1
Scope
2 References
3 Terms and definitions
4 Abbreviations
5 Synchronization principles
5.1 Network synchronization
5.2 Synchronization distribution
trails
5.3 Synchronization interfaces
5.3.1 Overview
5.3.2 STM-N
5.3.3 2 Mbit/s
5.3.4 2 MHz
5.3.5 34 Mbit/s and 140 Mbit/s with 125 ms frame structure
5.3.6 1.5 Mbit/s
5.3.7 64 kHz
5.3.8 6312 kHz
5.4 Clock-Source Quality-Level
5.4.1 Clock-Source Quality-Level Definitions
5.4.2 Hierarchy of Clock-Sources Quality Levels (QL) or (CS_QL)
5.4.3 Forcing and defaulting of Clock-Source Quality-Levels
5.4.4 Application of Quality Level "Unknown"
5.4.5 Application of Quality Level "Provisioned"
5.5 Synchronization Status Messages
(SSM) and Timing Marker (TM) channels
5.5.1 SSM and TM message sets
5.5.2 SSM and TM code word generation
5.5.3 SSM and TM code word interpretation
5.6 Selection process
5.7 Signal fail
5.8 Hold-off time
5.9 Wait to restore time
5.10 Synchronization source priorities
5.11 External commands
5.11.1 External commands per nominated
synchronization source
5.11.2 External commands per selection process
5.12 Automatic reference selection
process
5.12.1 QL‑enabled mode
5.12.2 QL‑disabled mode
5.13 Timing loop prevention
5.13.1 Station clock input used as a source for station clock output
5.13.2 Between NEs with SEC type clocks
5.13.3 Between NEs with a SEC clock and a NE or SASE/BITS with a SSU/ST2 clock
and only one link
5.13.4 Between NEs with a SEC clock and a NE or SASE/BITS with a SSU clock and
several links
5.14 Delay times for NEs with
SEC/ST3/SIC
5.14.1 Delay times for NEs with SEC in
Option I and III SDH synchronization networks
5.14.2 Delay times for NEs with ST3/SMC in Option II SDH synchronization
networks
5.15 Delay times for NEs with SSU/ST2
or for SASE/BITS
5.16 Synchronization layer functions
5.17 Overview of the processes
performed within the atomic functions
5.18 Interworking between
Option I, II and III synchronization networks
6 Synchronization distribution layer
atomic functions
6.1 SD Connection function (SD_C)
6.2 SD trail termination functions
6.2.1 SD trail termination source function (SD_TT_So)
6.2.2 SD trail termination sink function (SD_TT_Sk)
6.3 SD adaptation functions
6.3.1 SD layer to NS layer SEC quality adaptation source function (SD/NS‑SEC-A_So)
6.3.2 SD layer to NS layer SEC quality adaptation sink function (SD/NS‑SEC_A_Sk)
6.3.3 SD layer to NS layer SMC quality adaptation source function (SD/NS‑SMC_A_So)
6.3.4 SD layer to NS layer SMC quality adaptation sink function (SD/NS‑SMC_A_Sk)
6.3.5 SD layer to NS layer ST3 quality adaptation
source function (SD/NS‑ST3_A_So)
6.3.6 SD layer to NS layer ST3 quality adaptation sink function (SD/NS‑ST3_A_Sk)
6.3.7 SD layer to NS layer ST3E quality adaptation source function (SD/NS‑ST3E_A_So)
6.3.8 SD layer to NS layer ST3E quality adaptation sink function (SD/NS‑ST3E_A_Sk)
6.3.9 SD layer to NS layer SSU quality adaptation source function (SD/NS‑SSU_A_So)
6.3.10 SD layer to NS layer SSU quality
adaptation sink function (SD/NS‑SSU_A_Sk)
6.3.11 SD layer to NS layer ST2 quality adaptation source function (SD/NS‑ST2_A_So)
6.3.12 SD layer to NS layer ST2 quality adaptation sink function (SD/NS‑ST2_A_Sk)
6.3.13 SD layer to NS layer PRC quality adaptation source function (SD/NS‑PRC_A_So)
6.3.14 SD layer to NS layer PRS quality adaptation source function (SD/NS‑PRS_A_So)
6.3.15 SD layer to NS layer adaptation source function (SD/NS_A_So)
7 Network synchronization layer
atomic functions
