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