From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-la0-f97.google.com (mail-la0-f97.google.com [209.85.215.97]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id A282C21F151 for ; Mon, 27 Apr 2015 03:37:51 -0700 (PDT) Received: by labgd6 with SMTP id gd6so2175347lab.2 for ; Mon, 27 Apr 2015 03:37:49 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:content-type:mime-version:subject:from :in-reply-to:date:cc:content-transfer-encoding:message-id:references :to; bh=d2a5RWoO+WP8WDLq2W3kFjJxvjgOoBuPEvsYKUTqkL4=; b=OV6MW/AEF7cicb+xw/ANBWEquEvGB3W7iChnw6jzeFAm7tfbsblI7Ct4iGgr7rK4GG lI1Agb4CLeQlwm2Zl1mWaaLWpWLHVItUVMvzDYDpYbl6DZRFbxVjXb53gDEy8WQxbrp8 IsyJH6YzBD6IXBp2YLq4Qo07utq53bR9sp3KDu622LrBAjsXalDaa5GkUpSHfHmDV3CB Ce/qKCow8HLc4hDniHs03v/ebak38nrVTml8Ae7DOIHRWUXojbwoAcN9gZ0ivG7Ma5Sx nQr5im1Hw8g34UokmCt1rN/H7JnfFq1IQpTNrf9zAl1nEdKpdJ4lYOR56qrBesRfxz3o ZAJw== X-Gm-Message-State: ALoCoQmuUvc68/tWdBSNLdt7A7TMDiRqdjWGqLZRF6esK6gNIHBmSto+vOWoQc2acLIc6J3IVe4G8Y/MwsPorpbw3W3WEwwKLg== X-Received: by 10.195.18.103 with SMTP id gl7mr20684920wjd.34.1430131069257; Mon, 27 Apr 2015 03:37:49 -0700 (PDT) Received: from mail.la.pnsol.com (eu1sys200aog114.obsmtp.com. [207.126.144.137]) by mx.google.com with SMTPS id s9sm346929wia.2.2015.04.27.03.37.48 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Mon, 27 Apr 2015 03:37:49 -0700 (PDT) X-Relaying-Domain: pnsol.com Received: from mail.la.pnsol.com ([89.145.213.110]) (using TLSv1) by eu1sys200aob114.postini.com ([207.126.147.11]) with SMTP ID DSNKVT4RetHf+Fok0g6aqVY5GcLqOYQhsR9J@postini.com; Mon, 27 Apr 2015 10:37:48 UTC Received: from ba6-office.pnsol.com ([172.20.5.199]) by mail.la.pnsol.com with esmtp (Exim 4.76) (envelope-from ) id 1YmgQ4-0001RS-A9; Mon, 27 Apr 2015 11:37:44 +0100 Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) From: Neil Davies In-Reply-To: <87fv7l3lqo.fsf@toke.dk> Date: Mon, 27 Apr 2015 11:38:38 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: <1E4513D8-FAEB-4D51-969E-093FA4929D89@pnsol.com> References: <87r3r53ncb.fsf@toke.dk> <04A0C729-6E87-49C6-84F7-3428F236CA15@unimore.it> <3DC1A2EA-6DDD-4FF9-AD12-BB509EFB96B8@unimore.it> <30560030-8A86-481D-A310-B3B72C26C368@pnsol.com> <87fv7l3lqo.fsf@toke.dk> To: =?windows-1252?Q?Toke_H=F8iland-J=F8rgensen?= X-Mailer: Apple Mail (2.1878.6) Cc: bloat Subject: Re: [Bloat] Detecting bufferbloat from outside a node 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: Mon, 27 Apr 2015 10:38:20 -0000 Toke Absolutely - the individual nodes can make (locally informed) decisions = as to how to =93behave=94. The interesting thing is making all those local decisions add up to a = (set of) end-to-end outcomes, and the answer is not to make the same decision(s) everywhere - unfortunately = that doesn=92t stack up. We have (some level) of control over our =93universe of discourse=94 - = my joke with my mates at CERN is that they only have one universe to investigate, we can create three in one = day and still be home in time for tea! Neil On 27 Apr 2015, at 11:32, Toke H=F8iland-J=F8rgensen = wrote: > Neil Davies writes: >=20 >> You are asking about the epistemology! Good start. The only things = you >> can =93know=94 outside the node are the things you can observe. You = can >> infer, from the characteristics of the observations, conformance to >> some avowed model of behaviour. >=20 > If we're going all philosophy of science on this, I'll add that the = nice > thing about networking is that the computers attached to it can give = us > some very specific measurements and we can (with care) provoke quite > specific behaviour to reason about the performance. Try asking a > biologist about the interactions between the life cycle of parasitic > species, their hosts and the ecosystem they live in! :) >=20 > -Toke