Table of Contents

Foreword
1 Scope
2 Normative references
3 Abbreviations
4 Definitions and classifications
  4.1 General definitions
  4.2 Ring definitions
  4.3 Protection classifications
5 Multiplex section trail protection protocols
  5.1 Multiplex section trail linear protection
  5.2 2-fibre multiplex section trail shared protection
      ring
  5.3 4-fibre multiplex section trail shared protection
      ring
  5.4 2-fibre multiplex section trail dedicated protection
      ring
  6.1 LO/HO trail protection
  6.2 LO/HO SNC protection
Annex A (normative): Squelching mechanism in MS-Shared
        Protection Rings
    A.1 Squelching of HO traffic
Annex B (informative): Examples of protection switching
        in an MS shared protection ring
    B.1 Unidirectional signal fail (ring)
    B.2 Bi-directional signal fail (ring)
    B.3 Unidirectional signal degrade (ring)
    B.4 Detection and clearing of a unidirectional
        SF-R in presence of another unidirectional
        SF-R on a non-adjacent span
    B.5 Unidirectional SF-R pre-empting a
        unidirectional SD-R on a non-adjacent span
    B.6 Unidirectional SD-R pre-empting a
        unidirectional MS-R on an adjacent span
Annex C (informative): Bibliography
History

Abstract

Specifies the Automatic Protection Switching (APS) requirements, switching initiation criteria, and the APS protocols of Synchronous Digital Hierarchy (SDH) multiplex section shared protection ring, multiplex section dedicated protection ring, multiplex section linear protection, and path trail and Sub-Network Connection (SNC) protection schemes.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	European Telecommunications Standards Institute
Pages
ISBN
Committee	TM 3
Supersedes	PRETS 300 746 : DEC 96