�1���� Scope��������
�2���� References�������������
�3���� Definitions
������� 3.1���� Terms defined elsewhere������
������� 3.2���� Terms defined in this Recommendation����������
�4���� Abbreviations���������
�5���� Conventions�����������
������� 5.1���� Representation of octets��������
�6���� Introduction�����������
�7���� Ring protection characteristics��������
������� 7.1���� Monitoring methods and conditions���
������� 7.2���� Ethernet traffic and bandwidth consideration�
������� 7.3���� Ethernet ring protection switching performance���������
�8���� Ring protection conditions and commands��
�9���� Ring protection architectures����������
������� 9.1���� Revertive and non-revertive switching������������
������� 9.2���� Protection switching triggers�
������� 9.3���� Protection switching models on a single Ethernet ring
������� 9.4���� Traffic channel blocking��������
������� 9.5���� R-APS channel blocking����������
������� 9.6���� FDB flush������
������� 9.7���� Ethernet ring protection switching models for interconnection
10���� Protection control protocol�������������
������ 10.1���� Principles of operations��������
������ 10.2 ����Protection switching behaviour���������
������ 10.3���� R-APS format�����������
������ 10.4���� Failure of protocol defect�����
Appendix I � Ring protection network objectives����
Appendix II � Ethernet ring network objectives����
Appendix III � Ring protection scenarios ����
Appendix IV � Considerations for the different timers����
������ IV.1���� State machine use of timers��
������ IV.2���� Guard timer use to block outdated R-APS messages����
Appendix V � Interconnected rings example����
������� V.1���� Configuration for interconnected rings�����������
������� V.2���� Topology examples for interconnected Ethernet rings
Appendix VI � Protection switching for multiple ERP instances����
������ VI.1���� Multiple ERP instances����������
������ VI.2���� Applying protection mechanisms to multiple ERP instances�����
������ VI.3���� Protection switching model for multiple ERP instances������������
������ VI.4���� Multiple instances of interconnected rings�����
Appendix VII � Guidelines for the configuration of VIDs and Ring-IDs of R-APS
channels����
����� VII.1���� Sub-ring with R-APS virtual channel���
����� VII.2���� Example 3: Sub-ring without R-APS virtual channel model; each
R-APS channel with different VIDs����
����� VII.3���� Example 4: Co-existence on an Ethernet ring of Ethernet ring
nodes which support this Recommendation (v2) and the previous version (v1) of
this Recommendation����
Appendix VIII � Flush optimization����
���� VIII.1���� Flushing FDB consideration���
���� VIII.2���� Scenarios of unnecessary FDB flushing������������
���� VIII.3���� Example of FDB flush optimization�����
���� VIII.4���� Additional definition for ERP control process model and state
machine�������������
���� VIII.5���� DNF status���
Appendix IX � Guidelines for management procedures����
������ IX.1���� An example procedure for removing an Ethernet ring node�����
������ IX.2���� Management procedures to exit the FS state in case of failure
of an Ethernet ring node under an FS condition����
������ IX.3���� Replacing a v1 Ethernet ring node with a v2 Ethernet ring node�����������
Appendix X � Minimizing segmentation in interconnected rings����
������� X.1���� Characterization of the segmentation issue����
������� X.2���� Class of double faults addressed���������
������� X.3���� Procedure for minimization of segmentation��
Appendix XI � End-to-end service resilience����
������ XI.1���� Generic end-to-end service resilience
������ XI.2���� Layering ITU-T G.8031 protection over ITU-T G.8032���
������ XI.3���� End-to-end service that traverses interconnected rings������������
Bibliography����