From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org (plane.gmane.org [80.91.229.3]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id 4891B21F19D for ; Tue, 19 May 2015 14:23:24 -0700 (PDT) Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1Yuoyt-0001nT-Dz for bloat@lists.bufferbloat.net; Tue, 19 May 2015 23:23:19 +0200 Received: from host-89-243-100-239.as13285.net ([89.243.100.239]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 19 May 2015 23:23:19 +0200 Received: from alan.christopher.jenkins by host-89-243-100-239.as13285.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 19 May 2015 23:23:19 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: bloat@lists.bufferbloat.net From: Alan Jenkins Date: Tue, 19 May 2015 22:23:05 +0100 Message-ID: <555BA9B9.1070108@gmail.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> <1E4513D8-FAEB-4D51-969E-093FA4929D89@pnsol.com> <87383l3ktd.fsf@toke.dk> <87tww122yw.fsf@toke.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: host-89-243-100-239.as13285.net User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 In-Reply-To: <87tww122yw.fsf@toke.dk> 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: Tue, 19 May 2015 21:24:02 -0000 On 27/04/15 13:03, Toke Høiland-Jørgensen wrote: > 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 I may be too slow and obvious to be interesting or just plain wrong, but... A network developer at Google seems to think end-to-end is not yet played out. And that they *do* have an incentive to improve behavior. https://lists.bufferbloat.net/pipermail/bloat/2015-April/002764.html https://lists.bufferbloat.net/pipermail/bloat/2015-April/002776.html Pacing in sch_fq should improve video-on-demand. HTTP/2 also provides some improvement for web traffic. *And* the multiplexing should remove incentives for websites to stop forcing multiple connections ("sharding"). The incentive then reverses because connect() (still) requires an RTT. The two big applications blamed by the article, mitigated out of self-interest? :-). I can believe dQ / other math might require more than that. That hiding problems with more bandwidth doesn't scale. ISPs suffering is more difficult to swallow from a customer point of view. But still... 'Worse is better' [just-in-time fixes] has been a very powerful strategy. What does the first step look like, and what is the cost for customers? Strawman: How hard is a global _lower_-priority class? Couldn't video-on-demand utilize it to fill an over-size buffer and then smooth over these 30 seconds of transient congestion? Alan