Version: 1.0 Received: by 10.12.189.15 with HTTP; Tue, 16 Jan 2018 11:52:45 -0800 (PST) In-Reply-To: References: From: Dave Taht Date: Tue, 16 Jan 2018 11:52:45 -0800 Message-ID: To: Arie Cc: bloat Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Bloat] Curious bufferbloat on DOCSIS connection with many downloads X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Jan 2018 19:52:47 -0000 Power save? On Tue, Jan 16, 2018 at 11:36 AM, Arie wrote: > Recently I accidentally discovered something quite odd about my home DOCS= IS > connection (shaped with cake) while running a flent rrul test. > During the flent rrul test, another machine in my home had started a Stea= m > game update, this opened somewhere between 8-12 connections and saturated= my > downstream. > > The interesting part was the resulting rrul graph, showing perfect latenc= y > control during the test, but 100-150ms of bufferbloat at the very start a= nd > end of the rrul graph (when rrul is idle, just pinging). > > Instead of a Steam download I started an iperf3 client on a remote machin= e > that opened 16 connections to a LAN machine. Same behavior as the Steam > download. > > At first I thought this was a bug with cake, but no matter how I tuned ca= ke > (limiting my 400/40 connection to 50/20 for example), the behavior was > similar. > I tried fq_codel+htb, and got similar results to cake, high latency befor= e > the rrul test kicked off, great latency while rrul was doing its up and > downloads. > > So I swapped out my self-compile LEDE router with an Edgerouter ER-X with > both stock and LEDE firmware, both with fq_codel and cake (on both stock = and > LEDE firmware). Same results. > Even without any SQM active, the rrul test still improved the latency of = my > connection when it's also downloading from 8+ connections at the same tim= e. > > I managed to take the flent rrul test out of the equation by starting a > hping3 "flood" to the hop next of my cable modem. > >> hping3 -2 -d 0 -s 10080 -k -p 80 -i u100 >> first-hop-or-ISP-gateway-goes-here > > > This also fixed the latency while many downloads were running by sending > about 300KB/s of empty UDP packets to some unresponsive port on my ISPs > local gateway. > > I'm puzzled by this result, somehow sending 300KB/s of empty packets > upstream drastically improves the latency of my connection when it's > receiving many downloads. > > Equipment used: > Cisco EPC3212 cable modem (8x4 EuroDOCSIS 3.0) > Linksys WRT1900ACS router with LEDE > Ubiquiti Edgerouter ER-X with both EdgeOS (stock) and LEDE > > > > > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat > --=20 Dave T=C3=A4ht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619