From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) (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 C3E0A3CB3E for ; Sun, 21 Jul 2019 12:13:11 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1563725542; bh=i1TewBtxvYpvcByNEzJ3PE1jbQPQTp90One9amQFrMk=; h=X-UI-Sender-Class:Subject:From:In-Reply-To:Date:Cc:References:To; b=aoAUTmHz3+OvWmIFT8lQuny77Z3kQavsI4d/2CB78cS8SSgZVhCSGSlqDuNWwo8CD 1sl2aT4ntWolXmxv8Nm9+ZTQ9Zy54uqA4S1UT/mRJEurkjrSxV7GkRBbsaSti4qOx+ zwT26l9CPH9FXGwvuvQKpE8+ImpX23x8IjBmDps0= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from hms-beagle2.lan ([77.185.149.150]) by mail.gmx.com (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MhU9j-1iKjW11NY3-00ecqj; Sun, 21 Jul 2019 18:12:22 +0200 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) From: Sebastian Moeller In-Reply-To: Date: Sun, 21 Jul 2019 18:12:20 +0200 Cc: Bob Briscoe , "De Schepper, Koen (Nokia - BE/Antwerp)" , "Black, David" , "ecn-sane@lists.bufferbloat.net" , "tsvwg@ietf.org" , Dave Taht Content-Transfer-Encoding: quoted-printable Message-Id: References: <364514D5-07F2-4388-A2CD-35ED1AE38405@akamai.com> <1238A446-6E05-4A55-8B3B-878C8F39FC75@gmail.com> <17B33B39-D25A-432C-9037-3A4835CCC0E1@gmail.com> <52F85CFC-B7CF-4C7A-88B8-AE0879B3CCFE@gmail.com> <87ef2myqzv.fsf@taht.net> <803D9CA8-220E-4F98-9B8E-6CE2916C3100@gmail.com> <0079BC6B-4792-48ED-90D3-D9A69407F316@gmx.de> <22af0671-fdd0-0953-fc96-55b34beb0be9@bobbriscoe.net> To: Jonathan Morton X-Mailer: Apple Mail (2.3445.104.11) X-Provags-ID: V03:K1:gRqczlIqh/RMUYkZ3cy1NzC0ntK9xw2vRBhVGn8JbxSItCaATBP P9PTXzPQVXjH8TI4FSg+Gx1PTdLD4JU3WLCErko0ayTL3h0IMwPc9xZ24XjdqXgrOfTs07/ 3vLdqIPotDomewdqw2aWtZrUJaqETxgiD6gARQ0JZ3vWlaZl2OK5ZM7U/MLUen8Wx9V+IdG UUwZXSxJVWR5IzB4t6iHg== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:1q9mTFDKcwY=:WCMzOOa2+d71NpgLreCT8f NLYi79e2yNGI9Sdr0v5OyUvcEIONkhhmBIsUR2SH6fdRf4unxTjXIRCCTwP54S+OQpRxCr4v+ Wjf27Y7PkGuLs0GckD+WJF/lMN4Q4VQQwXZg7IkTmEquGiErZ13VqEpwhGZL30UVt5ccOcg4j 74srXd7R9hX8yrPAx9sI2US+rWOnCVox48A8ZYmwlxkgritFOpdtzu+3O8yjwBsWaQWRP0GQ8 zdrCEA8AoDVrC6Qx2lXnda9Haz99DjxLDz1cD335/JTvCQyEytMloYJsWnRzLmc73nu2RJ4Jl m03sKKpHN7VAbbRLPCCBkvTkIlcg/MoBHknq9vPug0ikZDBvQA5tJQfY1WakO6zt1fFpV4kxy wnzwwqpzlVPQopYZZN99N7pU/gS/NAAhmBkxTeRETeO+sY5GTYP1bc5cDUcWRyKiT8Z/srN0b wO3Bg5QSBhD2Ugpy7JKvUkHAl7QfkKawW8VEFL+kKxaIhlIoqR8vmouj5bgUMxDo5FNBgf3Ff GdiSzS40RS1HzvvDaYyla/jZmtVqw/Gph/l1cw+I4ZwdcuQi8vw+BT2hmjh9L1kjTq1Fti2G7 oAaOqD61o26+nusZdd/nm2SH8aEvI42t4XiyhMo5fWjBLHJddtT00teQ8xxx8f+Cb+0MzgeCK 0nTiS21gt/lvf3uvdnxQg40E4ENfFk354fMax3pAHzvnDzz1jx1jnh6ncmhYWyo19eNkBh5Oj kfBCYfsROBrhrBnbA3ROd5Hbg34pu7Jsd2qu/fhJg4fKj2i5F9PXVdCs+V5jDD/qcTdKQjycG HTZFKA9VWOoZXd/7WDFmuxA6IhHrAkiZOwzSh2y57Xx3bXDOPczcagOA+ctqfJmAwXuKtjcne 0XBUHpesuMHw8BKbfC8OjVDtcM1wJrzI5p5Dd7X/OwvtMi8t7zBh7aGhq6imp0ONO25oL9z9S coMxdgsYeITURhHbxQtoz9fgWqfJUf/GmH272kZKtFbG1B1mZz+F5YDnfCxiu80xa1jNRLkSm 7982p7rEJOCMIvGHNq++gcPeAtOggVZQPYJwEOeVHg37DrVa6ScQ7yjzw/uRBrkyMNcKs6s+h 48FvwPvS0q7Y7Y= Subject: Re: [Ecn-sane] [tsvwg] Comments on L4S drafts X-BeenThere: ecn-sane@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussion of explicit congestion notification's impact on the Internet List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 21 Jul 2019 16:13:12 -0000 Dear Jonathan, many thanks, these are