From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-x236.google.com (mail-oi0-x236.google.com [IPv6:2607:f8b0:4003:c06::236]) (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 0E62E3BA8E for ; Tue, 16 Jan 2018 15:48:32 -0500 (EST) Received: by mail-oi0-x236.google.com with SMTP id m65so11589430oig.5 for ; Tue, 16 Jan 2018 12:48:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ariekanarie-nl.20150623.gappssmtp.com; s=20150623; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=nOrOiJrmC6LBQw7BBsjOMm6uSZnB8f8A+BrACJKclWo=; b=CDHZyDVFTBR5APBncjSARIFIvkd6y8KgDMJYvXw+HFC10dsQpPBBuq4FcJaF3Mliww yBnCGAcTUqjfF+dHI7Zwx0TBCqO+rOqbjBBLA4sI62zIg2YahXJKTS4GMTH1hZW8cSs5 xPcT+QSiP9DPEbCx+WLZlnjFxFFTmXCGVSzpfgaDI/zRXVeN+a3rLGNNpQwur3ank0YZ eNmmQb2KzYW+vDYpay6wjLHJuHsNslBnEVylwdabzP1xo2PesUbdbVQBJlvj3lDz/0lE z/j7/n3hvAb3pGt9YPyFpqctMItbxNt/COS1b96hL2PPZPbbmEFOSd3juDzP+XT9AqaM NXWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=nOrOiJrmC6LBQw7BBsjOMm6uSZnB8f8A+BrACJKclWo=; b=H1OXC0PnyT+HtH3z3X45lPgr8HEqLKY2pSLrY2XfMD8zLh3+605a8kAO6TY6kEB0RH m5ZcqlJciz4EFbZpQ01cYGBZbEExCsFjQ/9y+BC2lIvU0spsc2Cz9GDfVbsmACboKGQx cCBErvu3vayRWDJJHpA7314xVfOioZ8VZ6pyVJSLIub4Z5dVTMpW5PdPzNLpXoIcjy/q qxTUAjVwJnecax7+YqxlN4tQaM2cShxaQz9hJDTF+KhVyWl+yUgXF24TTsIvdCjNWfs6 FL9FR3LEXzRdqF5/8pMC414snED1bAh0QyCaREu1V+bCRrnl/rbFeewjKNI0+jdYdD+2 bssA== X-Gm-Message-State: AKGB3mIPaAmcO7XhIFrthCAzVAM+t73HY7ILhFkCRk0QM1wlbdiDkdUc sjEvrTwaAenhghXyGugAm+0fiRPfyXUw9KK/84Omjg== X-Google-Smtp-Source: ACJfBovfv8RDNTLn9H1x/vYL4SQdtXeExc6c+WknGNkN8cCvwoaJQ+Prr6n+zvsWV/B5RpDqQhfwwP88MuZHbXDUAL0= X-Received: by 10.202.237.194 with SMTP id l185mr16068594oih.227.1516135712302; Tue, 16 Jan 2018 12:48:32 -0800 (PST) MIME-Version: 1.0 Sender: arie@ariekanarie.nl Received: by 10.74.2.77 with HTTP; Tue, 16 Jan 2018 12:48:31 -0800 (PST) X-Originating-IP: [178.85.156.201] In-Reply-To: References: From: Arie Date: Tue, 16 Jan 2018 21:48:31 +0100 X-Google-Sender-Auth: 7Tw09ObZsYHFR5VnGpiIYps51rY Message-ID: To: Dave Taht Cc: bloat Content-Type: multipart/alternative; boundary="001a113ac8e4903f4c0562eada0d" 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 20:48:33 -0000 --001a113ac8e4903f4c0562eada0d Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Not powersave of any component in my control. Powersave of the CMTS? I'd expect high latency for idle pings in that case too. On 16 January 2018 at 20:52, Dave Taht wrote: > Power save? > > On Tue, Jan 16, 2018 at 11:36 AM, Arie wrote: > > Recently I accidentally discovered something quite odd about my home > DOCSIS > > connection (shaped with cake) while running a flent rrul test. > > During the flent rrul test, another machine in my home had started a > Steam > > game update, this opened somewhere between 8-12 connections and > saturated my > > downstream. > > > > The interesting part was the resulting rrul graph, showing perfect > latency > > control during the test, but 100-150ms of bufferbloat at the very start > and > > end of the rrul graph (when rrul is idle, just pinging). > > > > Instead of a Steam download I started an iperf3 client on a remote > machine > > 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 > cake > > (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 > before > > 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 wi= th > > both stock and LEDE firmware, both with fq_codel and cake (on both stoc= k > and > > LEDE firmware). Same results. > > Even without any SQM active, the rrul test still improved the latency o= f > my > > connection when it's also downloading from 8+ connections at the same > time. > > > > 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 sendin= g > > 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 > > > > > > -- > > Dave T=C3=A4ht > CEO, TekLibre, LLC > http://www.teklibre.com > Tel: 1-669-226-2619 > --001a113ac8e4903f4c0562eada0d Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Not powersave of any component in my control. Powersave of= the CMTS? I'd expect high latency for idle pings in that case too.


On = 16 January 2018 at 20:52, Dave Taht <dave.taht@gmail.com> = wrote:
Power save?

On Tue, Jan 16, 2018 at 11:36 AM, Arie <nospam@ariekanarie.nl> wrote:
> Recently I accidentally discovered something quite odd about my home D= OCSIS
> connection (shaped with cake) while running a flent rrul test.
> During the flent rrul test, another machine in my home had started a S= team
> game update, this opened somewhere between 8-12 connections and satura= ted my
> downstream.
>
> The interesting part was the resulting rrul graph, showing perfect lat= ency
> control during the test, but 100-150ms of bufferbloat at the very star= t and
> end of the rrul graph (when rrul is idle, just pinging).
>
> Instead of a Steam download I started an iperf3 client on a remote mac= hine
> that opened 16 connections to a LAN machine. Same behavior as the Stea= m
> download.
>
> At first I thought this was a bug with cake, but no matter how I tuned= cake
> (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 be= fore
> the rrul test kicked off, great latency while rrul was doing its up an= d
> downloads.
>
> So I swapped out my self-compile LEDE router with an Edgerouter ER-X w= ith
> both stock and LEDE firmware, both with fq_codel and cake (on both sto= ck 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 s= ame time.
>
> 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 sendi= ng
> about 300KB/s of empty UDP packets to some unresponsive port on my ISP= s
> local gateway.
>
> I'm puzzled by this result, somehow sending 300KB/s of empty packe= ts
> 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
>



--

Dave T=C3=A4ht
CEO, TekLibre, LLC
ht= tp://www.teklibre.com
Tel: 1-669-226-2619

--001a113ac8e4903f4c0562eada0d--