�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����
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
ITU-T G.8262/Y.1362����
Appendix I � Characteristics of Ethernet switches, Ethernet networks,
routers and access technologies����
������� I.1����
Characteristics of Ethernet switches and networks�������������
������� I.2����
Delay characteristics of routers�
������� I.3����
Delay characteristics of access technologies (Microwave nodes, PON, DSL)�������������
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�������
����� Page
����� VII.2����
Limits for the 1544 kbit/s interface�������
Appendix VIII � Synchronization status messaging in synchronous Ethernet
PHY����
Appendix IX � IWF examples����
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������
Appendix XIII � Evaluation of the packet delay variation generation in a
network node����
���� XIII.1����
Introduction�
���� XIII.2����
General considerations������������
��� XIII.3 �����General
configuration��������������
Bibliography����