Recommendation ITU-T G.8275.2/Y.1369.2 Amendment 3 (02/2022) Precision time protocol telecom profile for phase/time synchronization with partial timing support from the network
Summary
History
FOREWORD
Table of Contents
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 Use of PTP for phase/time distribution
     6.1 High-level design requirements
     6.2 PTP modes and options
          6.2.1 PTP Domains
          6.2.2 PTP messages
          6.2.3 Types of PTP clocks supported in the profile
     6.3 PTP modes
          6.3.1 One-way versus two-way operation
          6.3.2 One-step versus two-step clock mode
          6.3.3 Unicast versus multicast mode
     6.4 PTP mapping
     6.5 Message rates
     6.6 Unicast message negotiation
     6.7 Alternate BMCA, telecom slave model and master selection process
          6.7.1 Alternate BMCA
          6.7.2 Considerations on the use of the localPriority attributes
          6.7.3 Static clock attribute priority1
          6.7.4 Clock attribute priority2
          6.7.5 Clock attribute clockClass
          6.7.6 Clock attribute clockAccuracy
          6.7.7 Clock attribute offsetScaledLogVariance
          6.7.8 State decision algorithm
          6.7.9 Data set comparison algorithm
          6.7.10 Unused PTP fields
          6.7.11 Packet timing signal fail
     6.8 Phase/time traceability information
     6.9 Use of alternate master flag
7 ITU-T PTP profile for phase/time distribution with partial timing support from the network
8 Security aspects
Annex A  ITU-T PTP profile for time distribution with partial timing support  from the network (unicast mode)
     A.1 Profile identification
     A.2 PTP attribute values
     A.3 PTP options
          A.3.1 Node types required, permitted or prohibited
          A.3.2 Transport mechanisms required, permitted, or prohibited
          A.3.3 Unicast messages
          A.3.4 REQUEST_UNICAST_TRANSMISSION TLV
          A.3.5 GRANT_UNICAST_TRANSMISSION TLV
     A.4 Best master clock algorithm options
     A.5 Path delay measurement option (delay request/delay response)
     A.6 Configuration management options
     A.7 Clock identity format
     A.8 Security aspects
     A.9 Other optional features of IEEE 1588
     A.10 PTP common header flags
Annex B  Options to establish the PTP topology with the Alternate BMCA
Annex C  Inclusion of an external phase/time input interface on a PTP clock
Annex D  TLV for PTP interface rate (optional)
Annex E   Synchronization uncertain indication (optional)
Annex F  Mapping from PTP clockClass values to quality levels
Appendix I  Considerations on the use of priority2
Appendix II  Considerations on a T-TSC-A or T-TSC-P connected to an end application
Appendix III  PTP monitoring backup scenario example
Appendix IV  Description of PTP clock modes and associated contents of Announce messages
Appendix V  BMCA cycling between masters
     V.1 Scenario where a PTP clock's BMCA cycles between two masters
     V.2 Approaches to avoid a PTP clock's BMCA from cycling between two masters
          V.2.1 Requesting Sync and/or Delay_Resp service for non-selected masters
          V.2.2 Disqualify master triggering PTSF lossSync alarm
Appendix VI  Considerations of PTP over IP transport in ring topologies
Appendix VII  Considerations on the configuration of PTSF-lossSync
Appendix VIII  Operations over link aggregation
     VIII.1 Functional model
     VIII.2 Scenario
Appendix IX  Considerations on the use of [IEEE 1588-2019]
Appendix X  Considerations on selecting time out values
     X.1 Example receipt timeout calculation (Dynamic message rate)
     X.2 Example receipt timeout calculation (Fixed message rate)
     X.3 Range of receipt timeout
Bibliography
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