The Calnex G.8271.2 APTS and PTS Tolerance Noise Patterns meet the specifications in G.8273.4 Appendix VI clauses VI.4.1 and VI.4.2 respectively. The pattern files are at the bottom of this page.
ITU-T G.8271.2 (05/2021) defines the maximum permissible levels of phase/time error for a network enabling the synchronisation of Class 4 (±1.5μs) applications. Reference Point C is the output of the partial timing support packet network and the input into the last APTS or PTS device in the timing chain.
G.8273.4 Amd1 (05/2021) defines the maximum noise a device must tolerate while delivering within specification timing. There are different noise tolerance requirements for APTS and PTS devices as, although the network reference point is the same, part of the capability of an APTS clock is to compensate for cTE generated by the network therefore a large asymmetry is added. The differences are described in G.8273.4 Appendix VI.4.