1 Scope
2 Abbreviations and acronyms
3 Background – Fibre protection
3.1 PON system components – Failure rates
3.2 Failures in time and mean time between failures
4 PON protection use cases
4.1 Large numbers of subscribers per PON line card
4.2 Business and mobile backhaul services
4.3 PON reach extenders
4.4 Emergency services
4.5 PON maintenance
5 Protection architectures
5.1 Type A
5.2 Type B
5.3 Dual‑parented type B protection
5.4 Type C protection
5.5 Extra traffic for type C protection
5.6 Type C protection using link aggregation
5.7 Type D – Deprecated
5.8 Type B with N:1
6 Availability and switching speed goals
6.1 Availability in an unprotected PON
6.2 Assumptions for availability calculations
6.3 Availability of an unprotected PON
6.4 Protection path monitoring
6.5 Switching speed and impact on availability
7 Fast failure detection
8 Fast protection switchover mechanisms
8.1 Ranging before switchover (pre-ranging)
8.2 Ranging after switchover (limited re-ranging)
8.3 No pre-configuration of standby OLT EqD values per ONU (fast
ranging)
8.4 Equalization-delay-agnostic protection switch
8.5 Typical practice of fast protection switchover mechanisms and
viability analysis
9 Recommended architectures versus use cases
10 Ethernet linear protection switching to support type B PON protection
10.1 Protection switching service characteristics
10.2 OLT PON port type B Protection State Machine
10.3 Initial connection configuration
10.4 Description of end to end protection switching
Bibliography