exactly the tests I am curious about. Excellent = work, now I am super curious about the results! > On Jul 21, 2019, at 18:00, Jonathan Morton = wrote: >=20 >> On 21 Jul, 2019, at 7:53 am, Bob Briscoe wrote: >>=20 >> Both teams brought their testbeds, and as of yesterday evening, Koen = and Pete Heist had put the two together and started the tests Jonathan = proposed. Usual problems: latest Linux kernel being used has introduced = a bug, so need to wind back. But progressing. >>=20 >> Nonetheless, altho it's included in the tests, I don't see the = particular concern with this 'Cake' scenario. How can "L4S flows crowd = out more reactive RFC3168 flows" in "an RFC3168-compliant FQ-AQM". = Whenever it would be happening, FQ would prevent it. >>=20 >> To ensure we're not continually being blown into the weeds, I thought = the /only/ concern was about RFC3168-compliant /single-queue/ AQMs. >=20 > I drew up a list of five network topologies to test, each with the SCE = set of tests and tools, but using mostly L4S network components and = focused on L4S performance and robustness. >=20 >=20 > 1: L4S sender -> L4S middlebox (bottleneck) -> L4S receiver. >=20 > This is simply a sanity check to make sure the tools worked. Actually = we fell over even at this stage yesterday, because we discovered = problems in the system Bob and Koen had brought along to demo. These = may or may not be improved today; we'll see. >=20 >=20 > 2: L4S sender -> FQ-AQM middlebox (bottleneck) -> L4S middlebox -> L4S = receiver. >=20 > This is the most favourable-to-L4S topology that incorporates a = non-L4S component that we could easily come up with, and therefore . = Apparently the L4S folks are also relatively unfamiliar with Codel, = which is now the most widely deployed AQM in the world, and this would = help to validate that L4S transports respond reasonably to it. >=20 >=20 > 3: L4S sender -> single-AQM middlebox (bottleneck) -> L4S middlebox -> = L4S receiver. >=20 > This is the topology of most concern, and is obtained from topology 2 = by simply changing a parameter on our middlebox. >=20 >=20 > 4: L4S sender -> ECT(1) mangler -> L4S middlebox (bottleneck) -> L4S = receiver. >=20 > Exploring what happens if an adversary tries to game the system. We = could also try an ECT(0) mangler or a Not-ECT mangler, in the same = spirit. >=20 >=20 > 5: L4S sender -> L4S middlebox (bottleneck 1) -> Dumb FIFO (bottleneck = 2) -> FQ-AQM middlebox (bottleneck 3) -> L4S receiver. >=20 > This is Sebastian's scenario. We did have some discussion yesterday = about the propensity of existing senders to produce line-rate bursts = occasionally, and the way these bursts could collect in *all* of the = queues at successively decreasing bottlenecks. This is a test which = explores that scenario and measures its effects, and is highly relevant = to best consumer practice on today's Internet. double plus! >=20 >=20 > Naturally, we have tried the equivalent of most of the above scenarios = on our SCE testbed already. The only one we haven't explicitly tried = out is #5; I think we'd need to use all of Pete's APUs plus at least one = of my machines to set it up, and we were too tired for that last night. Thanks for doing this! Best Regards Sebastian >=20 > - Jonathan Morton