�1���
�Scope�
�2��� �References�
�3��� �Definitions��
������ �3.1��� �Terms defined
elsewhere����
������ �3.2��� �Terms defined in this
Recommendation�������
�4��� �Abbreviations���
�5��� �Conventions�����
�6��� �General������
������ �6.1��� �Packet network
synchronization requirements���������
������ �6.2��� �TDM timing
requirements���
������ �6.3��� �Synchronization network
engineering in packet networks����
������ �6.4��� �Timing requirements at
edge versus timing requirements in core networks����
������ �6.5��� �PNT
domain and CES domain�������
�7��� �Reference
timing signal distribution over packet networks (PNT domain)��
������ �7.1��� �Plesiochronous and
network synchronous methods�
������ �7.2��� �Packet-based methods������
�8��� �Timing recovery for constant
bit rate services transported over packet networks (CES domain)��� �
������ �8.1��� �Network synchronous
operation����
������ �8.2��� �Differential methods�����������
������ �8.3��� �Adaptive methods��
������ �8.4��� �Reference clock
available at the TDM end systems�
�9��� �Network limits��
������ �9.1��� �CES network limits
������ �9.2��� �PNT network limits
10��� �Impact of impairments in the
packet network on timing distribution and service clock recovery��� �
����� �10.1��� �Packet transfer delay
and delay variation���
����� �10.2��� �Impacts from packet
impairments��
11��� �Impact of the reference clock
impairment on the service clock recovery���
����� �11.1��� �Impairments for the
network synchronous operation methods���������
����� �11.2��� �Impairments for the
differential method������
12��� �Results and consequences of the
different synchronization methods over packet network reference models��� �
����� �12.1��� �CES
domain recommendations�����
����� �12.2��� �PNT
domain recommendations�����
Annex A � Proposed network architecture for synchronous
Ethernet��� �
������ �A.1��� �PRC Location�������
������ �A.2��� �Limiting jitter and
wander of synchronous Ethernet�
������ �A.3��� �Considerations on the
design of synchronization network based on synchronous Ethernet��� �
������ �A.4��� �Example of timing
distribution via synchronous Ethernet������
������ �A.5��� �Interworking of Ethernet
and synchronous Ethernet interfaces���������
Annex B � IWF
functional partitioning into CES and PNT IWF and network examples��� �
������ �B.1��� �General��
������ �B.2��� �IWF clocks�����������
������ �B.3��� �Network examples
Annex C � CES
IWF synchronization related requirements��� �
������ �C.1��� �Traffic interfaces���
������ �C.2��� �Synchronization
interfaces�
������ �C.3��� �IWF synchronization
function��������
Annex D �
Network applications and requirements for clocks specified in G.8262/Y.1362��� �
Appendix I � Characteristics of Ethernet switches and networks���
�
������ �I.1��� ��� Delay
characteristics of Ethernet switches�
������ �I.2��� ��� Characteristics of
switched Ethernet networks������
Appendix II � Stabilization period��� �
Appendix III �
Considerations on packet-based methods��� �
Appendix IV � Applications and use cases��� �
����� �IV.1��� ��Background���������
����� �IV.2��� �Wireless
����� �IV.3��� �Infrastructure��������
����� �IV.4��� �Media gateway�����
Appendix V � Packet networks reference models��� �
������ �V.1��� �Ethernet networks
models�
������ �V.2��� �Other network models������
Appendix VI � Measurement guidelines for packet-based methods���
�
����� �VI.1��� �Measurement reference
points�������
����� �VI.2��� �Input traffic
characteristics�
����� �VI.3��� �Test topologies for
adaptive methods��������
����� �VI.4��� �Test Topologies for
differential methods����
����� �VI.5��� �Test for two-way
protocols�����������
Appendix VII � Wander limits in Deployment Case 1��� �
���� �VII.1��� �Limits for the 2048
kbit/s interface
���� �VII.2��� �Limits for the 1544
kbit/s interface
Appendix VIII � Synchronization status messaging in
synchronous Ethernet PHY��� �
Appendix IX � IWF examples��� �
���� �Page
Appendix X � Considerations on
measurement of synchronous Ethernet according to ITU-T methodologies in
comparison with IEEE jitter measurements��� �
Appendix XI �
Relationship between requirements contained in this Recommendation� and other
key synchronization related Recommendations��� �
Appendix XII �
Basic principles of timing over packet networks��� �
���� �XII.1��� �General�
���� �XII.2��� �Packet delay variation
mitigation by packet selection���������
���� �XII.3��� �Comparison of
packet-based and synchronous PHY methods�������
���� �XII.4��� �Existing standards�
Bibliography��� �