Re: [mpls] MPLS-RT review of draft-mirsky-mpls-p2mp-bfd-04

"Andrew G. Malis" <agmalis@gmail.com> Wed, 31 October 2018 13:41 UTC

Return-Path: <agmalis@gmail.com>
X-Original-To: mpls@ietfa.amsl.com
Delivered-To: mpls@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 857DF127598; Wed, 31 Oct 2018 06:41:04 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.999
X-Spam-Level:
X-Spam-Status: No, score=-1.999 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, 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 oB9vTj2CGijO; Wed, 31 Oct 2018 06:41:02 -0700 (PDT)
Received: from mail-qk1-x741.google.com (mail-qk1-x741.google.com [IPv6:2607:f8b0:4864:20::741]) (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 E8376124BAA; Wed, 31 Oct 2018 06:41:01 -0700 (PDT)
Received: by mail-qk1-x741.google.com with SMTP id e4so9481192qkh.6; Wed, 31 Oct 2018 06:41:01 -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=iV5eKkvgHNAsqbk7QJuBSW5bmhtmfHG/P5hHwWoucIA=; b=HrkjVsamMgMTtuXlgbhztCHR6/J1fxHVNkRVxMyk3veYa5Oc92+l3pIp3ISiQU8xrv wuEkubCXJ8VlCR3CcJ52qJZ4Opbn9MFKlB54A1w8Pskt4Iy7YkUIhJ2fvL+CXLcPrQe5 5uFY8v7E5DmK9pp/dq7nRovjP7OvtFbWVEHpbDfJTePVUp+Y1/zgluyqnVcnjbVvy/c+ dnakZW44P3RsjRRsF1P9w9eTDmAJyNf8LcA2EI/Tauh3AqV2Gs1unBYHWFyHgg8ik0cj qOUEtF83+oaoEnddilos8/9liJXfF/xqmtUysaRtCusS4c8YPUlHUx0GjwWk6h+bsbrX sSig==
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=iV5eKkvgHNAsqbk7QJuBSW5bmhtmfHG/P5hHwWoucIA=; b=asCiW7Z3V4+sPXhfUGrqCMq9QasOdfxZ6Z10GysmZLG/Om+PDjHNqU/TbttZLTQ2ZO muOwkKJxWEF33uqT0ZIINEyHAOvQR0justNUFKhnQ1F+Kc4/L6wy2Hisb6ghqJfOSR5F esgapOBTV7z6v7bQqpSAWbUuo1EC+6nc4YtpsfjDGR9jpLVYPxMcQirdCSshkXz5NNar DUsLraViFaarAjiWkLTOFDL7azbtEv7MoOnc0Bk1P4g8Gh+3QSe+Q7f0dJfEpLIakfLJ COwrp6KYnftdE7pmEa3wwIjwu+iOSVJJyWE8jl6xS/xCGQ0yP9C1Kzmexu4gIzztxSG+ WafA==
X-Gm-Message-State: AGRZ1gJTHQf5UJ0aItVOkOlFnsoX8zmesIdw4Kb+Y8FfalkHlNpqzjlI S7FfATKgfWKd6CmDwlYMvJ7Pu1HL9n8ZySs9BkU=
X-Google-Smtp-Source: AJdET5fWytHXfEBlXIi7PZCw9ExGAxIAb3n/IHWsVC3110vYkQNW++4ppUy9h8sqob8e/bPg1dMUuWt7E3IPPEBh10U=
X-Received: by 2002:a37:99c5:: with SMTP id b188mr1074172qke.100.1540993260878; Wed, 31 Oct 2018 06:41:00 -0700 (PDT)
MIME-Version: 1.0
References: <CAA=duU2kQWCg5CfidXAw8M+1VivgY=C2cehCcEVUQ0D_1yYxSg@mail.gmail.com> <CA+RyBmVLDKOsaJhDzdDKmF9WEk1Hwg7-LN25onVdK3fXk7bHSw@mail.gmail.com> <CA+RyBmXeQp+jFji-s5SsMDZTiwgNZ2Zfkcc0NHhwvnQ7jegdow@mail.gmail.com>
In-Reply-To: <CA+RyBmXeQp+jFji-s5SsMDZTiwgNZ2Zfkcc0NHhwvnQ7jegdow@mail.gmail.com>
From: "Andrew G. Malis" <agmalis@gmail.com>
Date: Wed, 31 Oct 2018 09:40:49 -0400
Message-ID: <CAA=duU3eaXNPhSddxDxzrazL8NSwsVpR2TtkxLqH3YODBf=3Yw@mail.gmail.com>
To: Greg Mirsky <gregimirsky@gmail.com>
Cc: mpls-chairs <mpls-chairs@ietf.org>, draft-mirsky-mpls-p2mp-bfd@ietf.org, mpls@ietf.org
Content-Type: multipart/alternative; boundary="000000000000ea7fdd0579867348"
Archived-At: <https://mailarchive.ietf.org/arch/msg/mpls/tnahmerZ_mYM_GteY15l3Bdm_Hk>
Subject: Re: [mpls] MPLS-RT review of draft-mirsky-mpls-p2mp-bfd-04
X-BeenThere: mpls@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Multi-Protocol Label Switching WG <mpls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/mpls>, <mailto:mpls-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/mpls/>
List-Post: <mailto:mpls@ietf.org>
List-Help: <mailto:mpls-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/mpls>, <mailto:mpls-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 31 Oct 2018 13:41:05 -0000

