Table of Contents - G.8275 (01/2026) - Common aspects of PTP profiles for phase/time synchronization

1	Scope
2	References
3	Definitions
4	Abbreviations and acronyms
5	Conventions
6	General introduction of phase and time profiles
7	Security aspects
Annex A – Time/phase models based on [ITUT G.805]
Annex B – Inclusion of a virtual PTP port on a PTP clock
Annex C – Options to establish the PTP topology with the alternate BTCA
Annex D – Synchronization uncertain indication (optional)
Annex E – Use of the timeTransmitterOnly and notTimeTransmitter  parameters in networks
	E.1	Use of timeTransmitterOnly
	E.2	Use of notTimeTransmitter
Annex F – Performance monitoring (optional)
	F.1	Data storage
	F.2	Use cases when local PTP clock is not used for timestamping
	F.3	Considerations for [ITUT G.8275.2]
	F.4	Time reference information per PTP instance
	F.5	Time reference information per PTP port
	F.6	Additional parameters
Annex G – Synchronization service availability performance metrics (optional)
	G.1	Service availability performance metrics implementation at the node
	G.2	Example of possible PM handling in the NMS
	G.3	Dataset definition
Appendix I – Architecture for time and phase distribution over a packet network  providing PTS at the protocol level
Appendix II – An example of PRTC switching by the BTCA in a ring network
Appendix III – Generic IWF node
	III.1	Introduction
	III.2	Interworking between the [ITUT G.8275.1] and [ITUT G.8275.2] profiles
	III.3	Generation of the physical layer frequency signal by the IWF
	III.4	Mapping IWF to telecom PTP clocks
Appendix IV – Use cases for mapping from PTP clockClass values to quality levels
	IV.1	Use case I
	Page
	IV.2	Use case II
Appendix V – Deployment examples and the use of partially aware deviceTypes
Appendix VI – cnPRTC functional architecture
Appendix VII – cnPRTC deployment scenarios
Appendix VIII – Description of PTP clock modes and associated contents of Announce messages
	VIII.1	Purpose of this appendix
	VIII.2	Description of the modes
	VIII.3	Example of mapping between PTP port states and PTP clock modes for a 3-port TBC/ TBCP/ TBCA
	VIII.4	TGM Announce message contents based on the internal PTP clock modes
	VIII.5	TBC/ TBCP/ TBCA Announce message contents based on the internal PTP clock modes
Appendix IX – Considerations on the use of [IEEE 15882019]
Appendix X – Flexible synchronization network based on cnPRTC
Appendix XI – Information that can be used in the analysis of the performance monitoring data
Appendix XII – Updated terminology for PTP clocks and PTP profiles
Appendix XIII – Considerations on PTP Security
	XIII.1	Options for protecting PTP
	XIII.2	Combinations of security mechanisms
Appendix XIV – Calculation of offsetScaledLogVariance for TGM timed by PRTC or ePRTC
	XIV.1	Observation interval and TDEV noise generation
	XIV.2	Computation of PTP variance from TDEV
	XIV.3	Computation of offsetScaledLogVariance from PTP variance
	XIV.4	Numeric application to PRTC-A, PRTC-B and ePRTC
Appendix XV – Considerations of deploying ePRTCs and PRTCs in the network
Appendix XVI – Considerations on timer reconfiguration
Bibliography