Recommendation ITU-T G.8273.2/Y.1368.2 specifies minimum requirements for time and phase for telecom boundary clocks and telecom time synchronous clocks used in synchronization network equipment that operates in the network architecture as defined in Recommendations ITU-T G.8271, ITU‑T G.8271.1, ITU-T G.8275 and ITU-T G.8275.1. It supports time and/or phase synchronization distribution for packet-based networks. This version of the Recommendation only applies to full timing support from the network. These requirements apply under the normal environmental conditions specified for the equipment. Amendment 2 provides the following updates: – Text clarification in Scope – References – Several text clarifications in clause 7. – Added noise tolerance for clock class D – Several updates in Clause 7.4 – Added Appendix XI – Added Appendix XII – Added Appendix XIII