RFC 1769 (rfc1769) - Page 1 of 14
Simple Network Time Protocol (SNTP)
Alternative Format: Original Text Document
Network Working Group D. Mills
Request for Comments: 1769 University of Delaware
Obsoletes: 1361 March 1995
Category: Informational
Simple Network Time Protocol (SNTP)
Status of this Memo
This memo provides information for the Internet community. This memo
does not specify an Internet standard of any kind. Distribution of
this memo is unlimited.
Abstract
This memorandum describes the Simple Network Time Protocol (SNTP),
which is an adaptation of the Network Time Protocol (NTP) used to
synchronize computer clocks in the Internet. SNTP can be used when
the ultimate performance of the full NTP implementation described in
RFC-1305 is not needed or justified. It can operate in both unicast
modes (point to point) and broadcast modes (point to multipoint). It
can also operate in IP multicast mode where this service is
available. SNTP involves no change to the current or previous NTP
specification versions or known implementations, but rather a
clarification of certain design features of NTP which allow operation
in a simple, stateless remote-procedure call (RPC) mode with accuracy
and reliability expectations similar to the UDP/TIME protocol
described in RFC-868.
This memorandum obsoletes RFC-1361 of the same title. Its purpose is
to explain the protocol model for operation in broadcast mode, to
provide additional clarification in some places and to correct a few
typographical errors. A working knowledge of the NTP Version 3
specification RFC-1305 is not required for an implementation of SNTP.
Distribution of this memorandum is unlimited.
1. Introduction
The Network Time Protocol (NTP) specified in RFC-1305 [MIL92] is used
to synchronize computer clocks in the global Internet. It provides
comprehensive mechanisms to access national time and frequency
dissemination services, organize the time-synchronization subnet and
adjust the local clock in each participating subnet peer. In most
places of the Internet of today, NTP provides accuracies of 1-50 ms,
depending on the characteristics of the synchronization source and
network paths.
Mills
