IETF Logo Mail Archive

Re: [tcpm] Disabling PAWS when possible

Yuchung Cheng <ycheng@google.com> Mon, 25 June 2018 20:29 UTC

Return-Path: <ycheng@google.com>
X-Original-To: tcpm@ietfa.amsl.com
Delivered-To: tcpm@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id F2886130E3E for <tcpm@ietfa.amsl.com>; Mon, 25 Jun 2018 13:29:22 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -17.511
X-Spam-Level:
X-Spam-Status: No, score=-17.511 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, ENV_AND_HDR_SPF_MATCH=-0.5, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, T_DKIMWL_WL_MED=-0.01, USER_IN_DEF_DKIM_WL=-7.5, USER_IN_DEF_SPF_WL=-7.5] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=google.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 FLxZy_T9nXq2 for <tcpm@ietfa.amsl.com>; Mon, 25 Jun 2018 13:29:21 -0700 (PDT)
Received: from mail-it0-x22e.google.com (mail-it0-x22e.google.com [IPv6:2607:f8b0:4001:c0b::22e]) (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 9E3C9130E40 for <tcpm@ietf.org>; Mon, 25 Jun 2018 13:29:21 -0700 (PDT)
Received: by mail-it0-x22e.google.com with SMTP id p185-v6so14252379itp.4 for <tcpm@ietf.org>; Mon, 25 Jun 2018 13:29:21 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=ToRX7PtkpZczpgQtItA0ypwSH7/iNsj56uInTI4ZveM=; b=FF51ytXYzn8hhjzCnp9ctO3CbWXvdzVteff5LoXLdcxs64d7Vcc45ruvnCac2kR16f yClyGvkEEy1JwWsV2wQd68AutMw2Y7R7uIIv+Ioy9TrrdL+DI8JXaFYc3ClNCuY3CYXR DyeQGxMEQzmxzSINKMqUCAzPqnzbCy5nu2iziCYjnTcc5gu2rhol0sE8IwrIXHHIDA4s HOp/qezvkrpTKb8EzbzaQu6RPO88a0Jp1MrmWAdGCz8rriCQTVGX5lI+PKSbtPfZuytu bOj0RwpSCwXm9W+wUaXy8uEvVDDJWXCDoJII/fw322XJ2J9j6YA/ZXhB94Zfog6USoGJ QOLQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=ToRX7PtkpZczpgQtItA0ypwSH7/iNsj56uInTI4ZveM=; b=SCauCWSwxW1Bi77Fbtmg0SZMBH5vAqPYEgAysZV50HkhhRBN9X2MpykJBOtAeXteEr Z3oKqtVWTPREpgdj13pdOILlwbBKQg6qABE6IY8hfPNCKSaeytF66SQDTapb58FT2tmY KVBMgUOWrl5N/bdKdT1mMuY+9uOagU9XN26fxuy7Ouv+WftY6j1LetryvSROYgEYS1jH RSllQcgaIwFJ2iCavKMyIr2ciPE/IBn5mTFzGmTZW4mE6OTaoJjtdqrsnJ3IT4+gacY0 p/JMJuT9xms2MJorRbbLsVaOJd+6bDiqk4s+p9vs6wxnRNa2eGid3wcijQKjpTROuduC ruRA==
X-Gm-Message-State: APt69E2I1TpnvhdEA3XsZ3+rPooFMQhDsoaICitFovjgZk4SGZDm9AzM KXIpTP+xpvO4AgQIxv8d8URqAkloKBZe9g0Re3aMDA==
X-Google-Smtp-Source: AAOMgpeIBTPrR2ZwIGPpRztE5IX2bENWllSop+OSmPC3UKf9o2Zqj65Ntsc/3UXmXgfOHMRMUfeqijl542sMjHxdO10=
X-Received: by 2002:a24:9003:: with SMTP id x3-v6mr2127261itd.139.1529958560647; Mon, 25 Jun 2018 13:29:20 -0700 (PDT)
MIME-Version: 1.0
Received: by 2002:a6b:6b17:0:0:0:0:0 with HTTP; Mon, 25 Jun 2018 13:28:39 -0700 (PDT)
In-Reply-To: <CAO249yfD6na651CSWkzjYRFaEAft9MNyUgjf+X4JNHYJbTCvJw@mail.gmail.com>
References: <CAO249yccvy3c2ytrwOFBAg88X3V4ubbUVzr_Ag3PnrJQOFmckg@mail.gmail.com> <CADVnQynPKzxeFHf_DrGCbQrqcv6U4r=p_3RGXyPfooMzQNQ=cg@mail.gmail.com> <CAO249yfD6na651CSWkzjYRFaEAft9MNyUgjf+X4JNHYJbTCvJw@mail.gmail.com>
From: Yuchung Cheng <ycheng@google.com>
Date: Mon, 25 Jun 2018 13:28:39 -0700
Message-ID: <CAK6E8=cKo98xVdsUSrMK=x4DozdhhwH+78MdYa=MUwiw0hAnjQ@mail.gmail.com>
To: Yoshifumi Nishida <nishida@sfc.wide.ad.jp>
Cc: Neal Cardwell <ncardwell@google.com>, "tcpm@ietf.org" <tcpm@ietf.org>, Eric Dumazet <edumazet@google.com>, Wei Wang <weiwan@google.com>, Van Jacobson <vanj@google.com>
Content-Type: text/plain; charset="UTF-8"
Archived-At: <https://mailarchive.ietf.org/arch/msg/tcpm/QZlFeP3ssCPgQvXUPnoPtbTLP-M>
Subject: Re: [tcpm] Disabling PAWS when possible
X-BeenThere: tcpm@ietf.org
X-Mailman-Version: 2.1.26
Precedence: list
List-Id: TCP Maintenance and Minor Extensions Working Group <tcpm.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tcpm>, <mailto:tcpm-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tcpm/>
List-Post: <mailto:tcpm@ietf.org>
List-Help: <mailto:tcpm-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tcpm>, <mailto:tcpm-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 25 Jun 2018 20:29:23 -0000

> Do you still need TS option even when you have records of transmission time, or this feature is not used in the datacenter?

RACK's packet sent time and TS options are orthogonal. but yes we do
use both. In particular, the TS-opt val in Google DCs is in
microsecond unit, which we negotiated internally using a private
option like what Neal proposed. We do have to relax the PAWs check for
that, so your proposal would make this feature standardize-able for
public Internet :-)

RACK's packet sent time is essential to RACK. But TS-opt is a nice to
have feature to measure RTT on retransmitted packets.

v2.23.0 | Report a Bug | By Email