1 Scope
2 References
3 Definitions
3.1 Terms defined elsewhere
3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Conventions
6 Applications of OTN shared ring protection
6.1 Attributes of shared ring protection
6.2 Protection classifications
6.3 Applications considerations
6.4 Use of extra traffic
7 ODU SRP
7.1 Two and four-fibre ODU SRP types
7.2 Wrapping application of ODU SRP
7.3 Steering application of ODU shared ring protection
8 Interworking architectures
8.1 Single node interconnection
8.2 Dual node interconnection
Annex A – Network objectives
Appendix I – Examples of protection switching in an ODU SRP
I.1 Unidirectional signal fail (span) in a four-fibre
ring
I.2 Unidirectional signal fail (ring)
I.3 Bidirectional signal fail (ring)
I.4 Unidirectional signal degrade (ring)
I.5 Node failure
I.6 Unidirectional SF-R pre-empting a unidirectional
SD-S on non-adjacent spans
I.7 Unidirectional SF-S pre-empting a unidirectional
SF-R on adjacent spans – SF-S and SF-R detected at non-adjacent nodes
I.8 Unidirectional SF-R pre-empting a unidirectional
SD-S on adjacent spans
I.9 Unidirectional SF-R coexisting with a unidirectional
SF-R on non-adjacent spans
I.10 Node failure on a ring with extra traffic capability
I.11 Unidirectional SF-S pre-empting a unidirectional SF-R on
adjacent spans– SF-S and SF-R detected at adjacent nodes
Appendix II – Generalized squelching logic
II.1 Squelching for unidirectional (and bidirectional) circuits
II.2 Squelching of multiply dropped and multiply sourced
unidirectional circuits
Appendix III – Ring configuration examples
III.1 2-fibre/2-lambda, 2-fibre/4-lambda and 4-fibre/4-lambda SRP-p
Ring (22SRP-p, 24SRP‑p, 44SRP-p) configurations example
III.2 2 fibres/4 lambda, 4-fibre/4-lambda SRP-1 Ring (24SRP-1,
44SRP-1) configuration example
III.3 ODU SRP group protection example