Table of Contents for NTP software

The NTP Software and Document

This directory and its subdirectories contain the various distribution of the Network Time Protocol (NTP), together with related auxilliary programs, documentation and strange stuff. You are welcome to the lot, with due consideration of the COPYRIGHT files stashed in the distributions. You are also invited to contribute bugfixes and drivers for new and exotic radios, telephones and sundials.

For anonymous FTP retrieval, the base directory pub/ntp contains the distributions and related stuff, including:

bsd_audio.tar.Z

Compressed tar archive containing the bsd audio driver for Sun workstations modified to include support for IRIG-B signals generated by some radio timecode receivers. Compatible with the xntp3.tar.Z distribution.

gadget.tar.Z

Compressed tar archive containing the schematics, artwork and related information for (a) a modem for the Canadian time/frequency radio service CHU, which can be used as a primary reference clock for NTP Version 2 and Version 3 daemons, and (b) a pulse shaper and line driver used to provide an external one-pulse-per-second signal from a radio clock to a serial port.

icom.tar.gz

Compressed tar archive containing a program to control HF/VHF radios made by the ICOM Corporation. It can be used interactively or run from a shell script to adjust the frequency, mode and related parameters of one or more radios connected to the CI-V local network. It can also be used in conjunction with the minimuf.tar.Z distribution to automatically tune radios as propagation conditions change throughout the seasons and hours.

kernel.tar.Z

Compressed tar archive containing a report and sample programs for Unix kernel changes to implement a precision, disciplined clock.

loran.tar.Z

Compressed tar archive containing the schematics, artwork and documentation for a computer-controlled LORAN-C timing receiver used as a precision source of standard time. Not recommended for beginners.

minimuf.tar.Z

Compressed tar archive containing a program that computes high frequency radio propagation data and delays between two geographic locations on the Earth. This is intended for use in setting propagation-delay switches on radio clocks. It can be used with the icom.tar.Z distribtution to automatically tune radios as propagation conditions change throughout the seasons and hours.

msctime.tar.Z

Compressed tar archive containing the NIST Automated Computer Time Service software, ported to Microsoft C for IBM PC and Unix C for Sun workstations

nbstime.tar.Z

Compressed tar archive containing the NIST Automated Computer Time Service software, as distributed by NIST.

ntpdate_vms.tar.Z

Compressed tar archive containing a version of the ntpdate utility program for the VMS operating system.

Compressed tar archive containing the NTP Version 3 daemon for Unix adapted from the version-3 daemon by Lars Mathiesen of the University of Copenhagen and many of his friends. Unrestricted distribution. Requires a software implementation of the Data Encryption Standard readily available outside the U.S. and Canada.

The doc subdirectory includes a number of compressed files containing papers, rfcs and technical reports on NTP and related topics. Those with names ending in *.ps.Z are in PostScript, while the others are in ASCII. When the same document is displayed with *.ps.Z and *.txt.Z extension, the latter version is an ASCII-greppable file that may not violate the Principle of Least Astonishment with respect to the former version; however, much is lost in translation.

accuracy.ps.Z, accuracy.txt.Z

Compressed PostScript and ASCII files for a paper on practice and experience operating NTP in the global Internet

Mills, D.L. ``On the accuracy and stability of clocks synchronized by the Network Time Protocol in the Internet system.'' ACM Computer Communication Review 20, 1 (January 1990), 65-75.

algorithm.ps.Z

Mills, D.L. ``Improved algorithms for synchronizing computer network clocks.'' Proc. ACM SIGCOMM 94 Symposium (London UK, September 1994), 317-327.

clock.txt

ASCII file containing (a) a list of primary (stratum 1) servers operating in the Internet, (b) a list of secondary (stratum 2) servers operating in the Internet, (c) a list of known radio timecode receivers along with addresses and phone numbers of the suppliers, (d) bits of riffraff information that defy classification. This file is updated on a haphazard basis at irregular intervals.

dts1.txt.Z, dts2.txt.Z

Compressed ASCII files containing unpublished message digests comparing NTP and the Digital Time Synchronization Service (DTSS). Note: this is an informal discussion and should not be quoted or excerpted, even with attribution.

