Re: [trill] Shepherd's report on draft-ietf-trill-ecn-support-04

Donald Eastlake <d3e3e3@gmail.com> Mon, 05 February 2018 04:59 UTC

Return-Path: <d3e3e3@gmail.com>
X-Original-To: trill@ietfa.amsl.com
Delivered-To: trill@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 5D656126CD6 for <trill@ietfa.amsl.com>; Sun, 4 Feb 2018 20:59:34 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.75
X-Spam-Level:
X-Spam-Status: No, score=-1.75 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=no 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 m9eIvp4ccImH for <trill@ietfa.amsl.com>; Sun, 4 Feb 2018 20:59:32 -0800 (PST)
Received: from mail-ot0-x234.google.com (mail-ot0-x234.google.com [IPv6:2607:f8b0:4003:c0f::234]) (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 73E131205D3 for <trill@ietf.org>; Sun, 4 Feb 2018 20:59:32 -0800 (PST)
Received: by mail-ot0-x234.google.com with SMTP id f18so1743768otf.6 for <trill@ietf.org>; Sun, 04 Feb 2018 20:59:32 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=ePQ8b+IcjFzz7OBGjRFb6Bj5cmSJHxOd0TJRfEcG1CE=; b=dU3o5G/MLuiMti48OH9Im5VRNbGHnT1iwXh1DKE1+8tx+XSMxkAep3/jx4Y4fQCMxK 688zK1o35bEuF3K0N1+Dqw9Ttv8tiXKnF9wzelLR/6fNjY4wANL4+RedLCTaGhngpoCw Yw+Iro8Z4e4UFawyS+sfC3mChlrcJ2GTN7eFOv2ggCOWhvhlNfaJpp7jrJDdpjlgVU5W uHwzQ+fI12JKPjYp41GYJfV/owbeHQgGzhGlvUiUEocj3NA57MIhnL1mdaPD17S6xrdt IPEZq5U2kk0WOIXsahL/2eDTeNzf65C98ravzVwlbFLT8CfHyva4ZpsjLicL+xdkcbjz xzgA==
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:content-transfer-encoding; bh=ePQ8b+IcjFzz7OBGjRFb6Bj5cmSJHxOd0TJRfEcG1CE=; b=VrxKZOtaE18ehA5m5WroAJiDG0jzGvrj7uoGXVaZLGFGUZgvx8aFQB7bTqU61ZDAIo lakUrEDSY+2idYA3jURYIQHMVFffMFTt8xyMmrtoI8mxA8XM1a5kc2qFFqNrpk9L6X4B hSMDClT7OffHhxeg71OSTKmoUnXQqrLwb3mSyj1xri+OwoVYTRWaVhV52cWJ1TSKPbfJ lQRKQpszHSN73FllnXFHnM5IyAm4oqBF/C8jYtuBC8CUbC04xnoo4hrlEsAEn3oI+45u s6ZCcWz7ExCQzy0wqXv75AEN9gcaFZ9I1LTmx+ZgXYJEil5PV8hMprsmo8E6Xi6MmviU mdCg==
X-Gm-Message-State: AKwxytfu7GYk21NQPnAwngM2pYP6ht4YA3YJS6vYMiIgJrcOI66mZq+3 yrpPMS1AQ5U/FJT0LXgBrhR94JiE2PibWoPSTCs=
X-Google-Smtp-Source: AH8x227W34AX9e3oPOxu367GdJzwtM3ROn9UpRjlONU0aeNE0oucuN0yrO6gaD54vGi0kd/oSXWMwex9R61adB+1Ktg=
X-Received: by 10.157.19.46 with SMTP id f43mr35065565ote.139.1517806771478; Sun, 04 Feb 2018 20:59:31 -0800 (PST)
MIME-Version: 1.0
Received: by 10.168.67.205 with HTTP; Sun, 4 Feb 2018 20:59:16 -0800 (PST)
In-Reply-To: <b7c521f9-8f5a-4dcd-9a0d-f2439495933a@bobbriscoe.net>
References: <00e901d39394$423c0930$c6b41b90$@ndzh.com> <b7c521f9-8f5a-4dcd-9a0d-f2439495933a@bobbriscoe.net>
From: Donald Eastlake <d3e3e3@gmail.com>
Date: Sun, 04 Feb 2018 23:59:16 -0500
Message-ID: <CAF4+nEH=zKg-cA9eDDR2NW=v6L9gS+ogWH5rQXVpj8eO2Hzxxg@mail.gmail.com>
To: Bob Briscoe <ietf@bobbriscoe.net>
Cc: Susan Hares <shares@ndzh.com>, trill@ietf.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: <https://mailarchive.ietf.org/arch/msg/trill/aQ63PmJdunq50iKhsY6ykgnD6z4>
Subject: Re: [trill] Shepherd's report on draft-ietf-trill-ecn-support-04
X-BeenThere: trill@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: "Developing a hybrid router/bridge." <trill.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/trill>, <mailto:trill-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/trill/>
List-Post: <mailto:trill@ietf.org>
List-Help: <mailto:trill-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/trill>, <mailto:trill-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 05 Feb 2018 04:59:34 -0000

Hi Bob,

All your changes look good to me.

