Recommendation ITU-T G.8275.1/Y.1369.1 contains the ITU-T precision time protocol (PTP) profile for phase and time distribution with full timing support from the network. It provides the necessary details to utilize [IEEE 1588] in a manner consistent with the architecture described in Recommendation [ITU‑T G.8275]. Amendment 1 incorporates the following updates: Clarifications on some dataset members use in the dataset comparison algorithm, Update PTSF functionality to include monitoring ports, Clarify the setting of the frequencyTraceable flag, Clarify defaultDS.deviceType, Add performance monitoring Annex F of [ITU‑T G.8275]. as an optional feature of this profile, Add clarification to Annex G and Annex K, Revised terminology based on inclusive language, Add new dataset members into Table A.1 and Table A.5, Add new profileVersion 2.6 and 2.7 in A.1 and A.11, Added Appendix XVI and XVII.