IETF Logo Mail Archive

Re: [tsvwg] Robert Wilton's No Objection on draft-ietf-tsvwg-datagram-plpmtud-19: (with COMMENT)

Jonathan Morton <chromatix99@gmail.com> Fri, 10 April 2020 14:02 UTC

Return-Path: <chromatix99@gmail.com>
X-Original-To: tsvwg@ietfa.amsl.com
Delivered-To: tsvwg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 0ED7B3A0B19; Fri, 10 Apr 2020 07:02:06 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.849
X-Spam-Level:
X-Spam-Status: No, score=-1.849 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
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 0VTvgbJsNbJK; Fri, 10 Apr 2020 07:02:04 -0700 (PDT)
Received: from mail-lj1-x22c.google.com (mail-lj1-x22c.google.com [IPv6:2a00:1450:4864:20::22c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 835A43A0B10; Fri, 10 Apr 2020 07:02:04 -0700 (PDT)
Received: by mail-lj1-x22c.google.com with SMTP id 142so2038638ljj.7; Fri, 10 Apr 2020 07:02:04 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=kptMQauUsNGxp2oS9fHnkTgQvVyq5aDje9yFo4gng2k=; b=F0ceudc/bFiG1KSmJWGZI8KtJUKhAy/VZY+dUwEG8GVCidqp964M8cJ++VA8+ZRYhk Gix8iKjU0kPq/kLH/qtzbdGEMF7dtG2j9UK2xljJYL2TXHjLwxGlmxva7lnztkwugpuS nOuyyyEDSoNXbT7+IOsi/PlA2b4pFTMkz51Ed+KUp9oTYGt3AMqRGPVcQDKdcHxoE8sH IkzsdwgJ7p2P+FZ0/B8RJ1J0a1m4enUzJ0Xu7+mtdoiXMh+jgj/OMUxpCpGq1UYdqHdX kzWyMQkBS8BjdnkeJtL01T3BIKs3riOgONhMii1rJOXku1hV7O34L+UErcNkDogakabJ GEEg==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=kptMQauUsNGxp2oS9fHnkTgQvVyq5aDje9yFo4gng2k=; b=YRcs3qhCwtVfm7lad3INjo9PT50QkECcjCgWTRqSsFdGHw14P+JQFQZSUpdwQH665R NNT9oJxFZ3jPcpwqN3PVpMtPccZ0vrGrZUVcwnYiaZT1DlIiLlNO002pQ2/Hu+mKoopu dnA+WjbUUuVnAuUbzHr5h672doqvnWCC91PrR0fPIV2F+ID8wt1lPGQFD1LXFRSkhlck +GwzIHygh179iphV8Fp5mvL0+kyo74Ncx98CoNI5p5TtAwZPTk+HTLSz9mvADyxf2Fwg HJRavBQEeXudIGHEpr0dQOhGP2q5dFqisaTt270YHqqIcPi4Hwp9x/CqcBADKQH3XNY9 hEXg==
X-Gm-Message-State: AGi0PuZ+GQqkD9PTjtGVeu8WGExqJjIGTxy42+uxssTr/Fv8pSYxw9Ej It6g+/qLeCSuLlSUY3apxPw=
X-Google-Smtp-Source: APiQypISTX/gaWlS4mntFGR/eBkDZWIv39KzjVj5KOkDqlTEKArIhjWbehSr3m7XMs49Z4o5KhatoA==
X-Received: by 2002:a2e:854e:: with SMTP id u14mr3046656ljj.95.1586527322684; Fri, 10 Apr 2020 07:02:02 -0700 (PDT)
Received: from jonathartonsmbp.lan (83-245-250-250-nat-p.elisa-mobile.fi. [83.245.250.250]) by smtp.gmail.com with ESMTPSA id l20sm1133651lji.74.2020.04.10.07.02.01 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 10 Apr 2020 07:02:01 -0700 (PDT)
Content-Type: text/plain; charset="us-ascii"
Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\))
From: Jonathan Morton <chromatix99@gmail.com>
In-Reply-To: <CAKKJt-dU2Ydj_puXrUzsa-R4tvCd_894JsMHmSQsDTXY+UfJ9g@mail.gmail.com>
Date: Fri, 10 Apr 2020 17:02:00 +0300
Cc: "Rodney W. Grimes" <ietf@gndrsh.dnsmgr.net>, Gorry Fairhurst <gorry@erg.abdn.ac.uk>, "tsvwg@ietf.org" <tsvwg@ietf.org>, Robert Wilton <rwilton@cisco.com>, "draft-ietf-tsvwg-datagram-plpmtud@ietf.org" <draft-ietf-tsvwg-datagram-plpmtud@ietf.org>, "tsvwg-chairs@ietf.org" <tsvwg-chairs@ietf.org>, The IESG <iesg@ietf.org>
Content-Transfer-Encoding: quoted-printable
Message-Id: <AA4D3443-78CC-408E-8EF7-7CA556E34C6A@gmail.com>
References: <b7a852db-0afe-5fd1-365b-aecdc474a78a@erg.abdn.ac.uk> <202004100512.03A5CNH6012551@gndrsh.dnsmgr.net> <CAKKJt-dU2Ydj_puXrUzsa-R4tvCd_894JsMHmSQsDTXY+UfJ9g@mail.gmail.com>
To: Spencer Dawkins at IETF <spencerdawkins.ietf@gmail.com>
X-Mailer: Apple Mail (2.3445.9.1)
Archived-At: <https://mailarchive.ietf.org/arch/msg/tsvwg/H6jn8LW0uofvVzvjw3Znk-zeTC0>
Subject: Re: [tsvwg] Robert Wilton's No Objection on draft-ietf-tsvwg-datagram-plpmtud-19: (with COMMENT)
X-BeenThere: tsvwg@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Transport Area Working Group <tsvwg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tsvwg>, <mailto:tsvwg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tsvwg/>
List-Post: <mailto:tsvwg@ietf.org>
List-Help: <mailto:tsvwg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tsvwg>, <mailto:tsvwg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 10 Apr 2020 14:02:06 -0000

> On 10 Apr, 2020, at 4:38 pm, Spencer Dawkins at IETF <spencerdawkins.ietf@gmail.com> wrote:
> 
> ISTM that asking people to poke at this and report back in MAPRG is an excellent idea. Depending on whether there are still "relatively few MTU values in use" or not, it might then be useful to consider either updating the table of commonly-used values, or saying "binary search will probably work fine now".

In connection with this, it's perhaps worth noting that some applications won't need to establish the precise MTU, only the minimum number of fragments they need to use for their jumbo datagram.

For example, a 10,000 byte IPv4 packet can fit through a 1500-byte MTU path in seven 1446-byte fragments, but not in six 1684-byte fragments.  (The calculation is different for IPv6 due to the larger headers.)  Refining this distinction further only becomes relevant when datagrams of different sizes have to be sent over the same path, or when a stream transport is involved so that testing specific divisors is not helpful.

So a variety of search algorithms may be useful in different circumstances.

 - Jonathan Morton

v2.23.0 | Report a Bug | By Email