Re: [Ntp] Roughtime time resolution and timestamp format

Christopher Patton <chrispatton@gmail.com> Tue, 02 April 2024 20:16 UTC

Return-Path: <chrispatton@gmail.com>
X-Original-To: ntp@ietfa.amsl.com
Delivered-To: ntp@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id DF993C14F5F3 for <ntp@ietfa.amsl.com>; Tue, 2 Apr 2024 13:16:53 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.097
X-Spam-Level:
X-Spam-Status: No, score=-2.097 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_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_ZEN_BLOCKED_OPENDNS=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 ([50.223.129.194]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9WIICT9-7Iz5 for <ntp@ietfa.amsl.com>; Tue, 2 Apr 2024 13:16:53 -0700 (PDT)
Received: from mail-lf1-x12b.google.com (mail-lf1-x12b.google.com [IPv6:2a00:1450:4864:20::12b]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 87F90C14F5ED for <ntp@ietf.org>; Tue, 2 Apr 2024 13:16:53 -0700 (PDT)
Received: by mail-lf1-x12b.google.com with SMTP id 2adb3069b0e04-513d23be0b6so6175813e87.0 for <ntp@ietf.org>; Tue, 02 Apr 2024 13:16:53 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1712089011; x=1712693811; darn=ietf.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=B79G9/pKanf4f4sQprLm3gVdsmT2lVMzS1CuA0W1v/w=; b=E3tove1XaPBWkqFaqHHlE07GFWcY/DMXbfibB9Z2luDFmaAei9SQHTm657GhDMz6XG mxu7jHGxAfL7uPgqVG5J/akuXxWLyEVXG0GAGVbwaRfs4Pl/opfCxA8RSJNXLZNkd+v2 ZfuN7CdDenY42a1AmoY+2YXP+dH58W0batanfYTPcEuSZReJsidhJmsCsfDZF2QTr/Zv 9H3qH43kdVlrCiiSy4Sanh6gqDZ8K44K0nzubXNFNTavOQUFIdO1rkdpexmsnAo0+fSk 3ae12C32nak0yZbeRIwmiUQ5pZcwAPaYup9Cw2LOmCUW3R6bG3cmm8DKV5tPU5N8E8ZO PERw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712089011; x=1712693811; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=B79G9/pKanf4f4sQprLm3gVdsmT2lVMzS1CuA0W1v/w=; b=BAZc/zpiPyL7xpfIZp9oNGCUX6cXmZGcuDxpEphKKrm7he74+FfdwnGZk1jXauVcXU iNNEzkSDYOZmXZxx7YiHxEt8TWN53XlPjN4Ok01mB2kW36ZVTD34ivKAFhjGs/Rv345Y BmHBYbfFUeYJ8sjQi7ezpyAa3lqT1muf/tIoZsCleUL/xK7w8eaP6s0spwkPHUacMDko 10GRekj4/EMuJ61jF9V/nT9ELnqtkTTMH7D4+3XWupMvuMZMrDru9NhUxV0HZNqktApe q/usu3lzOWJbAmXBwsRL2ALLKC3PdE1H00L4ETosGISX7DfeJUdx5TW2XfzUIXjUWMg2 mZpg==
X-Gm-Message-State: AOJu0YyC4jOouvvAwza69+2Bkt8HJdIJ45Bji5y+Owqq91zmKchUFm9f fi5W2ROiUZVo7Agj98ryfXrHswXVRTufqgI/ZrJNJYgxseyiBNVCujmECqTdYeZDOQ6iGHIKcmS OpmI3XKL277j8CFYKnEM1u3BeOkNKFx6+
X-Google-Smtp-Source: AGHT+IHH+cMrSaW6JIPe+RxB9fQf3vZ8M9FUWTukE3PSX1o7Opcub4qx5VUFzudTrVLIfYCnE4BzSNFv3Goo3o8AczQ=
X-Received: by 2002:a2e:9914:0:b0:2d4:6aba:f1a9 with SMTP id v20-20020a2e9914000000b002d46abaf1a9mr9631454lji.40.1712089010761; Tue, 02 Apr 2024 13:16:50 -0700 (PDT)
MIME-Version: 1.0
References: <ba509b9a-0e35-4530-a3d9-673ed0ae5c5c@dansarie.se>
In-Reply-To: <ba509b9a-0e35-4530-a3d9-673ed0ae5c5c@dansarie.se>
From: Christopher Patton <chrispatton@gmail.com>
Date: Tue, 02 Apr 2024 13:16:38 -0700
Message-ID: <CACLV2m5rbc8hpD4YMu1VE0Hq8iQjzMFvM5vzwQbasXZSYjOukg@mail.gmail.com>
To: Marcus Dansarie <marcus@dansarie.se>
Cc: "ntp@ietf.org" <ntp@ietf.org>
Content-Type: multipart/alternative; boundary="0000000000004f7644061522c90b"
Archived-At: <https://mailarchive.ietf.org/arch/msg/ntp/LQO5GdE1EkwF8anurSL_xtQVpoA>
Subject: Re: [Ntp] Roughtime time resolution and timestamp format
X-BeenThere: ntp@ietf.org
X-Mailman-Version: 2.1.39
Precedence: list
List-Id: Network Time Protocol <ntp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ntp>, <mailto:ntp-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ntp/>
List-Post: <mailto:ntp@ietf.org>
List-Help: <mailto:ntp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ntp>, <mailto:ntp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 02 Apr 2024 20:16:54 -0000

Hey Marcus,

* What resolution of time and time accuracy should Roughtime use?
>

I think seconds is sufficient resolution for all applications I'm aware of.
We could go for higher resolution I suppose, but we're never going to be as
good as NTP. In fact, I sort of like that Roughtime is less precise by
design: it's more clear to users that it is definitely not an adequate
substitute for NTP.


> * What should the Roughtime timestamp format look like?
>

I'm Roughtime, not a subject matter expert on clock synchronization, so I
don't fully appreciate the complexity that Unix time creates. However, it
seems to me that Unix time is the most developer-friendly choice, which
makes it a good choice if you don't care about perfect synchronization.

Chris P.