From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp141.iad.emailsrvr.com (smtp141.iad.emailsrvr.com [207.97.245.141]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id 95680202295 for ; Wed, 22 Aug 2012 11:23:44 -0700 (PDT) Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp44.relay.iad1a.emailsrvr.com (SMTP Server) with ESMTP id 02EB3128322; Wed, 22 Aug 2012 14:23:43 -0400 (EDT) X-Virus-Scanned: OK Received: from legacy1.wa-web.iad1a (legacy1.wa-web.iad1a.rsapps.net [192.168.2.217]) by smtp44.relay.iad1a.emailsrvr.com (SMTP Server) with ESMTP id CC0FA128779; Wed, 22 Aug 2012 14:23:42 -0400 (EDT) Received: from reed.com (localhost [127.0.0.1]) by legacy1.wa-web.iad1a (Postfix) with ESMTP id A8FD247880B2; Wed, 22 Aug 2012 14:23:42 -0400 (EDT) Received: by apps.rackspace.com (Authenticated sender: dpreed@reed.com, from: dpreed@reed.com) with HTTP; Wed, 22 Aug 2012 14:23:42 -0400 (EDT) Date: Wed, 22 Aug 2012 14:23:42 -0400 (EDT) From: dpreed@reed.com To: "Sebastian Moeller" MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_20120822142342000000_92570" Importance: Normal X-Priority: 3 (Normal) X-Type: html In-Reply-To: References: <36D61FDC-9AA9-46CC-ACBB-2D28B250C660@gmx.de> <2998C331-777B-41B3-A6BC-8285461EF729@gmx.de> <1345516397.664231592@apps.rackspace.com> Message-ID: <1345659822.690830074@apps.rackspace.com> X-Mailer: webmail7.0 Cc: "cerowrt-devel@lists.bufferbloat.net" Subject: Re: [Cerowrt-devel] cerowrt 3.3.8-17 is released 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: Wed, 22 Aug 2012 18:23:44 -0000 ------=_20120822142342000000_92570 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =0AAhhh, thanks, Sebastian. Now I understand what you are doing is a stre= ss test.=0A =0A =0A =0A =0A =0A =0A =0A-----Original Message-----=0AFrom: "= Sebastian Moeller" =0ASent: Tuesday, August 21, 2012 1:28a= m=0ATo: "Marchon" =0ACc: "dpreed@reed.com" , "cerowrt-devel@lists.bufferbloat.net" =0ASubject: Re: [Cerowrt-devel] cerowrt 3.3.8-17 is released=0A=0A=0A= =0AHi there,=0A=0Aagain the UDP flood test was not about the cable modem bu= t just about resilience under (extreme) load. So just plain bread and butte= r functionality of a router, nothing fancy :) As is it causes a mix of very= slow processing due to allocation errors and occasional OOM situations and= full reboots. IMHO surviving the stress without these unfortunate outcomes= would be preferable=E2=80=A6=0A=0A=0Abest=0A Sebastian=0A=0AOn Aug 20, 201= 2, at 7:44 PM, Marchon wrote:=0A=0A> It The Fq_codel settings prevent exces= s buffering on the push of data out over the cable modem itself / it will p= revent unnecessary premature reduction of the tcp sliding window size furt= her preventing a cascading backlog that ends up further reducing the slidin= g window and slowing down the overall outbound transfer rate. =0A> =0A> A b= uffering problem in the cable modem only happens if you feed it data to qui= ckly. =0A> =0A> =0A> =0A> =0A> =0A> =0A> Sent from my iPhone=0A> =0A> On Au= g 20, 2012, at 10:33 PM, dpreed@reed.com wrote:=0A> =0A>> I'm confused. Fq= _codel does not (to my knowledge) fix bufferbloat *in your cable modem* or= *in the CMTS head-end*.=0A>> =0A>> How could it? In order for that to b= e fixed, you need to manage the buffer in the cable modem itself.=0A>> =0A= >> -----Original Message-----=0A>> From: "Sebastian Moeller" =0A>> Sent: Monday, August 20, 2012 2:24pm=0A>> To: "Dave Taht" =0A>> Cc: cerowrt-devel@lists.bufferbloat.net=0A>> Subject: Re= : [Cerowrt-devel] cerowrt 3.3.8-17 is released=0A>> =0A>> Hi Dave,=0A>> =0A= >> so I went to play around with this a bit more. I turned to UDP flooding = my cable modem through the router and this surely allows me to create enoug= h load on the wndr3700v2 to cause the allocation errors and as a "bonus" al= so to drive the router to reboot (driven by the watchdog timer?). Here is t= he script I used over 5G wireless (from http://blog.ioshints.info/2008/03/u= dp-flood-in-perl.html)=0A>> =0A>> #!/usr/bin/perl=0A>> ##############=0A>> = =0A>> # udp flood.=0A>> ##############=0A>> =0A>> use Socket;=0A>> use stri= ct;=0A>> =0A>> if ($#ARGV !=3D 3) {=0A>> print "flood.pl =