Recommendation ITU-T G.8032/Y.1344 (03/2020) Ethernet ring protection switching
Summary
History
FOREWORD
Table of Contents
1 Scope
2 References
3 Definitions
     3.1 Terms defined elsewhere
     3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Conventions
     5.1 Representation of octets
6 Introduction
7 Ring protection characteristics
     7.1 Monitoring methods and conditions
     7.2 Ethernet traffic and bandwidth consideration
     7.3 Ethernet ring protection switching performance
8 Ring protection conditions and commands
9 Ring protection architectures
     9.1 Revertive and non-revertive switching
     9.2 Protection switching triggers
          9.2.1 Signal fail declaration conditions
     9.3 Protection switching models on a single Ethernet ring
     9.4 Traffic channel blocking
     9.5 R-APS channel blocking
     9.6 Filtering database flush
     9.7 Ethernet ring protection switching models for interconnection
          9.7.1 Ring interconnection model with an R-APS virtual channel
          9.7.2 Ring interconnection model without an R-APS virtual channel
          9.7.3 Guidelines for using the ring interconnection model with or without an R-APS virtual channel
10 Protection control protocol
     10.1 Principles of operations
          10.1.1 Priority logic
          10.1.2 R-APS request processing
          10.1.3 R-APS message transmission
          10.1.4 Delay timers
          10.1.5 Guard timer
          10.1.6 Validity check
          10.1.7 Local defect logic
          10.1.8 Hold-off timer
          10.1.9 Local priority logic
          10.1.10 Flush logic
          10.1.11 Interconnection flush logic
          10.1.12 Topology change propagation
          10.1.13 Backward compatibility logic
          10.1.14 R-APS block logic
     10.2 Protection switching behaviour
          10.2.1 Protection switching – Link signal fail
          10.2.2 Protection switching – Recovery
               10.2.2.1 Revertive behaviour
               10.2.2.2 Non-revertive behaviour
          10.2.3 Protection switching – Manual switch
               10.2.3.1 Manual switch – clearing
          10.2.4 Protection switching – Forced switch
               10.2.4.1 Forced switch – clearing
     10.3 R-APS format
     10.4 Failure of protocol defect
Appendix I  Ring protection network objectives
Appendix II  Ethernet ring network objectives
Appendix III  Ring protection scenarios
Appendix IV  Considerations for different timers
     IV.1 State machine use of timers
     IV.2 Guard timer use to block outdated R-APS messages
Appendix V
Appendix VI
Appendix VII
Appendix VIII  Flush optimization
     VIII.1 Flushing FDB consideration
     VIII.2 Scenarios of unnecessary FDB flushing
     VIII.3 Example of FDB flush optimization
     VIII.4 Additional definition of the ERP control process model and state machine
     VIII.5 DNF status
Appendix IX
Appendix X
Appendix XI
Bibliography