Re: [mpls] consolidated response to Q12/15 on T-MPLS
"Thomas D. Nadeau" <tnadeau@cisco.com> Mon, 24 April 2006 13:06 UTC
Received: from [127.0.0.1] (helo=stiedprmman1.va.neustar.com) by megatron.ietf.org with esmtp (Exim 4.43) id 1FY0le-0001WB-83; Mon, 24 Apr 2006 09:06:18 -0400
Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1FY0ld-0001W6-LU for mpls@ietf.org; Mon, 24 Apr 2006 09:06:17 -0400
Received: from rtp-iport-1.cisco.com ([64.102.122.148]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1FY0ld-0002gD-65 for mpls@ietf.org; Mon, 24 Apr 2006 09:06:17 -0400
Received: from rtp-core-1.cisco.com ([64.102.124.12]) by rtp-iport-1.cisco.com with ESMTP; 24 Apr 2006 06:06:17 -0700
X-BrightmailFiltered: true
X-Brightmail-Tracker: AAAAAA==
X-IronPort-AV: i="4.04,151,1144047600"; d="scan'208"; a="26534809:sNHT27020832"
Received: from xbh-rtp-201.amer.cisco.com (xbh-rtp-201.cisco.com [64.102.31.12]) by rtp-core-1.cisco.com (8.12.10/8.12.6) with ESMTP id k3OD6GTL020088; Mon, 24 Apr 2006 09:06:16 -0400 (EDT)
Received: from xfe-rtp-201.amer.cisco.com ([64.102.31.38]) by xbh-rtp-201.amer.cisco.com with Microsoft SMTPSVC(6.0.3790.211); Mon, 24 Apr 2006 09:06:16 -0400
Received: from [10.83.15.50] ([10.83.15.50]) by xfe-rtp-201.amer.cisco.com with Microsoft SMTPSVC(6.0.3790.211); Mon, 24 Apr 2006 09:06:15 -0400
In-Reply-To: <4449589E.8020808@pi.se>
References: <4449589E.8020808@pi.se>
Mime-Version: 1.0 (Apple Message framework v749.3)
Content-Type: text/plain; charset="US-ASCII"; delsp="yes"; format="flowed"
Message-Id: <F5A6939B-5A35-4FAB-B30A-744402926635@cisco.com>
Content-Transfer-Encoding: 7bit
From: "Thomas D. Nadeau" <tnadeau@cisco.com>
Subject: Re: [mpls] consolidated response to Q12/15 on T-MPLS
Date: Mon, 24 Apr 2006 09:06:27 -0400
To: Loa Andersson <loa@pi.se>
X-Mailer: Apple Mail (2.749.3)
X-OriginalArrivalTime: 24 Apr 2006 13:06:15.0621 (UTC) FILETIME=[DE737F50:01C6679F]
X-Spam-Score: 0.0 (/)
X-Scan-Signature: a743e34ab8eb08259de9a7307caed594
Cc: mpls@ietf.org
X-BeenThere: mpls@lists.ietf.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Multi-Protocol Label Switching WG <mpls.lists.ietf.org>
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/mpls>, <mailto:mpls-request@lists.ietf.org?subject=unsubscribe>
List-Archive: <http://www1.ietf.org/pipermail/mpls>
List-Post: <mailto:mpls@lists.ietf.org>
List-Help: <mailto:mpls-request@lists.ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/mpls>, <mailto:mpls-request@lists.ietf.org?subject=subscribe>
Errors-To: mpls-bounces@lists.ietf.org
Loa, You see to have missed one of the comments which came from at least 2 of the comments received during the WG meeting and afterwards. In particular, you do not ask that the "T-MPLS" name remove "MPLS" from the name. This probably best falls under the "T-MPLS trademark" subsection below. I suggest you simply change the subheading to "Specification Naming" and add a paragraph explaining the above regarding name change, and also include the trademark discussion. --Tom > Working Group, > > this is the consolidated list of concerns we've sent to the Q12/15. > > Note that we will further refine this list and send our formal > response May 17th. Further comments are welcome. > > Loa and George > > -- > Loa Andersson > > Principal Networking Architect > Acreo AB phone: +46 8 632 77 14 > Isafjordsgatan 22 mobile: +46 739 81 21 64 > Kista, Sweden email: loa.andersson@acreo.se > loa@pi.se > > Areas of concerns on Transport MPLS from the MPLS working group > =============================================================== > > To: Q12/15 > > At this point, members of the IETF are expressing their concerns on > Transport-MPLS on the MPLS and CCAMP mailing lists. We are working > to collect and evaluate these and come to a consensus response to > your liaison. > > The included somewhat consolidated list is still preliminary, e.g. > it still lacks in structure. > > However we would like to alert you that our preliminary judgment is > that some of the issues are of a serious nature. At least PHP, > signaling protocol and reserved labels are of this serious nautre. > > More careful reading of the documents reveals that there is an > appendix in G.8110.1 that addresses MPLS pseudowires. This document > should also have been liaised to the PWE3 working group in the > IETF as well. This appendix references draft-pan-pwe3-over-sub-ip-01 > this draft is no longer active. > > Requirements > ------------ > We have not seen any requirements specification for T-MPLS. > > Penultimate Hop Popping (PHP) > ----------------------------- > We discussed this several times with different ITU-T SGs and > Questions, we've agreed that the right way of stating this is > that it is "mandatory to implement, optional to use" PHP. We > would appreciate if the T-MPLS could adopt the same text. > > Note: We also think that it is a misconception to think that > non-PHP is less complex than PHP. > > Signaling protocol > ------------------ > It is nowhere specified which signaling protocol will be used for > for T-MPLS. > > It is also unclear if traffic engineering functionality is required. > > Note: if traffic engineering functionality is required, there > is a strong recommendation from the IETF to use RSVP-TE. > > Note 2: If this effort leads to requirements on changes in the IETF > signaling protocols this should be handled according to > draft-andersson-rtg-gmpls-change-02. > > Non-merging > ----------- > T-MPLS states that merging of LSPs is not used. > > Merging was introduced to address the problem with a high number > of LSPs in the core. How is the n-squared problem