Table of Contents - G.8013/Y.1731 (2023) Amd. 1 (05/2025) -

1	Scope
2	References
3	Definitions
	3.1	Terms defined elsewhere
	3.2	Terms defined in this Recommendation
4	Abbreviations and acronyms
5	Conventions
	5.1	ME group (MEG)
	5.2	Traffic conditioning point (TrCP)
	5.3	MEG level
	5.4	OAM transparency
	5.5	Representation of octets
6	OAM relationships
	6.1	MEs, MEPs, MIPs and TrCPs relationship
	6.2	MEs, MEGs and MEG level relationship
	6.3	MEPs and MIPs configuration
7	OAM functions for fault management
	7.1	Ethernet continuity check (ETH-CC)
	7.2	Ethernet loopback (ETH-LB)
	7.3	Ethernet link trace (ETH-LT)
	7.4	Ethernet alarm indication signal (ETH-AIS)
	7.5	Ethernet remote defect indication (ETH-RDI)
	7.6	Ethernet locked signal (ETH-LCK)
	7.7	Ethernet test signal (ETH-Test)
	7.8	Ethernet automatic protection switching (ETH-APS)
	7.9	Ethernet management communication channel (ETH-MCC)
	7.10	Ethernet experimental OAM (ETH-EXP)
	7.11	Ethernet vendor-specific OAM (ETH-VSP)
	7.12	Ethernet client signal fail (ETH-CSF)
	7.13	Ethernet bandwidth notification (ETH-BN)
	7.14	Ethernet expected defect (ETH-ED)
8	OAM functions for performance monitoring
	8.1	Ethernet frame loss measurement (ETH-LM)
	8.2	Ethernet frame delay measurement (ETH-DM)
	8.3	Throughput measurement
	8.4	Ethernet synthetic loss measurement (ETH-SLM)
	Page
9	OAM PDU types
	9.1	Common OAM information elements
	9.2	CCM PDU
	9.3	LBM PDU
	9.4	LBR PDU
	9.5	LTM PDU
	9.6	LTR PDU
	9.7	AIS PDU
	9.8	LCK PDU
	9.9	TST PDU
	9.10	APS PDU
	9.11	MCC PDU
	9.12	LMM PDU
	9.13	LMR PDU
	9.14	1DM PDU
	9.15	DMM PDU
	9.16	DMR PDU
	9.17	EXM PDU
	9.18	EXR PDU
	9.19	VSM PDU
	9.20	VSR PDU
	9.21	CSF PDU
	9.22	SLM PDU
	9.23	SLR PDU
	9.24	1SL PDU
	9.25	BNM PDU
	9.26	EDM PDU
10	OAM frame addresses
	10.1	Multicast destination addresses
	10.2	CCM
	10.3	LBM
	10.4	LBR
	10.5	LTM
	10.6	LTR
	10.7	AIS
	10.8	LCK
	10.9	TST
	10.10	APS
	10.11	MCC
	Page
	10.12	LMM
	10.13	LMR
	10.14	1DM
	10.15	DMM
	10.16	DMR
	10.17	EXM
	10.18	EXR
	10.19	VSM
	10.20	VSR
	10.21	CSF
	10.22	SLM
	10.23	SLR
	10.24	1SL
	10.25	BNM
	10.26	EDM
11	OAM PDU validation and versioning
	11.1	OAM PDU transmission
	11.2	OAM PDU validation in reception
	11.3	OAM PDU reception after validation
Annex A – MEG ID format
	A.1	ICC-based MEG_ID format
	A.2	Global MEG ID format based on CC and ICC
Annex B – Ethernet link trace (ETH-LT) of ITU-T Y.1731 interoperability considerations
	B.1	Ethernet link trace (ETH-LT) as specified in ITU-T Y.1731
	B.2	Interworking with ITU-T Y.1731
Appendix I – Ethernet network scenarios
	I.1	Shared MEG levels example
	I.2	Independent MEG levels example
Appendix II – Frame loss measurement
	II.1	Simplified calculation for frame loss
	II.2	Frame counter wrapping periodicity
Appendix III – Network OAM interworking
Appendix IV – Mismerge detection limitation
Appendix V – Terminology alignment with IEEE 802.1Q
Appendix VI – Examples showing accuracy for ETH-SLM measurement
Appendix VII – ETH-LM and link aggregation
Bibliography