D: Network Time Protocol (NTP)
D: Network Time Protocol (NTP)
As an option, Symmetricom can factory configure the XL-GPS to function as a Stratum 1
network time server. Network time servers use Network Time Protocol (NTP) to synchronize
computer clocks across a network. Alternatively, customers can upgrade a XL-GPS unit in
the field by purchasing the NTS option and installing a key to enable it.
Support for version 4.0 of the NTP, RFC 1305 as well as the Simple Network Time Protocol
(SNTP), RFC2030 is available. In addition, the XL-GPS responds to TIME protocol
requests, RFC868.
The Network Time Server responds to time synchronization requests from hosts using these
User Datagram Protocol/Internet Protocols (UDP/IP):
Type/Protocol
Port Number
RFC
NTP ver. 4.0:
UDP Port 123
RFC1305
SNTP:
UDP Port 123
RFC2030
TIME:
UDP Port 37
RFC868
NTP Packet Transmitted Timestamp Accuracy ±10 milliseconds.
Editing ntp.conf
Note: The XL-GPS is a Stratum 1 NTP server. Therefore, it does not support NTP peering,
in which a time server gets time information by sending an NTP query to another time
server. Entering valid IP addresses for the ‘server’ parameters (e.g., “
server
216.210.169.40
”) in ntp.conf does not enable peering in the XL-GPS.
The current text of “ntp.conf” is as follows:
# X L - G P S N T P . C O N F
# Load this version into the XL-GPS NTP Server for NTP MD5 and NTP
broadcast
#
# The line below to enables NTP broadcast mode using MD5 key 1.
broadcast 192.168.47.255 key 1
# Trust and accept NTP packets using MD5 keys 1 or 2.
# The MD5 keys and key ID specified in the XL-GPS's NTP.KEYS file must
match the
# same ones in the UNIX/Linux client NTP.KEYS file. The same keys for
both
# units must be specified as trusted by the line below.
trustedkey 1 2
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098-00116-000 Rev. A
Summary of Contents for XL-GPS
Page 1: ...XL GPS Time Frequency Receiver User Guide CD Part Number 098 00116 000 Rev A 5 May 2010 ...
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Page 214: ...IRIG IRIG Standard Format A 098 00116 000 Rev A Page 200 of 221 ...
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Page 216: ...F World Map of Time Zones 098 00116 000 Rev A Page 202 of 221 ...
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Page 220: ...I Certificate of Volatility See the following document 098 00116 000 Rev A Page 206 of 221 ...
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Page 225: ...J Declaration of Conformity See the following document 098 00116 000 Rev A Page 208 of 221 ...