addressed in > T-MPLS? > > Note: It is not a given that non-merging of LSPs from a protocol > procedural or processing point of view necessarily is less > complex than a merging variant. > > Reserved labels > --------------- > MPLS reserves label values 0-15 for special use. T-MPLS at one point > also intended to reserve values 16-31 for similar use. It has been > pointed out that this will make all existing MPLS implementations > incompatible with T-MPLS. > > Labels 16-31 are said to be for further study. Some comments to the > MPLS mailing list indicates that there is no plans to assign any > semantics to labels 16-31. What is the reason to mention them if > this is the case. > > In particular does the statement imply that these label values > should be > reserved. It is our opinion that: > > 1) If they are reserved then T-MPLS is incompatible with MPLS in a > number of scenarios. It also would mean that T-MPLS is not a > subset > of MPLS (over and above the issue cited below). > > 2) If they are not reserved, reserving them in the future would cause > intolerable deployment difficulties. > > In conclusion you should either say the labels are reserved and > clearly > declare that T-MPLS is not compatible with MPLS or remove the FFS text > entirely. > > > True subset of MPLS > ------------------- > It has been claimed that T-MPLS is a true subset of MPLS, yet the > Y.1711 seems to be a part of T-MPLS. Y.1711 is not part of MPLS. > > If what is wanted is really a subset of MPLS, we believe several > aspects > has to be made clear > - the exact relationship to MPLS > - that enough functionality is there to make interoperability with > MPLS possible > - the MPLS OAM specification in RFC4377 has to be addressed > > There is previous art in defining similar "subsets" of MPLS, > e.g. "draft-loa-mpls-cap-set-01.txt" and > "draft-rosen-mpls-profiles-00.txt"; these efforts did not go very far > since it was not obvious that they solved a real problem. > In general it would be good to have a clear problem statement for > T-MPLS. > > T-MPLS trademark > ---------------- > It has been brought to our notice that one of the parties active > in developing the T-MPLS has a trademark on "T-MPLS". We don't > know if this is a serious matter. Our postion on this is that > IETF owns MPLS, though we never tried to trademark it, we are for > open standards, and would see any attempt to use the MPLS and > GMPLS technologies by means of trademarking as hostile. > > Interoperability at the MPLS / T-MPLS interface > ----------------------------------------------- > Several of the issues we have are for the interoperability between > a T-MPLS device and an MPLS device. We can't see that these issues > are discussed anywhere. We believe that these issues need to be > addressed at least to make sure that there is no interoperability > problems. > > Per platform or per interface labels > +++++++++++++++++++++++++++++++++++ > For a local link repair it is crucial whether the box you are > talking to uses a per platform or per link label space. > > Note that if T-MPLS were to reserve labels 16-31 > then T-MPLS cannot have a per platform label space if the platform > also > has mpls interfaces. These labels are *NOT* reserved by MPLS and are > extremely likely to be allocated. > > I would also like it made clear as to whether they envision T-MPLS > diverging on the interpretation of the EOS bit and the QoS/Exp bits. > > Global labels > +++++++++++++ > T-MPLS renames per platform labels "global labels", since global is > an IETF term used to signify domain wide labels, is there a > rationale for this renaming of platform to global? T-MPLS should > align with the MPLS terminology. > > TTL management and LSP tunnels > ++++++++++++++++++++++++++++++ > RFC3443 describes how TTLs are handled in LSPs tunnels. The G.8110.1 > state that it only supports RFC3443 for pipes and short pipes only. > This is a potential incompatibility with MPLS over the interface > between MPLS and T-MPLS networks. > > Interoperability over interface between MPLS and T-MPLS networks > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > Some of the MPLS applications has been designed with certain MPLS > features taken for granted, e.g.: > > - pseudowires assumes per platform labels > - VPN assumes PHP > - etc > > for these applications to work as before a T-MPLS box will need to > have two types of interfaces. One interface that works as specified > in T-MPLS and another interface that works as specified in MPLS. > The T-MPLS needs to translate between the T-MPLS and the MPLS > environment since this is not in the MPLS specifications from start. > > > _______________________________________________ > mpls mailing list > mpls@lists.ietf.org > https://www1.ietf.org/mailman/listinfo/mpls _______________________________________________ mpls mailing list mpls@lists.ietf.org https://www1.ietf.org/mailman/listinfo/mpls
- [mpls] consolidated response to Q12/15 on T-MPLS Loa Andersson
- Re: [mpls] consolidated response to Q12/15 on T-M… Andrew G. Malis
- Re: [mpls] consolidated response to Q12/15 on T-M… Scott W Brim
- Re: [mpls] consolidated response to Q12/15 on T-M… Thomas D. Nadeau
- Re: [mpls] consolidated response to Q12/15 on T-M… Andrew G. Malis
- Re: [mpls] consolidated response to Q12/15 on T-M… Thomas D. Nadeau
- Re: [mpls] consolidated response to Q12/15 on T-M… Scott W Brim
- RE: [mpls] consolidated response to Q12/15 on T-M… Brungard, Deborah A, ALABS
- Re: [mpls] consolidated response to Q12/15 on T-M… Loa Andersson
- Re: [mpls] consolidated response to Q12/15 on T-M… Thomas D. Nadeau