Network Time Protocol (version 1) specification and implementation, July 1988
- Canonical URL:
- File formats:
- RFC 958
- Obsoleted by:
- RFC 1119, RFC 1305
- D.L. Mills
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This memo describes the Network Time Protocol (NTP), specifies its formal structure and summarizes information useful for its implementation. NTP provides the mechanisms to synchronize time and coordinate time distribution in a large, diverse internet operating at rates from mundane to lightwave. It uses a returnable-time design in which a distributed subnet of time servers operating in a self- organizing, hierarchical master-slave configuration synchronizes logical clocks within the subnet and to national time standards via wire or radio. The servers can also redistribute reference time via local routing algorithms and time daemons. The NTP architectures, algorithms and protocols which have evolved over several years of implementation and refinement are described in this document. The prototype system, which has been in regular operation in the Internet for the last two years, is described in an Appendix along with performance data which shows that timekeeping accuracy throughout most portions of the Internet can be ordinarily maintained to within a few tens of milliseconds, even the cases of failure or disruption of clocks, time servers or nets. This is a Draft Standard for an Elective protocol.
For the definition of Status, see RFC 2026.
For the definition of Stream, see RFC 4844.