Summary - G.781.1 (05/2025) - Synchronization layer functions for packet-based synchronization

Recommendation ITU-T G.781.1 specifies a functional architecture model and corresponding atomic functions for the transport of time and frequency synchronization via packet-based methods using the precision time protocol (PTP).
This revision of Recommendation ITU-T G.781.1 provides the following updates:
•Revised terminology based on inclusive language
•Updated Figure 6-1 "The high-level functional architecture for transport of packet-based synchronization via PTP over transport layers"
•Updated Figure 8-11 "Clock mode state transitions", the definitions of the modes and Table 810 "Transition information"
•Updated clause 9.2 "OTUk to SD-p adaptation functions"
•Corrected OTSn to OSC in clause 9.3
•Added clause 9.4 "FlexE to SD-p adaptation functions"
•Added clause 9.6 "MTNSy to SD time sync adaptation functions".
Added details in Appendix III "Analysis of message delay times for NEs in packet-based synchronization networks".