7.1 NS_connection functions (NS_C)
8 Transport layer to SD layer atomic
function
8.1 STM‑n multiplex section
adaptation functions
8.1.1 STM‑N multiplex section to SD adaptation source (MSn/SD_A_So)
8.1.2 STM‑N multiplex section to SD adaptation sink (MSn/SD_A_Sk)
8.2 Pqs adaptation functions
8.2.1 Pqs to SD adaptation source (Pqs/SD_A_So)
8.2.2 Pqs to SD adaptation sink (Pqs/SD_A_Sk)
8.3 P12s layer adaptation functions
8.3.1 P12s layer adaptation source functions
8.3.2 P12s layer adaptation sink functions
8.4 T12 layer adaptation functions
8.4.1 T12 to SD adaptation source (T12/SD_A_So)
8.4.2 T12 to SD adaptation sink (T12/SD_A_Sk)
8.5 P11s layer adaptation functions
8.5.1 P11s to SD adaptation source (P11s/SD_A_So)
8.5.2 P11s to SD adaptation sink (P11s/SD_A_Sk)
8.6 T01 layer adaptation functions
8.6.1 T01 to SD
adaptation source (T01/SD_A_So)
8.6.2 T01 to SD adaptation sink (T01/SD_A_Sk)
8.7 T02 layer adaptation functions
8.7.1 T02 to SD adaptation source (T02/SD_A_So)
8.7.2 T02 to SD
adaptation sink (T02/SD_A_Sk)
8.8 T21 layer adaptation functions
8.8.1 T21 to SD adaptation source (T21/SD_A_So)
8.8.2 T21 to SD adaptation sink (T21/SD_A_Sk)
9 Equipment clock to transport
layers clock adaptation functions
9.1 STM-N layer
9.1.1 STM‑N layer clock adaptation source (MSn-LC_A_So)
9.2 VC layers
9.2.1 VC‑n layer clock adaptation source (Sn-LC_A_So)
9.2.2 VC‑m layer clock adaptation source (Sm-LC_A_So)
9.3 Pxx layers
9.3.1 Pqs layer clock adaptation source (Pqs-LC_A_So)
9.3.2 P12s layer clock adaptation source (P12s-LC_A_So)
9.3.3 P11s layer clock adaptation source (P11s-LC_A_So)
9.4 T12 layer
9.4.1 T12 layer clock adaptation source
(T12-LC_A_So)
9.5 T01 layer
9.5.1 T01 layer clock adaptation source
(T01-LC_A_So)
9.6 T02 layer
9.6.1 T02 layer clock adaptation source
(T02-LC_A_So)
9.7 T21 layer
9.7.1 T21 layer clock adaptation source
(T21-LC_A_So)
10 T12 Section Layer Functions
10.1 T12 Connection function T12_C
10.2 T12 Trail Termination functions
10.2.1 T12 Trail Termination Source T12-Z_TT_So
10.2.2 T12 Trail Termination Sink T12-Z_TT_Sk
11 T01 Section Layer Functions
11.1 T01 Connection function T01_C
11.2 T01 Trail Termination functions
11.2.1 T01 Trail Termination Source T01_TT_So
11.2.2 T01 Trail Termination Sink T01_TT_Sk
12 T02 Section Layer Functions
12.1 T02 Connection function T02_C
12.2 T02 Trail Termination functions
12.2.1 T02 Trail Termination Source T02_TT_So
12.2.2 T02 Trail Termination Sink T02_TT_Sk
13 T21 Section Layer Functions
13.1 T21 Connection function T21_C
13.2 T21 Trail Termination functions
13.2.1 T21 Trail Termination Source T21_TT_So
13.2.2 T21 Trail Termination Sink T21_TT_Sk
Annex A – Synchronization selection process
Appendix I – Transport layer models for synchronization
information
Appendix II – Examples of synchronization functionality
in the NE
II.1 Examples of synchronization functionality in the NE for
Option I networks
II.2 Examples of synchronization
functionality in the NE for Option II networks
II.3 Examples of synchronization
functionality in the NE for Option III networks
Appendix III – Delay time allocation for Option I
and III SDH networks
III.1 Delay and processing times for the
synchronization selection process
III.2 Non‑switching message delay
TNSM
III.3 Switching message delay TSM
III.4 Holdover message delay THM
III.5 Wait to restore time TWTR
Appendix IV – Interworking of SDH Option II
Equipment supporting Second Generation SSM and First Generation SSM using a
translation function