Greg,

Thanks for checking.

You didn't really address my comment: "I would have expected to see at
least a reference to RFC 4687, "Operations and Management (OAM)
Requirements for Point-to-Multipoint MPLS Networks", and some text on how
this draft addresses the requirements in that draft.".

You added a reference in the security section, but nothing about how your
draft addresses the 4687 requirements.

Also, you didn't really address my next comment: "I also expected more text
on the relationship between this draft and RFC 6425, "Detecting Data-Plane
Failures in Point-to-Multipoint MPLS - Extensions to LSP Ping"', and more
of an explanation of why the keyword MAY is used in sections 4.1 and 4.2 -
what are the implications of following or not following the MAY in each
case?"

Regarding RFC 6425, I was looking for text along the lines of why one would
choose to implement this draft rather than 6425 (or both), to give product
implementers and network operators guidance on whether to use 6425, this
draft, or both for MPLS p2mp data plane failure detection. Otherwise, why
would they bother with this draft when they already have 6425 working?

Also, in sections 4.1 and 4.2, you just added another MAY to section 4.1,
but again, what happens if you don't do the MAYs in both sections? Why
would I want to do the MAYs? Why would I not want to? The text doesn't say.

Finally, in section 3, the following sentence doesn't scan:

   The source IP
   address MAY be drawn from the IP header if BFD control packet
   transmitted by the head using IP/UDP encapsulation as described in
   Section 3.1.

Did you mean "uses" instead of "using"?

Thanks,
Andy





On Tue, Oct 30, 2018 at 11:05 AM Greg Mirsky <gregimirsky@gmail.com> wrote:

> Dear Andy,
> thank you for the review and the detailed suggestions. Attached please
> find the updated version of the draft and the diff to highlight the
> proposed changes. Please let me know if these address your comments.
>
> Kind regards,
> Greg
>
> On Wed, Oct 24, 2018 at 11:11 AM Greg Mirsky <gregimirsky@gmail.com>
> wrote:
>
>> Dear Andy,
>> thank you for your thorough review and the most helpful comments. I'll
>> work on the update to address them.
>>
>> Regards,
>> Greg
>>
>> On Wed, Oct 24, 2018 at 9:17 AM Andrew G. Malis <agmalis@gmail.com>
>> wrote:
>>
>>> I’ve been selected as an MPLS-RT reviewer for
>>> draft-mirsky-mpls-p2mp-bfd-04, which is currently a candidate for MPLS WG
>>> adoption. This draft documents procedures for using BFD for multipoint
>>> networks to detect data plane failures in MPLS p2mp LSPs.
>>>
>>> The BFD WG has been working on draft-ietf-bfd-multipoint, which
>>> describes BFD procedures for multipoint and multicast networks.
>>> draft-mirsky-mpls-p2mp-bfd uses that draft as a basis to detect MPLS data
>>> plane failures for p2mp LSPs. This is a straightforward and useful
>>> application of the BFD draft for MPLS data plane failure detection.
>>>
>>> However, I would have expected to see at least a reference to RFC 4687,
>>> "Operations and Management (OAM) Requirements for Point-to-Multipoint MPLS
>>> Networks", and some text on how this draft addresses the requirements in
>>> that draft.
>>>
>>> I also expected more text on the relationship between this draft and RFC
>>> 6425, "Detecting Data-Plane Failures in Point-to-Multipoint MPLS -
>>> Extensions to LSP Ping"', and more of an explanation of why the keyword MAY
>>> is used in sections 4.1 and 4.2 - what are the implications of following or
>>> not following the MAY in each case?
>>>
>>> The draft also needs an editing pass, for example "MaultipointHead" for
>>> "MultipointHead" and some incorrect English grammar in several places.
>>>
>>> Once these items have been addressed, I think that the draft should be
>>> ready for an adoption call.
>>>
>>> Cheers,
>>> Andy
>>>
>>>
>>>