Applicability of MPLS Transport Profile for Ring Topologies
Draft of message to be sent after approval:
From: The IESG <email@example.com> To: IETF-Announce <firstname.lastname@example.org> Cc: RFC Editor <email@example.com>, mpls mailing list <firstname.lastname@example.org>, mpls chair <email@example.com> Subject: Document Action: 'Applicability of MPLS-TP Linear Protection for Ring Topologies' to Informational RFC (draft-ietf-mpls-tp-ring-protection-06.txt) The IESG has approved the following document: - 'Applicability of MPLS-TP Linear Protection for Ring Topologies' (draft-ietf-mpls-tp-ring-protection-06.txt) as Informational RFC This document is the product of the Multiprotocol Label Switching Working Group. The IESG contact persons are Adrian Farrel and Stewart Bryant. A URL of this Internet Draft is: http://datatracker.ietf.org/doc/draft-ietf-mpls-tp-ring-protection/
Technical Summary This document presents an applicability of existing MPLS protection mechanisms, both local and end-to-end, to Multi-Protocol Label Switching Transport Profile (MPLS-TP) in ring topologies. This document does not propose any new mechanisms or protocols. Protection on rings offers a number of opportunities for optimization as the protection choices are starkly limited (all traffic traveling one way around a ring can only be switched to travel the other way on the ring), but also suffers from some complications caused by the limitations of the topology. Requirements for MPLS-TP protection especially for protection in ring topologies are discussed in "Requirements of an MPLS Transport Profile" (RFC 5654) and "MPLS Transport Profile (MPLS-TP) Survivability Framework" (RFC 6372). This document shows how MPLS-TP linear protection as defined in RFC 6378 can be applied to single ring topologies, discusses how most of the requirements are met, and describes scenarios in which the function provided by applying linear protection in a ring topology falls short of some of the requirements. Working Group Summary This document was the subject of considerable debate in the MPLS working group. There was some concern about whether this work prohibited or devalued the development of specialised protection techniques for deployment in ring topologies. The document was re-worked to make it clear that it is basically an applicability statement showing how linear protection defined in RFC 6378 can be applied to ring topologies, what function can be achieved, and what issues remain. It was made clear to the working group that specialist ring protection techniques were still in scope for the working group provided that they demonstrate improvements over the application of linear protection, and provided they can interwork with general protection in the wider MPLS-TP network. A second WG last call was held and the document gained consensus. Please see RFC editor note for a commentary on the number of front-page authors. Document Quality This an informational document, it describes how the technologies defined in earlier RFCs can be applied to ring topologies. The document has been reviewed needed, the working group last call was brought to the attention of SG15 in ITU-T. Personnel Loa Andersson (firstname.lastname@example.org) is the document shepherd Adrian Farrel (Adrian@olddog.co.uk) is the Responsible AD RFC Editor Note Please allow an exception to the normal front-page limit so that all eight named authors can be present. The WG chair/ shepherd explains it as follows: > Early 2010 we had 5 or 6 different drafts addressing "mpls-tp- > ring-protection" from one aspect or another. Most of these > drafts had 2 or maybe 3 different authors. > > The WG chairs took an initiative to discuss the possibilities to > merge all drafts into one. The discussion was partially > successful, and all draft but one, were merged into a single > document. Texts from all drafts were merged into draft- > weingarten-mpls-tp-ring-protection (later to be adopted as > the working group draft draft-ietf-mpls-tp-ring-protection. > > The number of authors on the first page reflect text > contributions made to the drafts that were merged. --- You may rename and reposition Section 1.4 according to your style guide. --- If (and only if) you consider it necessary, you may consider some of the text as Tables and apply captions as follows... In Section 3.1 on page 19 "Table x : Backup LSPs for Node Protection" In Section 3.1.1 on page 20 "Table x : Nodes Traversed by Protection: LSPs" In Section 3.1.1 on page 21 "Table x : Bandwidth Utilization on Links During Protection" In Section 3.2.2 on page 25 "Table x : Context Specific Labels for Connected LSPs"