MPLS Traffic Engineering Soft Preemption
RFC 5712

Document Type RFC - Proposed Standard (January 2010; No errata)
Last updated 2013-03-02
Stream IETF
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Stream WG state WG Document
Consensus Unknown
Document shepherd No shepherd assigned
IESG IESG state RFC 5712 (Proposed Standard)
Telechat date
Responsible AD Adrian Farrel
Send notices to mpls-chairs@ietf.org, draft-ietf-mpls-soft-preemption@ietf.org
Internet Engineering Task Force (IETF)                     M. Meyer, Ed.
Request for Comments: 5712                               British Telecom
Category: Standards Track                               JP. Vasseur, Ed.
ISSN: 2070-1721                                      Cisco Systems, Inc.
                                                            January 2010

                MPLS Traffic Engineering Soft Preemption

Abstract

   This document specifies Multiprotocol Label Switching (MPLS) Traffic
   Engineering Soft Preemption, a suite of protocol modifications
   extending the concept of preemption with the goal of reducing or
   eliminating traffic disruption of preempted Traffic Engineering Label
   Switched Paths (TE LSPs).  Initially, MPLS RSVP-TE was defined with
   support for only immediate TE LSP displacement upon preemption.  The
   utilization of a reroute request notification helps more gracefully
   mitigate the reroute process of preempted TE LSP.  For the brief
   period soft preemption is activated, reservations (though not
   necessarily traffic levels) are in effect under-provisioned until the
   TE LSP(s) can be rerouted.  For this reason, the feature is
   primarily, but not exclusively, interesting in MPLS-enabled IP
   networks with Differentiated Services and Traffic Engineering
   capabilities.

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 5741.

   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/rfc5712.

Meyer & Vasseur             Standards Track                     [Page 1]
RFC 5712                MPLS-TE Soft Preemption             January 2010

Copyright Notice

   Copyright (c) 2010 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Introduction ....................................................3
   2. Terminology .....................................................3
      2.1. Acronyms and Abbreviations .................................3
      2.2. Nomenclature ...............................................4
      2.3. Requirements Language ......................................4
   3. Motivations .....................................................4
   4. RSVP Extensions .................................................5
      4.1. SESSION-ATTRIBUTE Flags ....................................5
      4.2. Path Error - "Reroute Request Soft Preemption"
           Error Value ................................................5
   5. Mode of Operation ...............................................6
   6. Elements Of Procedures ..........................................7
      6.1. On a Soft Preempting LSR ...................................7
      6.2. On Head-end LSR of a Soft Preempted TE LSP .................9
   7. Interoperability ...............................................10
   8. Management .....................................................10
   9. IANA Considerations ............................................11
      9.1. New Session Attribute Object Flag .........................11
      9.2. New Error Sub-Code Value ..................................11
   10. Security Considerations .......................................11
   11. Acknowledgements ..............................................12
   12. Contributors ..................................................12
   13. References ....................................................12
      13.1. Normative References .....................................12
      13.2. Informative References ...................................13

Meyer & Vasseur             Standards Track                     [Page 2]
RFC 5712                MPLS-TE Soft Preemption             January 2010

1.  Introduction
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