NTPRefId
NTPRefId is an octet string that indicates the reference clock identifier. In the case of stratum 0 (unspecified) or stratum 1 (primary reference source), this is a four-octet, left-justified, zero-padded ASCII string as defined in RFC-1305. In the case of stratum 2 and greater (secondary reference) this is the four-octet Internet address of the peer selected for synchronization. Some examples of stratum 0 identifiers are, DCN, DCN routing protocol NIST, NIST public modem TSP, TSP time protocol DTS, Digital Time Service Some examples of stratum 1 identifiers are, ATOM, Atomic clock (calibrated) VLF, VLF radio (OMEGA,, etc.) LORC, LORAN-C radionavigation GOES, GOES UHF environment satellite GPS, GPS UHF satellite positioning