IETF Logo Mail Archive

Re: [TICTOC] [Ntp] WGLC for draft-ietf-ntp-mac

Miroslav Lichvar <mlichvar@redhat.com> Wed, 30 August 2017 09:25 UTC

Return-Path: <mlichvar@redhat.com>
X-Original-To: tictoc@ietfa.amsl.com
Delivered-To: tictoc@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 12444132D44; Wed, 30 Aug 2017 02:25:53 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -6.92
X-Spam-Level:
X-Spam-Status: No, score=-6.92 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01] 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 mmf1N0fVYJZE; Wed, 30 Aug 2017 02:25:51 -0700 (PDT)
Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 6435913235C; Wed, 30 Aug 2017 02:25:51 -0700 (PDT)
Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 07C18800A4; Wed, 30 Aug 2017 09:25:51 +0000 (UTC)
DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 07C18800A4
Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com
Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=mlichvar@redhat.com
Received: from localhost (unknown [10.43.2.117]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 324EA91537; Wed, 30 Aug 2017 09:25:50 +0000 (UTC)
Date: Wed, 30 Aug 2017 11:25:53 +0200
From: Miroslav Lichvar <mlichvar@redhat.com>
To: Karen O'Donoghue <odonoghue@isoc.org>
Cc: "ntp@ietf.org" <ntp@ietf.org>, "tictoc@ietf.org" <tictoc@ietf.org>
Message-ID: <20170830092553.GO11067@localhost>
References: <CF57EAFE-31F0-4ADD-A209-1802DB6CA643@isoc.org>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <CF57EAFE-31F0-4ADD-A209-1802DB6CA643@isoc.org>
User-Agent: Mutt/1.8.0 (2017-02-23)
X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Wed, 30 Aug 2017 09:25:51 +0000 (UTC)
Archived-At: <https://mailarchive.ietf.org/arch/msg/tictoc/-Wf85CHZKZLMRQCh-L_CCLx_Ef8>
Subject: Re: [TICTOC] [Ntp] WGLC for draft-ietf-ntp-mac
X-BeenThere: tictoc@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: Timing over IP Connection and Transfer of Clock BOF <tictoc.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tictoc>, <mailto:tictoc-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tictoc/>
List-Post: <mailto:tictoc@ietf.org>
List-Help: <mailto:tictoc-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tictoc>, <mailto:tictoc-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 30 Aug 2017 09:25:53 -0000

On Wed, Aug 09, 2017 at 04:53:43AM +0000, Karen O'Donoghue wrote:
> This begins a three week working group last call (WGLC) for "Message Authentication Code for the Network Time Protocol"
> https://datatracker.ietf.org/doc/draft-ietf-ntp-mac/

I approve the advancement of the document.

My only suggestion would be remove or modify the sentence: "These are
important considerations for NTP, since latency directly affects
jitter and therefore the accuracy of time synchronization.".

I think it's the stability of the latency what directly affects
jitter, not the latency itself. Transmit timestamps can be corrected
for a stable latency in the MAC calculation to minimize the effect it
has on accuracy. With a shorter latency that becomes less important.

-- 
Miroslav Lichvar

v2.23.0 | Report a Bug | By Email