Amendment 1 to Recommendation ITU-T G.8275.1 (2016/06) provides the following updates: - Added G.8271 to references - Addition of a new definition: Special Port (3.2) - Clarification on the use of logMessageInterval in Delay_Resp messages (6.2.8) - Clarification on the behaviour of the T-BC Announce message contents when the T-BC has a parent clock. - Incremented the minor revision number of the profileVersion (Annex A) - Correction to the handling of the alternateMasterFlag - Added informative text on the handling of the synchronizationUncertain flag (Annex E) - Added monitoring of a PTP MASTER port by a PTP PASSIVE port (Annex G) - Updates to Announce message fields of currentUtcOffset and synchronizationUncertain when using PTP clock states (Appendix V) - Update of Appendix VII - Added informative use cases for the use of the priority2 attribute (Appendix X) - Added considerations on native access equipment (Appendix XI) - Added monitoring alternate master time information provided by a peer PTP port (Appendix XII)