Network Time Synchronization Servers at the U.S. Naval Observatory

Abstract

Responding to an increased demand for reliable, accurate time on the Internet and Milnet, the U.S. Naval Observatory Time Service has established the network time servers, tick.usno.navy.mil and tock.usno.navy.mil. The system clocks of these HP9000/747i industrial work stations are synchronized to within a few tens of microseconds of USNO Master Clock 2 using VMEbus IRIG-B interfaces. Redundant time code is available from a VMEbus GPS receiver. UTC(USNO) is provided over the network via a number of protocols, including the Network Time Protocol (NTP) [DARPA Network Working Group Report RFC-1305], the Daytime Protocol [RFC-867], and the Time protocol [HFC-868]. Access to USNO network time services is presently open and unrestricted. An overview of USNO time services and results of LAN and WAN time synchronization tests will be presented.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1994
Accession Number
ADA494738

Entities

People

  • R. E. Schmidt

Organizations

  • United States Naval Observatory

Tags

DTIC Thesaurus Topics

  • Atomic Clocks
  • Clocks
  • Frequency
  • Generators
  • Information Operations
  • Information Systems
  • Internet
  • Intervals
  • Ion Sources
  • Loran
  • Microsecond Time
  • Networks
  • Observatories
  • Operating Systems
  • Standards
  • Time Domain
  • Time Intervals

Fields of Study

  • Computer science

Readers

  • Computer Networking
  • Positioning, Navigation, and Timing (PNT) Technology.

Technology Areas

  • Space