Re: [mpls] I-D ACTION:draft-ietf-mpls-explicit-resource-control-bundle-03.txt
"Adrian Farrel" <adrian@olddog.co.uk> Wed, 02 April 2008 22:15 UTC
Return-Path: <mpls-bounces@ietf.org>
X-Original-To: mpls-archive@megatron.ietf.org
Delivered-To: ietfarch-mpls-archive@core3.amsl.com
Received: from core3.amsl.com (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id C62493A695B; Wed, 2 Apr 2008 15:15:47 -0700 (PDT)
X-Original-To: mpls@core3.amsl.com
Delivered-To: mpls@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id AEDD928C13F for <mpls@core3.amsl.com>; Wed, 2 Apr 2008 15:15:45 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.03
X-Spam-Level:
X-Spam-Status: No, score=-2.03 tagged_above=-999 required=5 tests=[AWL=0.568, BAYES_00=-2.599, STOX_REPLY_TYPE=0.001]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Iejgc0f7y83M for <mpls@core3.amsl.com>; Wed, 2 Apr 2008 15:15:44 -0700 (PDT)
Received: from asmtp2.iomartmail.com (asmtp2.iomartmail.com [62.128.201.249]) by core3.amsl.com (Postfix) with ESMTP id 310973A6865 for <mpls@ietf.org>; Wed, 2 Apr 2008 15:15:40 -0700 (PDT)
Received: from asmtp2.iomartmail.com (localhost.localdomain [127.0.0.1]) by asmtp2.iomartmail.com (8.12.11.20060308/8.12.8) with ESMTP id m32MFcBL021202 for <mpls@ietf.org>; Wed, 2 Apr 2008 23:15:40 +0100
Received: from your029b8cecfe (dsl-sp-81-140-15-32.in-addr.broadbandscope.com [81.140.15.32]) (authenticated bits=0) by asmtp2.iomartmail.com (8.12.11.20060308/8.12.11) with ESMTP id m32MFaMn021192 for <mpls@ietf.org>; Wed, 2 Apr 2008 23:15:37 +0100
Message-ID: <006001c8950f$12bbba40$0300a8c0@your029b8cecfe>
From: Adrian Farrel <adrian@olddog.co.uk>
To: mpls@ietf.org
References: <20080402191502.6131228C679@core3.amsl.com>
Date: Wed, 02 Apr 2008 23:15:31 +0100
MIME-Version: 1.0
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2900.3138
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198
Subject: Re: [mpls] I-D ACTION:draft-ietf-mpls-explicit-resource-control-bundle-03.txt
X-BeenThere: mpls@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
Reply-To: Adrian Farrel <adrian@olddog.co.uk>
List-Id: Multi-Protocol Label Switching WG <mpls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/mpls>, <mailto:mpls-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/pipermail/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>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: mpls-bounces@ietf.org
Errors-To: mpls-bounces@ietf.org
Hi Anca, Interesting to see this draft back again. I think it expired in April 2007 and I had assumed we had given up on it. A couple of thoughts... === In the terminology section you have: For unnumbered component links, the component link ID is assumed to be unique on an advertising node. I think this reflects exactly what was discussed several IETFs ago (possibly in CCAMP with respect to the hierarchy-bis draft or maybe draft-ietf-ccamp-gmpls-addressing-03). However, don't you need to have some RFC 2119 language here? Failing this assumption will break your draft, so this is a "MUST" in which case I suggest you move it from the Terminology section to the main body of the draft. === More generally, way back in March 2006, in Dallas, CCAMP discussed how to build EROs and RROs in order to qualify this in draft-ietf-ccamp-gmpls-addressing (now RFC 4990). We had a survey and published the results in http://www.watersprings.org/pub/id/draft-farrel-ccamp-ero-survey-00.txt. The conclusion seemed to be that implementations of bundling simply reported (and signaled) component links by including two sequential interface IDs, the first indicating the TE link and the second the component link. There was no need to use different subobject types for these two pieces of information as their ordering and context was sufficient. I recall that in the discussions it was even suggested that it was not necessary to include both the TE link ID and the component link ID as the component link ID actually has global scope even if it does not have global visibility. But the survey seemed to indicate that people wanted to "play safe" and include both identifiers. === Part of the question may hinge on the U-bit that you have defined for your new suobjects. This bit allows different component links to be used in each direction. Have we had a thorough discussion of this requirement? Last time I talked to people about this, it seemed to be the case that, just as we would not split a bidirectional LSP across separate TE links in each direction, we would not split an LSP across separate component links in each direction. After all, component links are just TE links that are bundled for advertisement. It was suggested that component links might be unidirectional components of a bidirectional bundle. But surely, just as with TE links, unidirectional data channels are paired to form bidirectional data links. I note, however, that RFC 4990 decided to allow different component links to be used in each direction with some (rather unclear) suggestion that ordering the subobjects is enough to allow you to determine the direction. === So, we come to the big question. Why do we need to change existing implementations and introduce a different way of encoding EROs and RROs for bundled links? Cheers, Adrian PS. I think that introducing a flag "component link recording desired" is a great idea. ----- Original Message ----- From: <Internet-Drafts@ietf.org> To: <i-d-announce@ietf.org> Cc: <mpls@ietf.org> Sent: Wednesday, April 02, 2008 8:15 PM Subject: [mpls] I-D ACTION:draft-ietf-mpls-explicit-resource-control-bundle-03.txt >A New Internet-Draft is available from the on-line Internet-Drafts > directories. > This draft is a work item of the Multiprotocol Label Switching Working > Group of the IETF. > > Title : Component Link Recording and Resource Control for TE Link Bundles > Author(s) : A. Zamfir > Filename : draft-ietf-mpls-explicit-resource-control-bundle-03.txt > Pages : 12 > Date : 2008-4-2 > > Record Route is a useful administrative tool that has been used > extensively by the service providers. However, when TE links are > bundled, identification of label resource in Record Route Object > (RRO) is not enough for the administrative purpose. Network service > providers would like to know the component link within a TE link that > is being used by a given LSP. In other words, when link bundling is > used, resource recording requires mechanisms to specify the component > link identifier, along with the TE link identifier and Label. As it > is not possible to record component link in the RRO, this draft > defines the extensions to RSVP-TE [RFC3209] and [RFC3473] to specify > component link identifiers for resource recording purposes. > > This draft also defines the Explicit Route Object (ERO) counterpart > of the RRO extension. The ERO extensions are needed to perform > explicit label/ resource control over bundled TE link. Hence, this > document defines the extensions to RSVP-TE [RFC3209] and [RFC3473] to > specify component link identifiers for explicit resource control and > recording over TE link bundles. > > A URL for this Internet-Draft is: > http://www.ietf.org/internet-drafts/draft-ietf-mpls-explicit-resource-control-bundle-03.txt > > Internet-Drafts are also available by anonymous FTP at: > ftp://ftp.ietf.org/internet-drafts/ > > Below is the data which will enable a MIME compliant mail reader > implementation to automatically retrieve the ASCII version of the > Internet-Draft. > -------------------------------------------------------------------------------- > _______________________________________________ > mpls mailing list > mpls@ietf.org > https://www.ietf.org/mailman/listinfo/mpls > _______________________________________________ mpls mailing list mpls@ietf.org https://www.ietf.org/mailman/listinfo/mpls
- [mpls] I-D ACTION:draft-ietf-mpls-explicit-resour… Internet-Drafts
- Re: [mpls] I-D ACTION:draft-ietf-mpls-explicit-re… Adrian Farrel