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 Network objectives
8 Protection characteristics
8.1 Monitoring methods and conditions
9 Protection group commands
9.1 End-to-end commands and states
9.2 Local commands
10 Protection architectures
10.1 Unidirectional and bidirectional switching
10.2 Need for APS communication
10.3 Revertive and non-revertive switching
10.4 Provisioning mismatches
10.5 Protection switching trigger
10.6 Protection switching models
11 APS Protocol
11.1 APS format
11.2 1-phase APS protocol
11.3 Request type
11.4 Protection types and bridge type
11.5 Requested signal
11.6 Bridged signal
11.7 Control of bridge
11.8 Control of selector
11.9 Signal fail of the protection transport entity
11.10 Equal priority requests
11.11 Command acceptance and retention
11.12 Hold-off timer
11.13 Wait-to-restore timer
11.14 Exercise operation
11.15 Failure of protocol defects
11.16 Signal degrade of the protection transport entity
Annex A – State transition tables of protection switching
A.1 State transition for 1:1 bidirectional switching with revertive
mode
A.2 State transition for 1:1 bidirectional switching with
non-revertive mode
A.3 State transition for 1+1 bidirectional switching with revertive
mode
A.4 State transition for 1+1 bidirectional switching with
non-revertive mode
A.5 State transition for 1+1 unidirectional switching with
revertive mode
A.6 State transition for 1+1 unidirectional switching with
non-revertive mode
Appendix I – Operation example of 1‑phase APS protocol
I.1 Introduction
I.2 Example scenario
I.3 APS protocol examples
Appendix II – Interaction between Ethernet protection switching and STP
Appendix III – MIPs for protection switching environment
III.1 Introduction
III.2 Considerations
III.3 Configuration examples
Appendix IV – State transition diagrams using SDL
IV.1 Introduction
IV.2 SDL diagrams