dts3.ps.Z, dts3.txt.Z

Compressed PostScript and ASCII files for an unpublished technical memorandum comparing NTP and the Digital Time Synchronization Service (DTSS). Note: this memorandum is intended for professional use only and should not be cited or excerpted without the consent of the author.

faq.Z

Compressed ASCII file containing frequently asked questions about NTP, its installation, configuration and management. Refreshed at irregular intervals.

info1.txt.Z, info2.txt.Z

Compressed ASCII files containing useful hints and kinks on setting up NTP service

jaguar.txt.Z

Compressed ASCII file containing a job description for a Maya high priest taken from the Book of Chillum Balum. Useful for after-dinner speakers and rally cheerleaders.

rfc1119.ps.Z, rfc1119.txt.Z

Compressed PostScript and ASCII files for the NTP Version 2 specification. Of historic interest.

Mills, D.L. ``Network Time Protocol (Version 2) specification and implementation.'' DARPA Network Working Group Report RFC-1119, University of Delaware, September 1989. Also published as: Electrical Engineering Department Report 89-9-2, University of Delaware, September 1989.

rfc1128.ps.Z, rfc1128.txt.Z

Compressed PostScript and ASCII files for rfc1128 available from Internet archive sites.

Mills, D.L. ``Measured performance of the Network Time Protocol in the Internet system.'' DARPA Network Working Group Report RFC-1128, University of Delaware, October 1989. Also published as: Electrical Engineering Department Report 89-9-3, University of Delaware, September 1989.

rfc1129.ps.Z, rfc1129.txt.Z

Compressed PostScript and ASCII files for rfc1129 available from Internet archive sites.

Mills, D.L. ``Internet time synchronization: the Network Time Protocol.'' DARPA Network Working Group Report RFC-1129, University of Delaware, October 1989. Also published as: Electrical Engineering Department Report 89-9-1, University of Delaware, September 1989.

rfc1305.tar.Z

Compressed tar archive for rfc1305 available from Internet archive sites

rfc1305a.ps.Z, rfc1305b.ps.Z, rfc1305c.ps.Z

Compressed PostScript and ASCII files for rfc1305 available from Internet archive sites.

Mills, D.L. ``Network Time Protocol (Version 3) specification, implementation and analysis.'' DARPA Network Working Group Report RFC-1305, University of Delaware, March 1992, 113 pp. Previous draft published as: Electrical Engineering Department Report 90-6-1, University of Delaware, June 1990.

rfc1361.txt.Z

Compressed ASCII file for rfc1361 available from Internet archive sites.

Mills, D.L. ``Simple Network Time Protocol (SNTP).'' DARPA Network Working Group Report RFC-1361, University of Delaware, August 1992, 10 pp.

rfc1589.txt.Z

Compressed ASCII file for rfc1589 available from Internet archive sites.

Mills, D.L. ``A kernel model for precision timekeeping.'' ARPA Network Working Group Report RFC-1589, University of Delaware, March 1994. 31 pp.

sntp.txt.Z

Compressed ASCII file for a revision and update of rfc1361 submitted to the RFC Editor.

Mills, D.L. ``Simple Network Time Protocol (SNTP).'' DARPA Network Working Group Report RFC-XXXX, University of Delaware, September 1994, 12 pp.

security.ps.Z

Compressed PostScript file containing a draft of a report by Matt Bishop discussing security issues in NTP. It should not be cited or excerpted without the permission of the author.

time.ps.Z, time.txt.Z

Compressed PostScript and ASCII files for a paper discussing issues in timescales, calendrics and associated mythology.

Mills, D.L. ``On the chronology and metrology of computer network timescales and their application to the Network Time Protocol.'' ACM Computer Communications Review 21, 5 (October 1991), 8-17.

wiretap.ps.Z

Compressed PostScript file for a paper on routing in packet-radio networks. Off the wall, but whattheheck.

Mills, D.L. Wiretap: an experimental multiple-path routing algorithm. ACM Computer Communication Review 19, 1 (January 1989), 85-98.

The depredated directory contains previous versions of the NTP protocol implementations. There use is strongly discouraged in new installations. There is no guarantee that these versions will be supported in future.

Last modified: Jan. 17, 2001