RSVP Extensions for Reoptimization of Loosely Routed Point-to-Multipoint Traffic Engineering Label Switched Paths (LSPs)
RFC 8149
Internet Engineering Task Force (IETF) T. Saad, Ed.
Request for Comments: 8149 R. Gandhi, Ed.
Category: Standards Track Z. Ali
ISSN: 2070-1721 Cisco Systems, Inc.
R. Venator
Defense Information Systems Agency
Y. Kamite
NTT Communications Corporation
April 2017
RSVP Extensions for Reoptimization of Loosely Routed
Point-to-Multipoint Traffic Engineering Label Switched Paths (LSPs)
Abstract
The reoptimization of a Point-to-Multipoint (P2MP) Traffic
Engineering (TE) Label Switched Path (LSP) may be triggered based on
the need to reoptimize an individual source-to-leaf (S2L) sub-LSP or
a set of S2L sub-LSPs, both using the Sub-Group-based reoptimization
method, or the entire P2MP-TE LSP tree using the Make-Before-Break
(MBB) method. This document discusses the application of the
existing mechanisms for path reoptimization of loosely routed Point-
to-Point (P2P) TE LSPs to the P2MP-TE LSPs, identifies issues in
doing so, and defines procedures to address them. When reoptimizing
a large number of S2L sub-LSPs in a tree using the Sub-Group-based
reoptimization method, the S2L sub-LSP descriptor list may need to be
semantically fragmented. This document defines the notion of a
fragment identifier to help recipient nodes unambiguously reconstruct
the fragmented S2L sub-LSP descriptor list.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8149.
Saad, et al. Standards Track [Page 1]
RFC 8149 P2MP-TE Loosely Routed LSPs April 2017
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Table of Contents
1. Introduction ....................................................3
2. Conventions Used in This Document ...............................4
2.1. Key Word Definitions .......................................4
2.2. Abbreviations ..............................................4
2.3. Terminology ................................................4
3. Overview ........................................................5
3.1. Loosely Routed Inter-domain P2MP-TE LSP Tree ...............5
3.2. Existing Mechanism for Tree-Based P2MP-TE LSP
Reoptimization .............................................6
3.3. Existing Mechanism for Sub-Group-Based P2MP-TE LSP
Reoptimization .............................................7
4. Signaling Extensions for Loosely Routed P2MP-TE LSP
Reoptimization ..................................................8
4.1. Tree-Based Reoptimization ..................................8
4.2. Sub-Group-Based Reoptimization Using Fragment Identifier ...9
5. Message and Object Definitions .................................11
5.1. "P2MP-TE Tree Re-evaluation Request" Flag .................11
5.2. "Preferable P2MP-TE Tree Exists" Path Error Sub-code ......11
5.3. Fragment Identifier for S2L Sub-LSP Descriptor ............11
6. Compatibility ..................................................12
7. IANA Considerations ............................................13
7.1. "P2MP-TE Tree Re-evaluation Request" Flag .................13
7.2. "Preferable P2MP-TE Tree Exists" Path Error Sub-code ......13
7.3. Fragment Identifier for S2L Sub-LSP Descriptor ............14
8. Security Considerations ........................................14
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