Table of Contents - G.698.4 (05/2025) - Multichannel bi-directional DWDM applications with port agnostic single-channel optical interfaces

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	Classification of optical interfaces
	6.1	Applications
	6.2	Reference points
	6.3	Nomenclature
7	Transverse compatibility
8	Parameter definitions
	8.1	General information
	8.2	Interface at point SS or MPI-SM
	8.3	Optical path from point MPI-SM to RS or SS to MPI-RM
	8.4	Interface at point RS or MPI-RM
9	Parameter values
10	Optical safety considerations
11	Method of operation for 10 Gbit/s applications which do not have the ability to tune to the required TEE central frequency on its own but need feedback from the HEE
	11.1	Optical frequency setting during tuning
	11.2	Output power setting during tuning
12	Method of operation for remotely tuned 25 Gbit/s applications
	12.1	Introduction
	12.2	State machine for a remotely tuned TEE
13	Method of operation for self-tuning 25 Gbit/s applications
14	Method of operation for 25 Gbit/s applications which have remote performance monitoring ability
	14.1	Introduction
	14.2	Message channel clock recovery and frame detection
	14.3	Remote performance monitoring type of messages and data sets
	14.4	Remote performance monitoring state machines
Appendix I – Output power setting during tuning
Appendix II – Methods of operations used in this Recommendation
Appendix III – Example of RPM data exchange
Bibliography