ABSTRACT
UNIX supports the distribution of an accurate time throughout the network. This means that each host in the overall network is synchronized to a selected timeserver, or servers, which transmit a reference clock time to the time client hosts. A reference clock will generally (though not always) be a radio time code receiver that is synchronized to a source of standard time such as NIST in the U.S., or NRC in Canada. The time distribution is based on the network time protocol (NTP), currently version 4 which is fully compliant with version 3 standard, defined by Request for Comments RFC 1305, and compatible with previous versions 2 and 1, defined by RFC 1119 and RFC 1059. The computation done in the protocol is fully provided in fixed-point arithmetic, and together with the clock adjustment code, brings a high precision that maintains accuracy comparable with even the most precise external time sources.
