Recommendation ITU‑T G.8271/Y.1366 defines time and phase synchronization aspects in packet networks. It specifies the suitable methods to distribute the reference timing signals that can be used to recover the phase synchronization and/or time synchronization according to the required quality.

The requirements for the synchronization characteristics that are specified in this Recommendation must be adhered to in order to ensure interoperability of equipment produced by different manufacturers and a satisfactory network performance.

This 2017 edition of the Recommendation integrates G.8271/Y.1366 (2016) Amd.1 (2017) into the base text. It does not add any new technical content.

Amendment 1 provides the following update:

−           Addition to Appendix IV on network asymmetry.

Amendment 2 provides the following updates:

−           Added abbreviations and acronyms

−           Modified Tables 1 and 2

−           Enhanced description of FCS field in Annex A.1.3.2

−           Modified Table A.7

−           Added text to clause I.7.2

−           Modified Table II.1

−           Replaced Table II.2

−           Added references to the Bibliography