From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-31-ewr.dyndns.com (mxout-070-ewr.mailhop.org [216.146.33.70]) by lists.bufferbloat.net (Postfix) with ESMTP id 532A22E0136 for ; Wed, 23 Mar 2011 04:27:16 -0700 (PDT) Received: from scan-32-ewr.mailhop.org (scan-32-ewr.local [10.0.141.238]) by mail-31-ewr.dyndns.com (Postfix) with ESMTP id 130996F71BA for ; Wed, 23 Mar 2011 11:27:15 +0000 (UTC) X-Spam-Score: 0.8 () X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 209.85.214.43 Received: from mail-bw0-f43.google.com (mail-bw0-f43.google.com [209.85.214.43]) by mail-31-ewr.dyndns.com (Postfix) with ESMTP id 28E726F9C2F; Wed, 23 Mar 2011 11:27:10 +0000 (UTC) Received: by bwz14 with SMTP id 14so8593287bwz.16 for ; Wed, 23 Mar 2011 04:27:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:references:in-reply-to:mime-version :content-transfer-encoding:content-type:message-id:cc:x-mailer:from :subject:date:to; bh=hhDB7yimKh3sHIP1/cFVHpEHETymOfpMNZKP+b3ExjE=; b=C/Hzb3eSgmWnMLw0ZHsPQbgqjOELFl0RWk/CdmT3h1y7aGySLkNor0UPCM/bjZSqb4 Qi0E0i4TI/rcOwd4IXKTGurh7qg5gGq8k5NtxSXJJVdnHGz6V3ygXMuxhpX1oq5Q2j4v m7ZAuUOCeEjhNz5cBbXJbrPNwAxrYPGjqXDOc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=references:in-reply-to:mime-version:content-transfer-encoding :content-type:message-id:cc:x-mailer:from:subject:date:to; b=mAJcqtlbqctjQi1z/Tqwi8Pzi+E3DfOiZUyM9zGn3bx/K07gP0pmB/LRjTTzaEj27W UrB/igTQwAqQGUiVrCO86byDVstNDgN5KW38NyIVuKlx6a2Ux5PP7OJIVJo3R4xsGaJY ssanQQvPIPVnOqlaKu0GxLuimMqA7UT8qvbK0= Received: by 10.204.169.130 with SMTP id z2mr6063327bky.137.1300879629342; Wed, 23 Mar 2011 04:27:09 -0700 (PDT) Received: from [87.95.197.41] (87-95-197-41.bb.dnainternet.fi [87.95.197.41]) by mx.google.com with ESMTPS id l1sm2060605bkl.1.2011.03.23.04.27.05 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 23 Mar 2011 04:27:08 -0700 (PDT) References: <0D59AD34-AA64-4376-BB8E-58C5D378F488@gmail.com> <4D829B58.1070601@swin.edu.au> <20110323103357.GG30600@guug.org> In-Reply-To: <20110323103357.GG30600@guug.org> Mime-Version: 1.0 (iPhone Mail 8C148) Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Message-Id: X-Mailer: iPhone Mail (8C148) From: Jonathan Morton Date: Wed, 23 Mar 2011 13:26:59 +0200 To: Otto Solares Cabrera Cc: bloat , bloat-devel Subject: Re: [Bloat] Progress with latency-under-load tool X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Mar 2011 11:27:16 -0000 Unfortunately that patch will not work - it completely breaks part of the on= -wire protocol. It is much better to simply convert the final results for an= auxiliary display.=20 At the moment I am working to prove that high smoothness and responsiveness c= an actually be measured, which requires first setting up a network which can= genuinely achieve it. I was surprised to find that pure Ethernet was not by= default sufficient, though it is easily explainable.=20 I should also point out that I have very strong reasons for providing the me= asurements in non-traditional units by default. I'm measuring characteristic= s as they matter to applications and users, who measure things in bytes and f= rames per second, not bits and milliseconds. It is also much easier to get n= ontechnical people (who tend to be in charge of budgets) to respond to bigge= r-is-better numbers.=20 The key to knowledge is not to rely on others to teach you it.=20 On 23 Mar 2011, at 12:33, Otto Solares Cabrera wrote: > On Sun, Mar 20, 2011 at 12:45:10PM +0200, Jonathan Morton wrote: >> Attached is the initial version of the loadlatency tool. I'm getting som= e rather interesting results from it already, although it does take a very l= ong time to run. >>=20 >> It works under Linux, Cygwin and MacOS X on both little- and big-endian m= achines (and between machines of different byte-sexes), and therefore it sho= uld also work under FreeBSD and other UNIXes. I haven't yet tried compiling= it for iOS or Android. >>=20 >> It produces useful results even when one of the machines is rather old an= d slow, despite using a proper PRNG for traffic generation. My ancient Pent= ium-MMX proved capable of generating at least 4.4 MB/s of traffic steadily, a= nd probably produces spikes of even greater bandwidth. Anything of Y2K vint= age or newer should be able to saturate it's network with this. >>=20 >> There are four measures produced: Upload Capacity, Download Capacity, Li= nk Responsiveness and Flow Smoothness. All of these are reported in "bigger= is better" units to help deal with Layers 8 and 9. >=20 > Hello Jonathan, >=20 > Excellent tool! hopefully with more testing we can validate it's > results and improve it as testing all those scenarios seems the > correct path to understand bufferbloat and latency in our networks. >=20 > Sadly it's very difficult for a netadmin like me to follow your "units" > as the world have been standarized on bits per second in base10 or > decimal as opposed to the bytes per second in base2 or binary as > reported by this tool, "smoothness" too is a very radical unit to > measure latency which could be in milliseconds as the tool name implies. >=20 > Please don't take it as an offense but I cooked this small patch to > address this problems in the case you want to change it or for others > if they feel the need for more "normal" measuring units which in turn > can lead to more people testing their networks with this tool. >=20 > It's a diff against nbd's git repository, it seems to work for me but > honestly I have yet to figure out all the data it reports, hopefully > I didn't b0rk it too much :) > - > Otto >