From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.19]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass DE-1" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id BB0F321F521 for ; Sat, 30 Aug 2014 11:38:18 -0700 (PDT) Received: from android-2407274cafd9c69c.fritz.box ([87.240.238.110]) by mail.gmx.com (mrgmx001) with ESMTPSA (Nemesis) id 0LymHf-1YSqWm06SN-016AsD; Sat, 30 Aug 2014 20:38:15 +0200 User-Agent: K-9 Mail for Android In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable From: Sebastian Moeller Date: Sat, 30 Aug 2014 20:21:04 +0200 To: Aaron Wood ,Dave Taht Message-ID: <72b3bdbb-e78b-4699-bef0-c4c93cae4b76@email.android.com> X-Provags-ID: V03:K0:rdUOduVFrasBuMwK8IxBRmWHOqx4mizG0AD6WNHHyrzXNFvWmt1 ALEbGAfAunAE1uXmCzN0LcDWf5fyYD0s7ahUI0DUA1b+V6lhPk9zgnFitAb/QcmUVxtRj13 GubtRPLhv4zzLNYUV9dUJ/esUR3Zvr0j55r9MfWjd+N+dMceK6egqHwCD9ZNu9+atWNNaZ/ o7vHwlcBr3/qa03AziziQ== X-UI-Out-Filterresults: notjunk:1; Cc: cerowrt-devel , bloat Subject: Re: [Cerowrt-devel] [Bloat] Comcast upped service levels -> WNDR3800 can't cope... X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 30 Aug 2014 18:38:19 -0000 Hi Aaron On August 30, 2014 7:19:17 PM CEST, Aaron Wood wrote= : >On Fri, Aug 29, 2014 at 11:06 AM, Dave Taht >wrote: > >> On Fri, Aug 29, 2014 at 9:57 AM, Aaron Wood >wrote: >> > Comcast has upped the download rates in my area, from 50Mbps to >100Mbps=2E >> > This morning I tried to find the limit of the WNDR3800=2E And I >found it=2E >> > 50Mbps is still well within capabilities, 100Mbps isn't=2E >> > >> > And as I've seen Dave say previously, it's right around 80Mbps >total >> > (download + upload)=2E >> > >> > >> >http://burntchrome=2Eblogspot=2Ecom/2014/08/new-comcast-speeds-new-cerowr= t-sqm=2Ehtml >> >> Thank you very much, as always, for doing public benchmarking with a >good >> setup! >> > >No problem, I find this sort of investigation a lot of fun=2E Even if it >is >somewhat maddening at times=2E > > >> Yes we hit kind of an unexpected wall on everything shipped with a >> processor >> originally designed in 1989, and the prevalance of hardware offloads >to >> bridge >> the gap and lower costs between 100mbit and a gige is a real PITA=2E >> > >Do you think this is a limitation of MIPS as a whole, or just the >particular MIPS cores in use on these platforms? > I think that the last MIPS-based SGI systems could saturate at leas= t Gbit Ethernet, so it does not seem to be generic to MIPS as an architectu= re=2E=2E=2E=20 >OTOH, I have noticed that MIPS is losing ground to ARM as bandwidths go >up=2E I have a gut-feeling that this change is driven by economics and not t= echnical superiority=2E=2E=2E > The router SoCs that I'm seeing from the usual suspects have been >switching from MIPS to ARM over the last year or two=2E The WNDR is in >the >top-tier for SOHO SoCs, but at a product family is getting long in the >tooth=2E > > >> > I tried disabling downstream shaping to see what the result was, >and it >> > wasn't pretty=2E >> >> Well, I'll argue that only seeing an increase of 20ms or so with the >> upstream >> only, fq_codeled, (vs 120ms not) is not bad and within tolerances of >most >> applications, even voip=2E Secondly the characteristics of normal >> traffic, as opposed >> to the benchmark, make it pretty hard to hit that 100mbit download >limit, >> so a mere outbound rate limiter will suffice=2E >> > >Well, yes=2E=2E=2E I have considered just turning it off entirely, as th= e >the >extra latency isn't awful=2E And frankly, the laptops (individually) >never >see that sort of bandwidth, but the AppleTV might when downloading >video (I >need to go see what the downloads are capped at by Apple)=2E > > >The cpu caches are 32k/32k, the memory interface 16 bit=2E The rate >limiter >> (the thing eating all the cycles, not the fq_codel algorithm!) is >> single threaded and has global locks, >> and is at least partially interrupt bound at 100Mbits/sec=2E >> > >This is interesting, and lines up with Sebastian's idea about perhaps >using >ethtool to lock the upstream interface to 100Mbps=2E Except that moves >the >bottleneck to the next upstream device=2E=2E=2E (modem), with it's buffer >mgmt, >so maybe that's not a great idea, either=2E Upstream is certainly where >the >biggest issues are=2E Well, my proposal (actually its an idea Dave floated some time ago)= in full is to set the WAN interface to 100mbps and only run sqm on the egr= ess=2E=2E=2E This should keep both bottlenecks under control=2E I assume th= at you get 100 plus some slack from your ISP, so that 100mbps Ethernet is s= till a bit faster Best Regards Sebastian > >> > Or should I start looking for something like this: >> > >> > >http://www=2Egateworks=2Ecom/product/item/ventana-gw5310-network-processo= r >> > >> > (although that's an expensive board, given the very low production >> volume, >> > for the same cost I could probably build a small passively-cooled >> > mini/micro-atx setup running x86 and dual NICs)=2E >> >> There is that option as well=2E I would certainly like to find a low >end x86 >> box >> that could rate limit + fq_codel at up to 300Mbits/sec=2E Toke's x86 >boxes >> have proven out to do 100Mbit/10Mbit correctly, but I don't remember >their >> specs, nor has he tried to push them past that, yet=2E >> > >If I do get my hands on a Ventana board (I may still for work >purposes), >I'll certain set it up and see what it does in this scenario, too=2E > >-Aaron > > >------------------------------------------------------------------------ > >_______________________________________________ >Cerowrt-devel mailing list >Cerowrt-devel@lists=2Ebufferbloat=2Enet >https://lists=2Ebufferbloat=2Enet/listinfo/cerowrt-devel --=20 Sent from my Android device with K-9 Mail=2E Please excuse my brevity=2E