Re: [6lo] Martin Duke's Discuss on draft-ietf-6lo-blemesh-09: (with DISCUSS)

Martin Duke <martin.h.duke@gmail.com> Thu, 22 April 2021 18:36 UTC

Return-Path: <martin.h.duke@gmail.com>
X-Original-To: 6lo@ietfa.amsl.com
Delivered-To: 6lo@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 4F9143A13C4; Thu, 22 Apr 2021 11:36:44 -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, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=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 n7sdv-gfbfDy; Thu, 22 Apr 2021 11:36:39 -0700 (PDT)
Received: from mail-io1-xd2d.google.com (mail-io1-xd2d.google.com [IPv6:2607:f8b0:4864:20::d2d]) (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 D10AA3A13D4; Thu, 22 Apr 2021 11:36:32 -0700 (PDT)
Received: by mail-io1-xd2d.google.com with SMTP id g125so17853877iof.3; Thu, 22 Apr 2021 11:36:32 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=LoX2Ac6YJ4EU17y1TAg+7fx0SZoN9KMLdhb3P1OqeB8=; b=cgIWqeMRKfGbf3b5NWYgdEJWmtdvfO/5AvXK3UTWkOmHy6BAUML/1zT3WTLsxTeTkl gZ9BeDd0GN66TuXhYoNBgbaW4ntXrx1Bj01IIlAPpVbxRd5m2pUA3dC1D6LbROdnjR8+ AcELW03vOLI7W3EFszsaKu0RMMt5t2oxUgb7h+ZEZzdGbGIkVo8WNpJQRRP1GrmBf/BP Di/8CEEyE+t1jQ6L5KpSbfPlmF9rxPxUL+TNueWPzUm1VPczOCMAAk0i4OqXFJf1+Jwk nHGjYOWjx+3zvRzJ4suhrk4Bfl1LlUU0sMiBGE6CCIj813OV1EuSFutKPxFoDpZ/aJXD rDAw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=LoX2Ac6YJ4EU17y1TAg+7fx0SZoN9KMLdhb3P1OqeB8=; b=hs7K537xfwZ1xtHe+wNaocYowX9LWeuK5letO9kP/bJ2PUdixE7/WvcWWEuh/joe1S r5pWBGW6v6FihMahoIsRYeXK9jDAzgDS35QdK4QmdAP1CHYE/It1zyPeXFe7a6JYM2t8 c+LUQ05hDxqN2FCZpsUa4f0cpG/G8b60JGyFY6GBJp3vU3nFh7uFUdMEexOhgKszKnhb d3G0zZQYz84EUmLr8+LsmxhDLTE8/e1cv14x8uLM4vqv6k9JjYMWwhOn5p2T3W9HACYq f7zTIVj0ae2cd9QA8ul/iyFo76MXm9RFHHZlSg4C9nR3yXdqgQrTrq6lRVE/sG+Amp7P Mshw==
X-Gm-Message-State: AOAM5310Uyyo5IMXz8R+L4p6WOcxRzSnnSqcMx7ax7SyaeeZWU5PTC2Z feXXmtX94T8sE8ScrNIeSbzCS2RJV1M43p1Nk8kn9KW9XH8=
X-Google-Smtp-Source: ABdhPJzqglNTHdqMWnbQUJhOqkHLz5BUiMaHQqNLR4RJwPWXHkEi521VL7H1wCItNCWmzHzb76ahb7U7surSCSwCUcI=
X-Received: by 2002:a05:6638:bcb:: with SMTP id g11mr200415jad.144.1619116589934; Thu, 22 Apr 2021 11:36:29 -0700 (PDT)
MIME-Version: 1.0
References: <161412454173.21320.1024712833153341251@ietfa.amsl.com> <36b643541d8b15edd666c55f3ee14f3f.squirrel@wmail.entel.upc.edu>
In-Reply-To: <36b643541d8b15edd666c55f3ee14f3f.squirrel@wmail.entel.upc.edu>
From: Martin Duke <martin.h.duke@gmail.com>
Date: Thu, 22 Apr 2021 11:36:23 -0700
Message-ID: <CAM4esxTg3FgH5Y8fD+DiJbSJQJMo1Y0BFn9gc_wjC5A-YcOdiQ@mail.gmail.com>
To: Carles Gomez Montenegro <carlesgo@entel.upc.edu>
Cc: The IESG <iesg@ietf.org>, rahul.ietf@gmail.com, 6lo-chairs@ietf.org, draft-ietf-6lo-blemesh@ietf.org, 6lo@ietf.org
Content-Type: multipart/alternative; boundary="000000000000316a8205c093f592"
Archived-At: <https://mailarchive.ietf.org/arch/msg/6lo/uEuQd6Z6hdJ3B8YM0F1qS7H-BdM>
Subject: Re: [6lo] Martin Duke's Discuss on draft-ietf-6lo-blemesh-09: (with DISCUSS)
X-BeenThere: 6lo@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Mailing list for the 6lo WG for Internet Area issues in IPv6 over constrained node networks." <6lo.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/6lo>, <mailto:6lo-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/6lo/>
List-Post: <mailto:6lo@ietf.org>
List-Help: <mailto:6lo-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/6lo>, <mailto:6lo-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 22 Apr 2021 18:36:45 -0000

I didn't mean to suggest that you can't support higher MTUs, but the latest
version definitely addresses my DISCUSS. Thanks.

On Thu, Apr 22, 2021 at 3:13 AM Carles Gomez Montenegro <
carlesgo@entel.upc.edu> wrote:

> Hi Martin,
>
> Thank you very much for your feedback, and apologies for the late response.
>
> We just published an updated version of the draft (revision -10).
>
> Regarding your Discuss point, after discussion among the authors and with
> the WG, we aim to address the issue by stating now that:
>
>   “As per the present specification, the MTU size for IPv6 mesh over BLE
>    links is 1280 octets.”
>
> (Initially we thought that it might be a good idea to keep the flexibility
> offered by the IPSP in this regard, but we finally realized that it was
> not such a good idea.)
>
> Should you have further comments, please let us know.
>
> Thanks,
>
> Carles (on behalf of all the authors)
>
>
>
> > Martin Duke has entered the following ballot position for
> > draft-ietf-6lo-blemesh-09: Discuss
> >
> > When responding, please keep the subject line intact and reply to all
> > email addresses included in the To and CC lines. (Feel free to cut this
> > introductory paragraph, however.)
> >
> >
> > Please refer to
> https://www.ietf.org/iesg/statement/discuss-criteria.html
> > for more information about IESG DISCUSS and COMMENT positions.
> >
> >
> > The document, along with other ballot positions, can be found here:
> > https://datatracker.ietf.org/doc/draft-ietf-6lo-blemesh/
> >
> >
> >
> > ----------------------------------------------------------------------
> > DISCUSS:
> > ----------------------------------------------------------------------
> >
> > I found this paragraph in Section 3.1 to be hand-wavy:
> >
> > "Note that this specification allows using different MTUs in different
> >    links.  If an implementation requires use of the same MTU on every
> >    one of its links, and a new node with a smaller MTU is added to the
> >    network, a renegotiation of one or more links can occur.  In the
> >    worst case, the renegotiations could cascade network-wide.  In that
> >    case, implementers need to assess the impact of such phenomenon."
> >
> > What are the consequences of link "renegotiation"? If every MTU downgrade
> > results in a storm of messages, that's a bad property. Is the use case
> > where
> > the MTU must be the same on all links an important one? If not, simply
> > requiring hosts to handle this case seems way cleaner.
>
>
>