Re: [mpls] Alvaro Retana's Discuss on draft-ietf-mpls-rsvp-shared-labels-07: (with DISCUSS and COMMENT)
Alvaro Retana <aretana.ietf@gmail.com> Wed, 23 January 2019 21:53 UTC
Return-Path: <aretana.ietf@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 D2BC0130F33; Wed, 23 Jan 2019 13:53:01 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.998
X-Spam-Level:
X-Spam-Status: No, score=-0.998 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, FREEMAIL_REPLY=1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, UNPARSEABLE_RELAY=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 DZxNf-noRvUy; Wed, 23 Jan 2019 13:52:59 -0800 (PST)
Received: from mail-ot1-x334.google.com (mail-ot1-x334.google.com [IPv6:2607:f8b0:4864:20::334]) (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 7D59D130F30; Wed, 23 Jan 2019 13:52:59 -0800 (PST)
Received: by mail-ot1-x334.google.com with SMTP id e12so3388642otl.5; Wed, 23 Jan 2019 13:52:59 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:in-reply-to:references:mime-version:date:message-id:subject:to :cc; bh=/P1uyAWRTPjGyRNcZlaT6RNEphVuk/YNZdrc/GIRwWE=; b=Ic5TestWe+FofN1hQnz5ZZVMT1doJWN6OknbvQi4jP8EYFygYvL6ZS84HVM2ZymKtU uF6ZQ3xrtBQMXiDvEkdoqKeA2no+VuOa5RH+YA1TFPzds5yEGPttNEh3J2MvHwlO+3jC mimHSjxa+YhHP8vXN9YXPLY1Nf8cV/OzeLW8JPZAMI9fXq846kL4IeMx9EwNJAgyff04 s82LGP6OachX4q5J6ov+F4xeh+4lkIY/V2jVLpSVmW28b6rU3fojCCkTHKyhxoEMBfqp 8m42LZjRLJpgpp8mrPvyAMaBreCjVukFMshmEU5orMA5LlB09Ylc+Ret5dIqprxXmhUK idlA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:in-reply-to:references:mime-version:date :message-id:subject:to:cc; bh=/P1uyAWRTPjGyRNcZlaT6RNEphVuk/YNZdrc/GIRwWE=; b=orApXmexSSapgC5udQuHMi6LKSempmpqKp4uxR0uylWcNTocDXZpWixg7KQ2Ln/Ivi rQmIzcgKNEDhp2j1YbiZVxoNR+KwuiRjdu4JQ75d+bKoQPX5Ls9mfpE6Fvtz0ubgvQTm NDijEM4EmbYc47ItgD8E8H/9iiG+kJxjcMKDxqV+6wBkJF3iy4+RKtVmSiRwaBzrSnPq 6wkVZfQ6Uk2obEXzXTDUcf5ACXBX/tlGwfQegTDUsguv8/NdJPtF27QJdNxMONMV0b6E 9j9Uh9L3GTd/LU51Lo0FvhYZ/NlhaJJUmdKUUEVqUvbXowj17AZMdkuZBe/enrM3NvqJ GIMQ==
X-Gm-Message-State: AJcUukdvWTxMSTFCyBD1ib7g3Ws+MWgwiM2YC0O8Lwzt/nsEak3WDR+h 6nx1L+kkk+4OEwku/vKpTA7OPcnfWCASi0RKFGs=
X-Google-Smtp-Source: ALg8bN6xAmJlzyQZdA777n6DQOnHQno1ZWqe8JEFd/ncpdH+Syga37E2JdTUUY08TQI3WAYf5u/fqsdH0eFDpjP4IZ4=
X-Received: by 2002:a9d:694a:: with SMTP id p10mr2780629oto.44.1548280378728; Wed, 23 Jan 2019 13:52:58 -0800 (PST)
Received: from 1058052472880 named unknown by gmailapi.google.com with HTTPREST; Wed, 23 Jan 2019 13:52:58 -0800
From: Alvaro Retana <aretana.ietf@gmail.com>
In-Reply-To: <CA+YzgTtbKfWdc9b_+jasOOegGs+PUL3v6CXO=fO95AQophdJaQ@mail.gmail.com>
References: <154508592591.4271.12094992121838897393.idtracker@ietfa.amsl.com> <CA+YzgTtfVDObu90XrVporj9UU_RYfK1Qs=P5XfUzn-NXLPOckg@mail.gmail.com> <CAMMESsyjOGXkfx9VzepDTwWdVNqDwyNMmG==S9vf4r3mUBz+Tg@mail.gmail.com> <CA+YzgTu3Q69-V-M0d8XtnCa7xsRYjdPCiSgvOXKpOshyeOCGQg@mail.gmail.com> <CA+YzgTtbKfWdc9b_+jasOOegGs+PUL3v6CXO=fO95AQophdJaQ@mail.gmail.com>
MIME-Version: 1.0
Date: Wed, 23 Jan 2019 13:52:58 -0800
Message-ID: <CAMMESsyKaerwgfxAWtXvhRF3guUituMFh280ZbHU1npd6W04xw@mail.gmail.com>
To: Vishnu Pavan Beeram <vishnupavan@gmail.com>
Cc: mpls-chairs@ietf.org, IETF MPLS List <mpls@ietf.org>, draft-ietf-mpls-rsvp-shared-labels@ietf.org, The IESG <iesg@ietf.org>
Content-Type: multipart/alternative; boundary="000000000000fcabb50580271d8a"
Archived-At: <https://mailarchive.ietf.org/arch/msg/mpls/6ef7R0a9_vITp62FTrLGRJviUJ8>
Subject: Re: [mpls] Alvaro Retana's Discuss on draft-ietf-mpls-rsvp-shared-labels-07: (with DISCUSS and COMMENT)
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, 23 Jan 2019 21:53:02 -0000
On January 18, 2019 at 8:43:42 AM, Vishnu Pavan Beeram ( vishnupavan@gmail.com) wrote: Pavan: Hi! We just uploaded a new rev (-08) for this draft. Please do go through the diffs ( https://www.ietf.org/rfcdiff?url2=draft-ietf-mpls-rsvp-shared-labels-08) and let us know if all your comments have been addressed. No, not completely. See below. ... >> ---------------------------------------------------------------------- >>> DISCUSS: >>> ---------------------------------------------------------------------- >>> >>> A significant portion of this specification depends on knowing the label >>> stack >>> depth limits in the network, but §5.2 declares the