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 6134A3CB35; Thu, 9 Jun 2022 14:30:26 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1654799422; bh=yD3SR/Vp2/txLZTFy6Zp5K5Dxec38SV2QdChK3w8pK4=; h=X-UI-Sender-Class:Subject:From:In-Reply-To:Date:Cc:References:To; b=KC5MCCIIpa4aAUZ3ZTkpDQN/f0+MJpX2Ol8CRiM9A2N1fxbyEwjrKnKaWSVnAQkPU kVVd66lRA8bVIW9D4T/CWQsHoqrJaQFq8rxLp8Hgpa9NA5FAV4td01I4zN0CEyOi2T iEW8bKjAtCo/+aX9eUV0b7VFX4nrkacPxCkvzXrc= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from smtpclient.apple ([77.3.152.241]) by mail.gmx.net (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1Mxm3Q-1np6A40PQk-00zBgV; Thu, 09 Jun 2022 20:30:22 +0200 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.100.31\)) From: Sebastian Moeller In-Reply-To: Date: Thu, 9 Jun 2022 20:30:21 +0200 Cc: bloat , rpm@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: References: To: Stuart Cheshire X-Mailer: Apple Mail (2.3696.100.31) X-Provags-ID: V03:K1:Y5ly1LEucyvUnC7l6CDFg/DBOz77LB021UtkyILwg2Oz4aC4cme Ghv/34Q74/UfdFBYwV+Zf6y5exCl/ZDtkqCnFklbqVZ9J7BJYC7cIpBb5Z17GU712F4o/nE lDKnsfOwX6oK4793nT3IUKKrF93tdx72o140nn7o4q5JnuMDfqGzRVfDA8HtAF1vbe/KKaB P0Dfn/4cc+sDhAal2WwrA== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:RXf9nyCv0fU=:s9V1GEiGELXd8qtwof/hAN g+zQynjNLZZe4+IEWVz1DJoPUa49RblpBcwi3JR8su1rjVBuf9PlwF9qWh3GwKRJceDQsSxXv q04zOeGlUH+aDA5zqcMdtlRqH0LtXTRhpGEf+25aFQ/CsVGmKWxRVDzhb4pt0Ab2kY/UhcqSp dgBhosg38YBpMioQIgWScRetY1hYPvGFWoTuWPmfRKV5QcAUjsQIiCKzkvUrkII+fGIB7QHgc ecjOxEPcd4XKUrFUhZsrwEkX1r3xtxowDXyJeObVjwHvl0tkZDap9epfZdJ79F+xY8ifXdYFV mboz49+Gu+JbGt3yei+jqo51rL7nKNNbshtmruDWdBvC3g4NVxUgmhtVSYi3nVKa01d34PIT6 ewVMy9eg8JfTXqGkXpbgdsBQ+fltxfeu4wZONHz4tCTiw/IzLoiRfZybCV8746CaK0GAUMT8/ h2igZZEVRlIcFQK2vXeh+MRw2wf8vPc9yr7XkZZ7rI/sAeNJD4RiQDeShL+jZUuX4Utq9SIhh J3dZ/xmlqtZOW2NvFidw6MjGcwDFYlme3Lo+LshVfpaRmzQQVaHE64FcIMze5DzZvoZU9SZ6i 1xOjyZLboeA5Y6cOMjKfi7b5QIRbHUDni3hLPh6jrwcSzbh6MIwjVijhuxJxGHZVCpB7kx/Rh 68FQac/Ty4/l34B0yMn+XS8ccAd1vA9ScVdQX4JAXQ1QVcGEsStHi/TtEds5uiOqfTpj+DjXt FIBY2vZ7KFxJLyjHjXE1SdbblixD+FSfA5YlQwTEvxmCHNqDRlP1njVJUXckjso5VBVsrLPQ0 VBbg1fplnMV8BPrhfVOnWFGJ9VDpL0olA70AHl9Zea8yUuz003y8OH+I4QXFNas1R4mfCw+SV UV9Ij3mOktxxBvVUTdDzELXLAeW43kG4M19u4XCbm67F6JCPFwDQ9cLw0bAAorn69UpLWp+n7 9W6o3yvixohepNQdP0hxobx1YPN7dgRiaHVHcbBzJsog1yJtBKSp7DONzrMeu5rjjwysmD4Kw 7OvhvjLO2+C7lkXtQKsjgWAREQxkd/wnVG8yUGN035/xnXhnbepe4ufveJi8vz7FtE/Uo/cZc o6oKWgiaVN3rCMCWgsXyijIyaay7tl3k677McD310/E4J0rYMlwzIsZJQ== Subject: Re: [Bloat] Apple WWDC 2022 presentation on L4S now available 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: Thu, 09 Jun 2022 18:30:26 -0000 Nice informative video! But: "Comparing classic queuing versus L4S shows that there is a massive = reduction in round trip time with L4S. This is the primary reason for the dramatic improvement in my = screen-sharing experience." Seems unhelpful to me. As far as I can tell what is compared here is an = oversized FIFO (multiple seconds in a local Network queueing delay) with = L4S' L-queue. This hence demonstrates that AQM is better than no AQM, = but seems interprets the result as argument for L4S' being a good AQM. = It would be highly interesting to see how the same traffic would behave = if "classic queuing" was any other AQM. Or even the "C-queue" of L4S = which (while not an optimized AQM*) should also push the latency from = painful multiple seconds into the dozens of milliseconds range that = would be fully acceptable (and might not even be noticed). Or even just = an FQ scheduler without AQM... The other issue is that currently no L4S AQM are deployed, so I miss the = "deploy L4S AQM at your network nodes" advice that seems essential for = L4S actually helping**. I understand that this video is not intended as a contribution to the = academic discussion about relative merits of different AQM approaches, = but still ... Regards Sebastian *) After all it needs to be bad enough to make the L-queue shine in = comparison, hence the surprisingly high reference target delays for e.g. = DualQ's C-queue PIE implementation, with its actively misleading = justification from misinterpreted/misunderstood latency data**... **) scraped from a blog post intended to show-case how the RIPE ATLAS = network can be used for real experiments, and not a peer reviewed study = of typical RTTs between endusers and "the internet". =20 > On Jun 9, 2022, at 18:18, Stuart Cheshire via Bloat = wrote: >=20 > Our colleague Vidhi Goel recorded an excellent Apple developer = conference video =E2=80=9CReduce networking delays for a more responsive = app=E2=80=9D, which talks about bufferbloat and L4S. >=20 > >=20 > Stuart Cheshire >=20 > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat