Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS)
RFC 4427

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• 06

Network Working Group                                     E. Mannie, Ed.
Request for Comments: 4427                                      Perceval
Category: Informational                            D. Papadimitriou, Ed.
                                                                 Alcatel
                                                              March 2006

           Recovery (Protection and Restoration) Terminology
        for Generalized Multi-Protocol Label Switching (GMPLS)

Status of This Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   This document defines a common terminology for Generalized Multi-
   Protocol Label Switching (GMPLS)-based recovery mechanisms (i.e.,
   protection and restoration).  The terminology is independent of the
   underlying transport technologies covered by GMPLS.

Mannie & Papadimitriou       Informational                      [Page 1]
RFC 4427               GMPLS Recovery Terminology             March 2006

Table of Contents

   1. Introduction ....................................................3
   2. Contributors ....................................................4
   3. Conventions Used in this Document ...............................5
   4. Recovery Terminology Common to Protection and Restoration .......5
      4.1. Working and Recovery LSP/Span ..............................6
      4.2. Traffic Types ..............................................6
      4.3. LSP/Span Protection and Restoration ........................6
      4.4. Recovery Scope .............................................7
      4.5. Recovery Domain ............................................8
      4.6. Recovery Types .............................................8
      4.7. Bridge Types ..............................................10
      4.8. Selector Types ............................................10
      4.9. Recovery GMPLS Nodes ......................................11
      4.10. Switch-over Mechanism ....................................11
      4.11. Reversion operations .....................................11
      4.12. Failure Reporting ........................................12
      4.13. External commands ........................................12
      4.14. Unidirectional versus Bi-Directional Recovery Switching ..13
      4.15. Full versus Partial Span Recovery Switching ..............14
      4.16. Recovery Schemes Related Time and Durations ..............14
      4.17. Impairment ...............................................15
      4.18. Recovery Ratio ...........................................15
      4.19. Hitless Protection Switch-over ...........................15
      4.20. Network Survivability ....................................15
      4.21. Survivable Network .......................................16
      4.22. Escalation ...............................................16
   5. Recovery Phases ................................................16
      5.1. Entities Involved During Recovery .........................17
   6. Protection Schemes .............................................17
      6.1. 1+1 Protection ............................................18
      6.2. 1:N (N >= 1) Protection ...................................18
      6.3. M:N (M, N > 1, N >= M) Protection .........................18
      6.4. Notes on Protection Schemes ...............................19
   7. Restoration Schemes ............................................19
      7.1. Pre-Planned LSP Restoration ...............................19
           7.1.1. Shared-Mesh Restoration ............................19
      7.2. LSP Restoration ...........................................20
           7.2.1. Hard LSP Restoration ...............................20
           7.2.2. Soft LSP Restoration ...............................20
   8. Security Considerations ........................................20
   9. References .....................................................20
      9.1. Normative References ......................................20
      9.2. Informative References ....................................20
   10. Acknowledgements ..............................................21

Mannie & Papadimitriou       Informational                      [Page 2]
RFC 4427               GMPLS Recovery Terminology             March 2006

1.  Introduction

   This document defines a common terminology for Generalized Multi-
   Protocol Label Switching (GMPLS)-based recovery mechanisms (i.e.,
   protection and restoration).

   The terminology proposed in this document is independent of the
   underlying transport technologies and borrows from the G.808.1 ITU-T
   Recommendation [G.808.1] and from the G.841 ITU-T Recommendation
   [G.841].  The restoration terminology and concepts have been gathered