mechanism out of >>> scope: >>> >>> In order to accurately pick >>> the delegation hops, the ingress needs to be aware of the label stack >>> depth push limit of each of the transit LSRs prior to initiating the >>> signaling sequence. The mechanism by which the ingress or controller >>> (hosting the path computation element) learns this information is >>> outside the scope of this document. >>> >>> I think that not defining the mechanism in this document is ok -- but not >>> having one means that important parts of this specification can't work. >>> Please >>> point at where such a mechanism is specified, or at least provide >>> examples. >>> >>> The Shepherd's writeup says that "implementation plans and >>> implementations" are >>> known so I think that this should be an easy point to address. >>> >>> >>> >> [VPB] The specification discusses a couple of delegation options -- the >> explicit delegation option (Section 5.2) and the automatic delegation >> option (Section 5.3). The explicit delegation option is the only one that >> needs the ingress or the controller to be aware of the label stack depth >> push limit of each of the transit LSRs prior to signaling. This information >> is not needed when the automatic delegation option is employed -- the >> limitations of each transit node are taken into account while picking the >> delegation hops during the initial signaling sequence. >> >> >> >> For the explicit delegation option, an implementation may choose to >> employ any of the following mechanisms to learn the label stack depth push >> limit of each LSR in the network -- ISIS (RFC8491), OSPF (RFC8476), >> BGP-LS (draft-ietf-idr-bgp-ls-segment-routing-msd), PCEP >> (draft-ietf-pce-segment-routing), local config (just set a global limit), >> netconf/restconf/grpc using the data-model specified in >> draft-ietf-teas-yang-sr-te-topo. >> >> >> >> Please see if the addition of the following statement to the end of the >> first paragraph in Section 5.2 addresses your concern: >> >> >> >> "Examples of such a mechanism are specified in RFC8491 and RFC8476." >> >> These are fine examples, and they would satisfy the point above. >> >> However, they raise an additional one. rfc8491 has a very specific >> definition of what the Base MPLS Imposition MSD is, but that definition may >> not match what is discussed here. The intent may be the same, but the text >> is different, and given the extensive discussion prior to the publication >> of rfc8491, I want to make sure that we are in fact talking about the same >> thing: "label stack depth push limit” doesn’t directly map to "the total >> number of MPLS labels that can be imposed, including all >> service/transport/special labels” [rfc8491]. I note that this document >> specifically mentions just transport labels. >> >> If the definition of the BMI-MSD is what is expected in this document, >> please explicitly say so. If not, then I think that we would need to >> define a new MSD-Type for the suggestions above to be applicable. >> > [Pavan] The “label stack depth push limit” is the same as what is referred > to as the BMI-MSD in RFC8491. We will make that explicit. > I see no place in the text where the relationship to the BMI-MSD is explicitly made. I see the text (in parenthesis) that you added in §5.3: "label stack depth push limit (number of MPLS labels that can be imposed)”, but that doesn’t make reference to either the BMI-MSD or rfc8491. Also, the text added is not the complete definition. All this would make rfc8491 a Normative reference. Thanks! Alvaro.
- [mpls] Alvaro Retana's Discuss on draft-ietf-mpls… Alvaro Retana
- Re: [mpls] Alvaro Retana's Discuss on draft-ietf-… Vishnu Pavan Beeram
- Re: [mpls] Alvaro Retana's Discuss on draft-ietf-… Alvaro Retana
- Re: [mpls] Alvaro Retana's Discuss on draft-ietf-… Vishnu Pavan Beeram
- Re: [mpls] Alvaro Retana's Discuss on draft-ietf-… Vishnu Pavan Beeram
- Re: [mpls] Alvaro Retana's Discuss on draft-ietf-… Alvaro Retana
- Re: [mpls] Alvaro Retana's Discuss on draft-ietf-… Vishnu Pavan Beeram
- Re: [mpls] Alvaro Retana's Discuss on draft-ietf-… Alvaro Retana
- Re: [mpls] Alvaro Retana's Discuss on draft-ietf-… Vishnu Pavan Beeram
- Re: [mpls] Alvaro Retana's Discuss on draft-ietf-… Alvaro Retana