Table of Contents - G Suppl. 92 (10/2025) - Synchronization for data centres

1	Scope
2	References
3	Definitions
	3.1	Terms defined elsewhere
	3.2	Terms defined in this Supplement
4	Abbreviations and acronyms
5	Conventions
6	General
	6.1	Timing components in data centre end application
	6.2	Local vs distributed data centres
	6.3	Use cases for time synchronization in data centres
	6.4	Time error requirements
7	HRMs and synchronization network requirements
	7.1	HRMs for absolute time error requirements
	7.2	HRM for relative time error requirements
	7.3	Synchronization Network Requirements
8	Profiles
	8.1	PTP profiles for data centres synchronization
9	Clocks
10	Resiliency and security
11	Testing guidelines
	11.1	Standalone device testing
	11.2	 Network testing
	11.3	 Access to the TSC output
Appendix I – Basic concepts and application scenario examples
	I.1	AZ and region concept clarification
	I.2	Example of inter AZ time synchronization
	I.3	Example of intra AZ time synchronization
Appendix II – Industry-specific data centre applications and legacy systems
	II.1	Introduction
	II.2	Synchronization considerations for data centres in specific industry applications
	II.3	Data centres in Telecom
	II.4	Data centres in financial services