From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 644893CB37 for ; Tue, 14 Mar 2023 12:38:51 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.de; s=s31663417; t=1678811928; i=moeller0@gmx.de; bh=XfF6gTtFs64Pa4I2sr48HaIuPNB8r/ZyYSM3m9yFBGc=; h=X-UI-Sender-Class:Subject:From:In-Reply-To:Date:Cc:References:To; b=h2LPXpDU8oezZcVC2CCaU2YpCKy7ntfCWdBmMuY/O8Ojhos1irkAizyldlf+Q6BzL 7pt620taZYJw5J1hFRS4DKJ6CYig/qURA38TQOOdgnoC5w70N0y2Lvo/ltOcP9vd8V TWSjPxRWoyeHCsPBiF755TQGzknOczdUd8/AD0ymqP7nCV2lJUOsb9bsI6n49r5bAg wxTwxXpj+si30fSIbRVHNec5SbpiIsg4evXZFR6062mpvH1OBx8n3Y8+mkz+EK2nBu kpWdjNBp/cTyBlAn2g1JvUm/5XUqUWFH90+HEOj5ivzqIgxSpzeKMk2VZOrczDe+0N R74gFpppv6FgQ== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from smtpclient.apple ([134.76.241.253]) by mail.gmx.net (mrgmx004 [212.227.17.190]) with ESMTPSA (Nemesis) id 1Mplc7-1qJ9Wv1wBp-00qAV0; Tue, 14 Mar 2023 17:38:48 +0100 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.120.41.1.2\)) From: Sebastian Moeller In-Reply-To: Date: Tue, 14 Mar 2023 17:38:47 +0100 Cc: Ruediger.Geib@telekom.de, Cake List , tsvwg IETF list Content-Transfer-Encoding: quoted-printable Message-Id: <6FEAB4C1-0849-4166-9725-46CC91D79A7B@gmx.de> References: <167348364734.15098.9183646444272144529@ietfa.amsl.com> <659CE6DE-2B9D-4210-BAF8-BCC99E2ED875@cablelabs.com> <7434C6A7-4CED-4D39-A852-2714AB9DA1DC@cablelabs.com> To: =?utf-8?Q?Dave_T=C3=A4ht?= X-Mailer: Apple Mail (2.3696.120.41.1.2) X-Provags-ID: V03:K1:e1okrW49Y1f8nbQsC27pAZs7yiBzOvfQyOfrJWhVfttvJWm4UdR asFYKj+KLPdX3S3HpeyTNPxA74GVEvhJPt3mYTA0eQaNWdRMzcoxc/v0ybWsfomD33Z4D1q Nim7+iQTeZmjXvZrSbTNPqNXGBl2bjUwxMm1hTeX/2mFUKZWvkhyMjQYw/VggqBwBxGyXBl o1Ro9Ayfgs/1w5NrT5fxQ== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:/GwwGi0HDFc=;SS4fdB1+Dc71b9l60NJdPQtTEkD 6EjkWKNPDXSBLECxa9GTctXv2s8tP/mnn+d/UqZ4E0Qhfv6Je+Ju7HwMpOfZRPvHH/hVONfz2 J5GTuNiNG6aLD3Hzw2VzEygTxKJpBgUThUFbj7iLS5X773pev85nPC8W1uXLHYcaJXXuLpPYK sVyG19oSR2oLi2l8AR5fOZpBdPPQ/l+oqN9yidk27R6H5yZoA0NM+A5LgVa+6K5261NOTZks7 /gHAgy8zNO+8KZvQQKhfijaxBOPvFKbHMo8Th7CjgShu23SQYXwnQB3l0EBkTYNQ0TI64O645 5D50iqz3m+AgNM8TcnTHVgSjO8SH7JyHpaCoIYlaBp1UzgPiJfUDu6d5T9F+LAJq1Pe9J+Bby 9G+Ckkg8WTJI0sq5CoNTJ8jiUGXbBsxVBg6JOHZ6/lPzMd6uOaKPGf8CE0Nawx2Lg+bykWLwJ H578DE9b+XSEQYnNdbJ+I/YGi73WA8VQZzgJedfDPSnB1LkrW9Eh27hwH+fEtZlm/R/SjVYYM 5UqCeyEpfJchhskFutbg9tjR/+2/uyDqcCWi7gSES5mqfghoxxq3Yz7wtdg3xgYUtqS5FtKrZ LfBz9JGLXya1J64RK4pU6z8RfOu4MvmOyxRyLrkusOIe1prxB82uqf9RrOoxaF82jWImrMgu5 l0O63jlLp2vt7hPNZ5coHh1u4mKmk0hgGfsb6Dqs5qiRjU63b/kliIO7uOjA3wueHoJ7j1dhi jWZ97erCKGKHzBrwjLjxw6gAj+kWT8EPgbYumF6YGiBEhO5JdTd6amFOyuLQZkOlqtf9wntju wXBJcMAXp7sHTyuH+Hnexu4XcsGtzhEUDI4l4uIxRMf0capymAl5PO53Vf0T8TkVWg0mzhWKD b48o4L58UaCYy/QbSAZxG5Xdzdf8T2TxozzkXEukgXzi2pM5yobpRbVCAPpQZ6ZZfT7u1BrCz 7btJI1o6C+6rM2V9VCl0ytGSKgE= Subject: Re: [Cake] [tsvwg] draft-ietf-tsvwg-nqb-15.txt vs the cake AQM X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Mar 2023 16:38:51 -0000 Hi Dave, > On Mar 14, 2023, at 