Thanks,
Donald
===============================
 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
 155 Beaver Street, Milford, MA 01757 USA
 d3e3e3@gmail.com


On Sat, Feb 3, 2018 at 8:31 PM, Bob Briscoe <ietf@bobbriscoe.net> wrote:
> Sue,
>
> Thanks for the editorial suggestions.
> Donald, I'm happy with Sue's specific suggestions if you are.
>
> Responses inline...
>
> On 22/01/18 15:18, Susan Hares wrote:
>
> As part of the shepherd’s duties, I’ve review
> draft-ietf-trill-ecn-support-04.txt to determine if it is ready for
> publication.
>
>
>
> Status: Ready with editorial nits
>
>
>
> General comment:  I’m thrilled to see an RBridge specification enacting aids
> for advanced congestion control mechanisms.
>
> What I’ve checked: normative references including
> draft-ietf-twvwg-enc-encap-guidelines-01/txt
>
> BTW, it's currently -09, not -01.
>
> I suggest the following changes to each occurrence of a citation of
> [ECNencapGuide]:
>
> 1. Introduction
> <No change to both citations, which are to the whole of [ECNencapGuide] in
> general>
>
> 3. ECN Support
>
> CURRENT:
>
>    ... which correspond to the recommended provisions of
>    [ECNencapGuide].
>
>
> SUGGESTED:
>
>    ... which correspond to the recommended provisions in section 3 and
> sections 5.1-5.4 of
>    [ECNencapGuide].
>
>
> 3.1. Ingress ECN Support
>
> CURRENT:
>
>       ... it MUST follow the guidelines in [ECNencapGuide]
>       to add a Flags Word to the TRILL Header.
>
>
> SUGGESTED:
>
>       ... it MUST follow the guidelines in Section 5.3 of [ECNencapGuide]
>       to add a Flags Word to the TRILL Header.
>
>
> 3.3 Egress ECN Support
>
> CURRENT:
>
>    Drop is the intended behavior for such a packet, as required by
>    [ECNencapGuide].
>
>
> SUGGESTED:
>
>    Drop is the intended behavior for such a packet, as required by Section
> 5.4 of
>    [ECNencapGuide].
>
>
> CURRENT:
>
>    o  When decapsulating a non-IP protocol frame with a means of
>       indicating ECN that is understood by the RBridge, it MUST follow
>       the guideines in [ECNencapGuide] when setting the ECN information
>       in the decapsulated native frame.
>
>
> SUGGESTED:
>
>    o  When decapsulating a non-IP protocol frame with a means of
>       indicating ECN that is understood by the RBridge, it MUST follow
>       the guideines in Section 5.4 of [ECNencapGuide] when setting the ECN
> information
>       in the decapsulated native frame.
>
>
>
>
>
> Editorial nits are below.  You can adopt or ignore the editorial nits.
>
>
>
> Sue Hares
>
> ===========
>
>
>
> Editorial nits:
>
>
>
> General – it may be helpful to specify section in the [ECNencapGuide] –
> document, and RFC7567.  While the way you specify it is correct, it may help
> the reader to narrow down the scope within the document.
>
>
>
> #1
>
>    Explicit congestion notification (ECN [RFC3168]) allows a forwarding
>
>    element, such as a router, to notify downstream devices, including
>
>    the destination, of the onset of congestion without having to drop
>
>    packets.
>
>
>
> The multiple commons in this sentence do not lend to easy reading of the
> initial sentence.
>
> One alternative is:
>
>
>
>    Explicit congestion notification (ECN [RFC3168]) allows a forwarding
>
>    Element (such as a router) to notify downstream devices, including
>
>    the destination, of the onset of congestion without having to drop
>
>    packets.
>
>
>
> However you may wish to revise the sentence in an alternative way.
>
>
>
>
>
> #2 – Section 2. Paragraph 2. Sentences 4
>
> Old/Extesnion Flags Word./
>
> New/Extension Flags Word./
>
>
>
>
>
> #3 – Section 3.3 is dense and thoughtful text.  I am not sure you can
> improve it, but it too me several reads to make sure I understood it
> correctly.
>
>
>
> I think it might help if we created two subsections within 3.3 for:
> 3.3.1: "Non-ECN Egress RBridge" the first para
> 3.3.2: "ECN Egress RBridge" for the rest of the section
>
> Also, it might make it clearer if the two bullets were explicitly flagged as
> mutually exclusive alternatives:
>
> CURRENT:
>
>    If an RBridge supports ECN, the egress behavior is as follows:
>
> SUGGESTED:
>
>    If an RBridge supports ECN, for the two cases of an IP and a non-IP inner
> packet,
>    the egress behavior is as follows:
>
>
> Then, instead of the two bullet symbols, perhaps use hanging indented
> headers:
>
>    Decapsulating an inner IP packet: The RBridge sets the ECN
>       ...
>    Decapsulating a non-IP protocol frame: If the frame has a means of
>       indicating ECN that is understood by the RBridge, the RBridge MUST
> follow
>       ...
>
>
>
> Other suggested edits to make the going easier:
>
> CURRENT:
>
>          In the case where the TRILL 3-bit ECN codepoint indicates
>       congestion experienced (CE) but the encapsulated native IP frame
>       indicates a not ECN-capable transport (Not-ECT), the RBridge MUST
>       drop the packet.
>
>
> SUGGESTED:
>
>          In the case where the TRILL 3-bit ECN codepoint indicates
>       congestion experienced (CE) but the encapsulated native IP frame
>       indicates a not ECN-capable transport (Not-ECT), it can be seen that
> the RBridge MUST
>       drop the packet.
>
> RATIONALE:
> To reassure the reader that this req't is already described in the table; it
> is not an additional req't.
>
> HTH
>
>
>
> Bob
>
>
>
>
>
>
>
> --
> ________________________________________________________________
> Bob Briscoe                               http://bobbriscoe.net/