From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail2.tohojo.dk (mail2.tohojo.dk [77.235.48.147]) (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 A085D21F1A8 for ; Mon, 27 Apr 2015 05:03:12 -0700 (PDT) X-Virus-Scanned: amavisd-new at mail2.tohojo.dk Received: by alrua-kau.kau.toke.dk (Postfix, from userid 1000) id D123CC40134; Mon, 27 Apr 2015 14:03:03 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toke.dk; s=201310; t=1430136184; bh=lUr8JfySty/Gw1+8G7hdUZEWIx4ngmS0a7y8g0tPxs4=; h=From:To:Cc:Subject:References:Date:In-Reply-To; b=KSy831w2EAXYDDeQhYkLRQ5tE1uQdJYN+mVdpxz33pa2wFpdYyoegq6CF71/4pIWz h/pcn3eOG+vDxY40bRL29ClUtLd81uoeLCOdSvIMk5jAPkYxCoJo/KHpL+8jrhiP4p Epw11z1X0PT8EgUF8Gc0K2T8HA8ffQSp08OuFTHo= From: =?utf-8?Q?Toke_H=C3=B8iland-J=C3=B8rgensen?= To: Neil Davies 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> <1E4513D8-FAEB-4D51-969E-093FA4929D89@pnsol.com> <87383l3ktd.fsf@toke.dk> Date: Mon, 27 Apr 2015 14:03:03 +0200 In-Reply-To: (Neil Davies's message of "Mon, 27 Apr 2015 12:03:35 +0100") X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <87tww122yw.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain 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 12:03:41 -0000 Neil Davies writes: > I don't think that the E2E principle can manage the emerging > performance hazards that are arising. Well, probably not entirely (smart queueing certainly has a place). My worry is, however, that going too far in the other direction will turn into a Gordian knot of constraints, where anything that doesn't fit into the preconceived traffic classes is impossible to do something useful with. Or, to put it another way, I'd like the network to have exactly as much intelligence as is needed, but no more. And I'm not sure I trust my ISP to make that tradeoff... :( > We've seen this recently in practice: take a look at > http://www.martingeddes.com/how-far-can-the-internet-scale/ - it is > based on a real problem we'd encountered. Well that, and the post linked to from it (http://www.martingeddes.com/think-tank/the-future-of-the-internet-the-end-to-end-argument/), is certainly quite the broadside against end-to-end principle. Colour me intrigued. > In someways this is just control theory 101 rearing its head... in > another it is a large technical challenge for internet provision. It's been bugging me for a while that most control theory analysis (of AQMs in particular) seems to completely ignore transient behaviour and jump straight to the steady state. -Toke