15:01, Dave Taht wrote: >=20 > I have been sitting on the cake related patches for this for years > now, and it is my hope to get support for NQB into the next linux > release, regardless of whether it gets through last call at this time, > unless the selected codepoint number changes. (?) >=20 > Cake (please see the man page here: > https://man7.org/linux/man-pages/man8/tc-cake.8.html ) supports > multiple diffserv models. >=20 > besteffort is exactly that, besteffort, and will not gain NQB support. >=20 > The diffserv3 interpretation is the default, and given that flow > queuing handles most of the NQB-like problems naturally, and Voice > (CS7, CS6, EF, VA, TOS4) is all that is handled there today, I am > thinking of *not* elevating NQB into that class is the right thing. >=20 > NQB fits nicely into the diffserv4 model in the video class, so I will > put it there. since covid we tend to use the diffserv4 model a lot to > manage videoconferencing better. Are you sure? Video gets up to 50% of shaper capacity at = elevated priority.. this is not doing the required enforcement to keep = NQB rate low... > As for the CS0-CS7 precedence model inc cake, we have declared that > obsolete in the code, and wherever NQB falls into it, great. And the > diffserv8, I don=C2=B4t know. >=20 > Anyway, does that work for everyone? Not for me, as you know I prefer to treat NQB like CS0 for all = classes. >=20 > Part II of this would be a discussion of the various wash modes, but > merely getting the right byte into the right lookup tables after all > this discussion, would be nice. Wash is only a single mode and should stay so, remapping all = DSCPs cake used to steer packets to priority tins to CS0 to not = leak/reveal any of the internal details upstream. Users wanting to = expose NQB to the world, simply do not configure wash or use nowash... I am not sure whether you are thinking in that direction at al = or whether I am just "paranoid" but washing most DSCPs but retain NQB = would IMHO a disservice to cake's users. If you believe such a = functionality is needed, it should be configurable which DSCPs to retain = and most importantly it should not be called wash to avoid confusion = with the current behavior, please. Regards Sebastian P.S.: The bigger issue is that NQB's design goal is a shallow buffered = queue where the side effects of that shallow buffers is hoped to = discipline the NQB users not to try to game the system. While I = generally believe this not to work, this is not what cake is going to = offer, NQB flows will really only be bound by the capacity share. And = e.g. a single NQB flow n diffserv4 (with no other non-BestEffort = traffic, will be able to hog >=3D 50% of the total link capacity. That = seems problematic... (this is also true for other DSCPs mapping into = these priority tiers, but these are rarely exercised by applications = without active user intervention in the first place).