From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-x22f.google.com (mail-qt0-x22f.google.com [IPv6:2607:f8b0:400d:c0d::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id D11233B2A4 for ; Tue, 12 Jun 2018 07:40:56 -0400 (EDT) Received: by mail-qt0-x22f.google.com with SMTP id h5-v6so23266112qtm.13 for ; Tue, 12 Jun 2018 04:40:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=t3WiDqXpojfOx0qXZgwZhmsqLSZgOMYlKfUPHAdFyrQ=; b=K9pI/H+3onjFLnt0tvb+poogLc9qzu/xkFa/5Sy1FldiaXJLGdmfGXuhUp5A8V1jJM DLdy4eY+EKsqZyEYhojIb2t8wezJj8Ejs3YUlLlgtgalrlS7uc5hoLJLAlGH7ootTvhv wpUlgLS3IG1DLMukdtoJRDOi5l8jmE4DPwX3BWWi/nmeVK1aNwmDy1XV9fCyYfIfE6YC JX481qY2E4QFFhIFJkxRBW68vum+h1zsrqlDYew9bzpTQ6wmRdX6HtArxFKPesz+hbM7 pu8kDz9R+p4HXp1hftEjY1nSSKnRV3yv0gz9HNhZeotfMv998Lp0rVddwWizLiZa6Fda zMWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=t3WiDqXpojfOx0qXZgwZhmsqLSZgOMYlKfUPHAdFyrQ=; b=YecTZxE9vpcjegSenXhIB5x0srG6c2G8aWGyX2FLnSF77BnB/u9fZEJUxdD9nLYXbi WDSFczGEuZx73E9KBz4IMZvFFHl9P85sGWC8swsfEjMhyvYkRYFsPdjgoaMbMjNGP0lj 889DJYFpeJFvJtnZHFWSHdCOEKsk6gTXui1tDJuADkYU24r4Y2Lp0Ca6B8eBeK1jry7C dPlgU+5jyKU/dxMvnZSdDjlw1i7RA+O/xcyY+A2xGjl+GGqeSBb91meqWpVQZ/3T/MnB U8xBh8BHk5PYqAUmTwHsB8zzl+3tkHQLYCJt/rJ2pl0n1oQHKGo+FSaHhBUFaCkOcoNU qRTQ== X-Gm-Message-State: APt69E0k/ZWJtmWK9f8gjyN0ES9Zjx/ANCeFF1T40PPzRyLIGv+HQyjl t3pjIKs/t22hgUEN8Azooh9YjwYUy+Aa/nC3gx4= X-Google-Smtp-Source: ADUXVKKRaKvWcRQnzae7uPScoWt6gthRZbLlbf2ZdeRo1oIeYO9ASJpeedL/vtgL0rYYw964OTqyVhzlMkHbfdPsK/A= X-Received: by 2002:aed:24fb:: with SMTP id u56-v6mr3041026qtc.203.1528803656389; Tue, 12 Jun 2018 04:40:56 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:aed:24f0:0:0:0:0:0 with HTTP; Tue, 12 Jun 2018 04:40:55 -0700 (PDT) In-Reply-To: <1b46d724-6568-c4ee-9860-86ae504434a3@kit.edu> References: <87in6ohm30.fsf@toke.dk> <7adae673-d701-6fe0-1d47-524320d38583@gmx.net> <1b46d724-6568-c4ee-9860-86ae504434a3@kit.edu> From: Dave Taht Date: Tue, 12 Jun 2018 04:40:55 -0700 Message-ID: To: "Bless, Roland (TM)" Cc: Matthias Tafelmeier , bloat , =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Bloat] geoff huston's take on BBR X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Jun 2018 11:40:56 -0000 On Tue, Jun 12, 2018 at 12:36 AM, Bless, Roland (TM) wrote: > Hi, > > Am 12.06.2018 um 07:09 schrieb Matthias Tafelmeier: >> On 06/12/2018 02:42 AM, Toke H=C3=B8iland-J=C3=B8rgensen wrote: >>>> https://ripe76.ripe.net/presentations/10-2018-05-15-bbr.pdf >>> "More research needed". Naturally ;) >>> >>> (But yeah, good points overall) >> >> Interesting. Potentially, all affectuated. After having applied the BBR >> 2.0, we might are back to Cubic? :D > > I don't understand what you're saying. I think Geoff tested BBR v1.0. > Explanations for the experienced behavior can be found in our paper > http://doc.tm.kit.edu/2017-kit-icnp-bbr-authors-copy.pdf, esp. section > 3. Geoff's findings in the wild nicely confirm our results that were > performed in more controlled lab settings. Important is though, that > you always test with multiple concurrent BBR flows... we always do that, 'round here, with flent. Glad more folk are doing it. :) >> Moreover, if it tends to be unstable on larger scale - what is Google >> doing then? Thought they've got a more or less homogeneous BBR driven >> TCP flow ecosystem - at least internally!? Was all propaganda? When >> speculating, might working for them since of centrally handled flow >> steering approaches - "imposing inter-flow fairness". > > There are certain situations where BBR might work well: > 1) you only have a single flow at the bottleneck, might be the case in > their B4 scenario > 2) The senders a application limited (e.g., YouTube) I think the application limited scenario is the primary one. once typical links are fully capable of video streaming 4k video a lot of the demand for better congestion control will drop. > 3) The bottleneck buffer is much larger than a BDP > (then BDP will limit the queue size between 1 and 1.5 BDP) Sadly we still see 2sec queues on cmtses, in particular. > However, BBR has no explicit fairness mechanism, so sometimes > one will see quite unfair shares for longer periods, > even if there are only BBR flows present at then bottleneck. except with fq at the bottleneck. > > Regards > Roland > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat --=20 Dave T=C3=A4ht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619