�1���� Scope
�2���� References
�3���� Terms and
definitions
�4���� Abbreviations
and acronyms
�5���� Synchronization
principles
������� 5.1���� Network
synchronization
������� 5.2���� Synchronization
distribution trails
������� 5.3���� Synchronization
interfaces
������� 5.4���� Clock-source
quality-level
������� 5.5���� Synchronization
status messages (SSMs), extended QL TLV, and timing marker (TM) channels
������� 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
������ 5.12���� Automatic
reference selection process
� �����5.13���� Timing
loop prevention
������ 5.14���� Delay
times for NEs with SEC/ST3/SIC
������ 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
������� 6.3���� SD
adaptation functions
�7���� Network
synchronization layer atomic functions
������� 7.1���� NS_connection
functions (NS_C)
�8���� Transport layer
to SD layer atomic functions
������� 8.1���� STM‑n
multiplex section adaptation functions
������� 8.2���� Pqs
adaptation functions
������� 8.3���� P12s
layer adaptation functions
������� 8.4���� T12
layer adaptation functions
������� 8.5���� P11s
layer adaptation functions
������� 8.6���� T01 layer
adaptation functions
������� 8.7���� T02 layer
adaptation functions
������� 8.8���� T21 layer
adaptation functions
������� 8.9���� ETH layer
adaptation functions
������ 8.10���� OTUk layer
adaptation functions
������ 8.11���� OSC layer
adaptation functions
������ 8.12���� FlexO layer
adaptation functions
������ 8.13���� FlexE layer adaptation functions
�9���� Equipment clock
to transport layers clock adaptation functions
������� 9.1���� STM-N
layer
������� 9.2���� VC
layers
������� 9.3 ����Pxx layers
������� 9.4���� T12 layer
������� 9.5���� T01 layer
������� 9.6���� T02 layer
������� 9.7���� T21 layer
������� 9.8���� ETYn layer
������� 9.9���� ODU layer
������ 9.10���� OSC layer
������ 9.11���� FlexO layer
������ 9.12���� FlexE layer
10���� T12 section
layer functions
������ 10.1���� T12 connection
function T12_C
������ 10.2���� T12 trail
termination functions
11���� T01 section
layer functions
������ 11.1���� T01 connection
function T01_C
������ 11.2���� T01 trail termination
functions
12���� T02 section
layer functions
������ 12.1���� T02 connection
function T02_C
������ 12.2���� T02 trail
termination functions
13���� T21 section
layer functions
������ 13.1���� T21 connection
function T21_C
������ 13.2���� T21 trail termination functions
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 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 option II equipment
supporting second-generation SSM� and first-generation SSM using a translation
function
Appendix V� SDL descriptions
Appendix VI� Clarification of the use of the acronym
'SEC'
Appendix VII� Use cases of mixing SSM and eSSM