Re: [Dtls-iot] Spencer Dawkins' Yes on draft-ietf-dice-profile-16: (with COMMENT)

"FOSSATI, Thomas (Thomas)" <thomas.fossati@alcatel-lucent.com> Wed, 30 September 2015 21:28 UTC

Return-Path: <thomas.fossati@alcatel-lucent.com>
X-Original-To: dtls-iot@ietfa.amsl.com
Delivered-To: dtls-iot@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 5D5C21A90E6; Wed, 30 Sep 2015 14:28:35 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -6.91
X-Spam-Level:
X-Spam-Status: No, score=-6.91 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, T_RP_MATCHES_RCVD=-0.01] autolearn=ham
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 ft0ue_9cU07o; Wed, 30 Sep 2015 14:28:26 -0700 (PDT)
Received: from smtp-fr.alcatel-lucent.com (fr-hpgre-esg-01.alcatel-lucent.com [135.245.210.22]) (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 968411A90DA; Wed, 30 Sep 2015 14:28:17 -0700 (PDT)
Received: from fr711usmtp1.zeu.alcatel-lucent.com (unknown [135.239.2.122]) by Websense Email Security Gateway with ESMTPS id 1D8CBEE7D4039; Wed, 30 Sep 2015 21:28:12 +0000 (GMT)
Received: from FR711WXCHHUB01.zeu.alcatel-lucent.com (fr711wxchhub01.zeu.alcatel-lucent.com [135.239.2.111]) by fr711usmtp1.zeu.alcatel-lucent.com (GMO) with ESMTP id t8ULSFR6024634 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Wed, 30 Sep 2015 23:28:15 +0200
Received: from FR711WXCHMBA08.zeu.alcatel-lucent.com ([169.254.4.234]) by FR711WXCHHUB01.zeu.alcatel-lucent.com ([135.239.2.111]) with mapi id 14.03.0195.001; Wed, 30 Sep 2015 23:28:15 +0200
From: "FOSSATI, Thomas (Thomas)" <thomas.fossati@alcatel-lucent.com>
To: Spencer Dawkins <spencerdawkins.ietf@gmail.com>, The IESG <iesg@ietf.org>
Thread-Topic: [Dtls-iot] Spencer Dawkins' Yes on draft-ietf-dice-profile-16: (with COMMENT)
Thread-Index: AQHQ+8bq/K8Gy1LU70ap60U7JV8CFQ==
Date: Wed, 30 Sep 2015 21:28:14 +0000
Message-ID: <D231FF3B.363DC%thomas.fossati@alcatel-lucent.com>
References: <20150930180453.20560.45039.idtracker@ietfa.amsl.com>
In-Reply-To: <20150930180453.20560.45039.idtracker@ietfa.amsl.com>
Accept-Language: en-GB, en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
user-agent: Microsoft-MacOutlook/14.5.5.150821
x-originating-ip: [135.239.27.41]
Content-Type: text/plain; charset="us-ascii"
Content-ID: <046993E5EEF7D64F82FF023A21482A51@exchange.lucent.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Archived-At: <http://mailarchive.ietf.org/arch/msg/dtls-iot/y21k21sl2malh4u42Qsa3jkjzZ4>
Cc: "zach.shelby@arm.com" <zach.shelby@arm.com>, "dtls-iot@ietf.org" <dtls-iot@ietf.org>, "dice-chairs@ietf.org" <dice-chairs@ietf.org>, "draft-ietf-dice-profile.shepherd@ietf.org" <draft-ietf-dice-profile.shepherd@ietf.org>, "draft-ietf-dice-profile@ietf.org" <draft-ietf-dice-profile@ietf.org>, "draft-ietf-dice-profile.ad@ietf.org" <draft-ietf-dice-profile.ad@ietf.org>
Subject: Re: [Dtls-iot] Spencer Dawkins' Yes on draft-ietf-dice-profile-16: (with COMMENT)
X-BeenThere: dtls-iot@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DTLS for IoT discussion list <dtls-iot.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dtls-iot>, <mailto:dtls-iot-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dtls-iot/>
List-Post: <mailto:dtls-iot@ietf.org>
List-Help: <mailto:dtls-iot-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dtls-iot>, <mailto:dtls-iot-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 30 Sep 2015 21:28:35 -0000

Hi Spencer,

Thanks for your comments.  Quick reply on this one:

On 30/09/2015 19:04, "dtls-iot on behalf of Spencer Dawkins"
<dtls-iot-bounces@ietf.org on behalf of spencerdawkins.ietf@gmail.com>;
wrote:
>
>In this text,
>
>   On the other hand, the way DTLS handles
>   retransmission, which is per-flight instead of per-segment, tends to
>   interact poorly with low bandwidth networks.
>   
>I'm assuming you are using "per-flight" in the
>https://tools.ietf.org/html/rfc5681 sense of the term ("FLIGHT SIZE: The
>amount of data that has been sent but not yet cumulatively
>acknowledged"), but that's somewhat obscure, especially outside of TSV,
>and there's no definition or reference for it in this document. Perhaps
>you could say something like
>
>   On the other hand, DTLS handles loss by retransmitting the
>   entire amount of data that has been sent but has not been
>   cumulatively acknowledged, and this tends to
>   interact poorly with low bandwidth networks.

The term "flight" has a precise connotation in DTSL (see
https://tools.ietf.org/html/rfc6347#section-4.2.4) which is what we imply
here.

In the paragraph just above the one you've quoted, we reference section
4.2.4 of RFC 6347 which is where the term is originally introduced; so,
although implicitly, we provide the context.

I agree this is not perfect, but it's not easy to guess what the reader
knows already, what his/her mental filters are, etc, so I'm not sure what
we could do to make the text better/unambiguous?

Cheers, t