[Ice] RFC8445 triggered checks cancelation clarification

Sergey Ilinykh <rion4ik@gmail.com> Tue, 28 April 2020 11:20 UTC

Return-Path: <rion4ik@gmail.com>
X-Original-To: ice@ietfa.amsl.com
Delivered-To: ice@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C065A3A1379 for <ice@ietfa.amsl.com>; Tue, 28 Apr 2020 04:20:52 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.098
X-Spam-Level:
X-Spam-Status: No, score=-2.098 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, 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 Fe2yKM05l286 for <ice@ietfa.amsl.com>; Tue, 28 Apr 2020 04:20:51 -0700 (PDT)
Received: from mail-ua1-x929.google.com (mail-ua1-x929.google.com [IPv6:2607:f8b0:4864:20::929]) (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 79D463A1377 for <ice@ietf.org>; Tue, 28 Apr 2020 04:20:51 -0700 (PDT)
Received: by mail-ua1-x929.google.com with SMTP id u12so20850367uau.10 for <ice@ietf.org>; Tue, 28 Apr 2020 04:20:51 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=/1V6Uu1chYomNb8hS3B4n2QjvxqAsLLnlFzuYsUdl6w=; b=hCeDbVcLSlAvudeFaNgNWSOa0jM+7fJt3cDcIkw0gKuy+ptaY6WMBi/KiWLeuwZRe4 ygLbv6kCDujuC9V/VLRvvxl1AHGZo4jVxzGeaIsu77uejKOBrpTDzGa1a7IZyFWxutL4 A8TgIncqIbT98nL2YbC17yG8yZS6SOgC6+sCNbXcD8UBh4lIY1X+8sTiV2bnNRtUTwCS RJqF3sEcKtc5WUVOQvUufhbWU3/a6SPt2gSAwNol+xacXlYyoHuHdVgor4MwtqvjWYjN pXrJuZC0UWr6PDaxpzWYMYvgYulSjuLWaLaOZ6sCjcfn6bJGRsjpHFux90Er4CDKwVfk 7kNw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=/1V6Uu1chYomNb8hS3B4n2QjvxqAsLLnlFzuYsUdl6w=; b=AfmZDl3ws03gm7+REGAV3Px/I2l6Oslei28mP8tGf73tsn7oZQc5e6Js0O5cqQsTnA t4N+RRpf11hut41PJ3qgb4q8fDBOuV7zLd5eQwdXkSxjHgpf44NNkqu/QTnMT4H2V393 se06SlRYdCc1APOZWuwUg7Kdg9tQjRffU4xTwpRSWX/Ihf9+JQ2vWvV5ta/1bgbHgq+r gymcC6ZNS8sD+tGLvmC6yiQimtgqc2NA6py/H84U1jYXI8jbVWxWIjoTk1AjlLl+saLs gKjLC3vi2+BD62bALgWbjRE/rVgEurtMk4trHuhOHn8Q9PowRc2vB1zzXETc8iqcE8zA Z7Lg==
X-Gm-Message-State: AGi0PuZ+Hv/mezB4hkVL/HAViSJEV/516/GJ3S6er/0sdzenyMwWl5dT 5s2nas06R/vYIxJ3x3p1sSs83dTUmXKWFaFuoHUZCCQx
X-Google-Smtp-Source: APiQypKUkV51QpujvuVz/J+mlhLd+xpjcThdU2Th47BrzC4rtNBrhgsSwgsfcIXTk4uN6e0BH+znvWwc3/AurpD0NdQ=
X-Received: by 2002:ab0:6893:: with SMTP id t19mr8566020uar.37.1588072850255; Tue, 28 Apr 2020 04:20:50 -0700 (PDT)
MIME-Version: 1.0
From: Sergey Ilinykh <rion4ik@gmail.com>
Date: Tue, 28 Apr 2020 14:20:56 +0300
Message-ID: <CALV4eUXJj1DJ+nGJF48PnBi6MtLHaQRFM1BTe_-sFWty2N-LsA@mail.gmail.com>
To: ice@ietf.org
Content-Type: multipart/alternative; boundary="0000000000001df83a05a45806f4"
Archived-At: <https://mailarchive.ietf.org/arch/msg/ice/L1MH2vwWOk9VBu6FUrOSR_319tY>
X-Mailman-Approved-At: Wed, 29 Apr 2020 08:03:17 -0700
Subject: [Ice] RFC8445 triggered checks cancelation clarification
X-BeenThere: ice@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Interactive Connectivity Establishment \(ICE\)" <ice.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ice>, <mailto:ice-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ice/>
List-Post: <mailto:ice@ietf.org>
List-Help: <mailto:ice-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ice>, <mailto:ice-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 28 Apr 2020 11:29:30 -0000

Hi.

There a couple of points to clarify about triggered checks.

1. Since a triggered check can cancel current in-progress transaction it
may cause a long loop of cancels and rechecks on both sides.

It's a somewhat rare situation but still possible when both sides send
triggered checks to each other simulatentously.
To avoid this I think triggered checks should not be cancelled by other
triggered checks on the same pair.

2. The document states Cancel should wait for a response but avoid handling
errors as well as don't do any retransmissions.

>From the document it's not clear where a success binding request from a
cancelled transaction has to be handled as usually or not.
If yes it also remedies 1 quite a bit.


Best Regards,
Sergey