ITU-T G.872

qijiayuan

ARCHITECTURE OF OPTICAL TRANSPORT NETWORKS
CONTENTS
Page
1 Scope ..........................................................................................................................1
2 References .................................................................................................................. 1
3 Terms and definitions................................................................................................. 2
4 Abbreviations ............................................................................................................. 3
5 Transport functional architecture of optical networks................................................ 4
5.1 General principles....................................................................................................... 4
5.2 Optical transport network layered structure ............................................................... 5
5.3 Optical channel layer network.................................................................................... 6
5.3.1 Optical channel trail termination................................................................... 7
5.3.2 OCh transport entities ................................................................................... 8
5.4 Optical multiplex section layer network..................................................................... 8
5.4.1 Optical multiplex section trail termination ................................................... 9
5.4.2 OMS transport entities .................................................................................. 9
5.5 Optical transmission section layer network................................................................ 9
5.5.1 Optical transmission section trail termination .............................................. 10
5.5.2 OTS transport entities ................................................................................... 11
5.6 Client/server associations ........................................................................................... 11
5.6.1 OCh/client adaptation ................................................................................... 11
5.6.2 OMS/OCh adaptation.................................................................................... 11
5.6.3 OTS/OMS adaptation.................................................................................... 12
5.7 Optical network topology........................................................................................... 12
5.7.1 Unidirectional and bidirectional connections and trails................................ 12
5.7.2 Point-to-multipoint connections and trails.................................................... 12
6 Optical network management..................................................................................... 13
6.1 Generic requirements ................................................................................................. 13
6.1.1 Generic fault, configuration and performance management......................... 13
6.1.2 Generic management communications ......................................................... 14
6.1.3 Generic client/server interaction management.............................................. 14
6.2 Optical layer network management requirements...................................................... 14
6.2.1 Connection supervision................................................................................. 15
6.2.2 Signal quality supervision............................................................................. 18
6.2.3 Adaptation management................................................................................ 18
6.2.4 Protection control .......................................................................................... 18
6.2.5 Management communications ...................................................................... 18
6.2.6 Other communication needs.......................................................................... 19
6.3 Connection supervision techniques and applications................................................. 19
6.3.1 Inherent monitoring....................................................................................... 19
6.3.2 Non-intrusive monitoring.............................................................................. 19
6.3.3 Intrusive monitoring...................................................................................... 20
6.3.4 Sublayer monitoring...................................................................................... 20
6.3.5 Monitoring of unused connections................................................................ 20
6.3.6 Tandem connection monitoring .................................................................... 20
7 Optical network survivability techniques................................................................... 21
7.1 Protection ...................................................................................................................21
7.2 Network restoration.................................................................................................... 23
8 Interconnection and interworking between different administrative domains ........... 23
Annex A – Impairment mitigation and regeneration............................................................... 27
Appendix I – Examples of Optical Network functionality...................................................... 28
I.1 Wavelength conversion .............................................................................................. 28
I.2 Cross-connect ............................................................................................................. 29
I.3 Regeneration............................................................................................................... 29