IETF Logo Mail Archive

Re: [tsvwg] Adoption call: draft-fairhurst-tsvwg-datagram-plpmtud-02 to end 10th January 2018

Christian Huitema <huitema@huitema.net> Wed, 10 January 2018 18:23 UTC

Return-Path: <huitema@huitema.net>
X-Original-To: quic@ietfa.amsl.com
Delivered-To: quic@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id BEF3E127871 for <quic@ietfa.amsl.com>; Wed, 10 Jan 2018 10:23:04 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.601
X-Spam-Level:
X-Spam-Status: No, score=-2.601 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id XKjkTufNfHTm for <quic@ietfa.amsl.com>; Wed, 10 Jan 2018 10:23:02 -0800 (PST)
Received: from mx43-out1.antispamcloud.com (mx43-out1.antispamcloud.com [138.201.61.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 9405512D77E for <quic@ietf.org>; Wed, 10 Jan 2018 10:23:02 -0800 (PST)
Received: from xsmtp05.mail2web.com ([168.144.250.245]) by mx43.antispamcloud.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.89) (envelope-from <huitema@huitema.net>) id 1eZL1g-0001kg-JV for quic@ietf.org; Wed, 10 Jan 2018 19:23:01 +0100
Received: from [10.5.2.31] (helo=xmail09.myhosting.com) by xsmtp05.mail2web.com with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.63) (envelope-from <huitema@huitema.net>) id 1eZL1b-0007NM-D6 for quic@ietf.org; Wed, 10 Jan 2018 13:22:58 -0500
Received: (qmail 9432 invoked from network); 10 Jan 2018 18:22:53 -0000
Received: from unknown (HELO [192.168.200.65]) (Authenticated-user:_huitema@huitema.net@[72.235.171.77]) (envelope-sender <huitema@huitema.net>) by xmail09.myhosting.com (qmail-ldap-1.03) with ESMTPA for <David.Black@dell.com>; 10 Jan 2018 18:22:52 -0000
Content-Type: text/plain; charset="us-ascii"
Mime-Version: 1.0 (1.0)
From: Christian Huitema <huitema@huitema.net>
X-Mailer: iPhone Mail (15C153)
In-Reply-To: <5A563390.8050403@erg.abdn.ac.uk>
Date: Wed, 10 Jan 2018 08:22:50 -1000
Cc: "Eggert, Lars" <lars@netapp.com>, "Black, David" <David.Black@dell.com>, "tsvwg@ietf.org" <tsvwg@ietf.org>, QUIC WG <quic@ietf.org>
Content-Transfer-Encoding: quoted-printable
Message-Id: <4123465B-CFE2-410E-BE1D-E09DC189F280@huitema.net>
References: <CE03DB3D7B45C245BCA0D243277949362FE164EB@MX307CL04.corp.emc.com> <9837331A-76DF-4137-9612-CC653E869553@netapp.com> <5A563390.8050403@erg.abdn.ac.uk>
To: gorry@erg.abdn.ac.uk
Subject: Re: [tsvwg] Adoption call: draft-fairhurst-tsvwg-datagram-plpmtud-02 to end 10th January 2018
X-Originating-IP: 168.144.250.245
X-AntiSpamCloud-Domain: xsmtpout.mail2web.com
X-AntiSpamCloud-Username: 168.144.250.0/24
Authentication-Results: antispamcloud.com; auth=pass smtp.auth=168.144.250.0/24@xsmtpout.mail2web.com
X-AntiSpamCloud-Outgoing-Class: unsure
X-AntiSpamCloud-Outgoing-Evidence: Combined (0.17)
X-Recommended-Action: accept
X-Filter-ID: EX5BVjFpneJeBchSMxfU5hBLWOU3oxkI4vPhZr/z+MQXv9krsgRhBn0ayn6qsUc7A2kcKDr1fzRm ksYYe0sWHrgNzB/4Jkrw1eDLcif59fsKNPILOWNIp50KNu32/z0EB98yDTitFWvbHwz9vKZpmxBf ggn8Frespz1KxArpwUw8uEFOG92DI83j3LMNDNEdZsQEbaxxISMHgJxrdMdSS4B6hVJPXxgisa+g wkHvC+PVG1YjIrFRKhESMT/tU1Dx+IHaAZrg1ulFniksjLYqZxdG5bOwa1rOgT+89+/XFrGt2tce crpXRY6fm8RXptyzavERpop5LF7RavHozgbn9XzprFRbpFQTOcEGeQOY3IcDlgJpEbxunV7tCPNi PQvHQpVRoYcix47lJTuKsG8TgnDHFRDF834rtLc6Wv9Yj+vBPX9bzGJi0ycLbiOUDEySIK/1NH5T HMtlYvyHAYGOGheVSH7cGoIH3Vd41lbD31XsxRC3Cl5agFgis4e3pTrPzFy2BMVafZkKGCe45ASM DXlktEzRL2aN64ozk8iKu6gHmFDqewO9xyOqCYO8P1aHuJ+q0VAdWduuFNAGSPDW/D0UF36LWvas gj4e2T8BuA1dHghQC//pO9KiygTP+bGFirtlAtdsrBTAcAoY5WeLmsibYT4C2qF2lnc18bVJn64Q cGNbbUfVtyF2zetYzSLaI+V/fXqHoTlLNtJsRIkQZDwJWw42swm4bO6gacpMpzLdQBUMkAI/PGrN 0+wWmMSTvLpZVaBCgo9IFgw1OrNwYFjI1dRH6f16eQCtvwPkeoxzBkc1CTpvaEJjkrbHF6v+l1Fr MVSE/J/ewUnTj7YP55q9INbyRwqQyVkoHpS/jX2RVYKU9W9tbmVXJBqdHHDm8ZIH36IzEI956ubs TR4WHrFV5oTvAcwA4rM3FkfW8/2B3o0d/ygg1mkxyifBss2L
X-Report-Abuse-To: spam@quarantine5.antispamcloud.com
Archived-At: <https://mailarchive.ietf.org/arch/msg/quic/vlgc8estoY9gvQzowSwLGukRDg0>
X-BeenThere: quic@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: Main mailing list of the IETF QUIC working group <quic.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/quic>, <mailto:quic-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/quic/>
List-Post: <mailto:quic@ietf.org>
List-Help: <mailto:quic-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/quic>, <mailto:quic-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 10 Jan 2018 18:23:05 -0000

> On Jan 10, 2018, at 5:38 AM, Gorry Fairhurst <gorry@erg.abdn.ac.uk> wrote:
> ...
> 
> I suspect someone could use the final method with QUIC - since it's also a UDP-based transport. I don' knopw of anyone planning PMTUD for QUIC - please get in touch if that is on your radar.

The initial packets in QUIC are sent with min IPv6 MTU. During the initial exchange, the nodes send the maximum packet size that they might accept. QUIC does not specify the actual probing algorithm but does specify that PMTU is per path.

Several QUIC implementations do PMTUD already, building simple probes with QUIC's Ping and Padding frames. Probes are then encrypted, and sent as QUIC packets in UDP with segmentation turned off. If the probe packet is acknowledged, the applications know that this much MTU can be sent.

Note the encrypted part. Replacing such mechanisms by a clear text exchange is not desirable.

-- Christian Huitema

v2.23.0 | Report a Bug | By Email