Zenitel Marine Master Clock 70000, Technical User'S Manual

Page: 77 / 118

Document: DOK11086en01
Author: PM
Date: 2021-06-16
Page: 12 of 2
2
WESTERSTRAND
Trap type
This function is used to choose SNMP trap
version. Trap type v1 = Trap according to
SNMPv1
Trap type v2 = Trap according to SNMPv2
NTP
NTP settings
General description
Westerstrand NTP Servers has several features to achieve a reliable and accurate time service. The
configuration of the different facilities is flexible, and the features can be selected or deselected
depending on each customer’s individual needs.
The Server can work as NTP Server only or as both NTP Server and NTP Client.
When working as NTP Client the unit has three different ways to determine the most accurate
and reliable candidates to synchronize the system clock. Which model that is used depends on the
specific installation and the customer requirements. The NTP client has also a server list where
up to 5 different time servers can be entered.
The three different ways are:
1.
FIRST Always use the first server in the list if available. If not available, take next one.
This suits installations where it is more important to know exactly from where the clients get time
than to have the most accurate time. The other NTP servers in the list will then be more of backup
servers.
2.
STRATUM Use the NTP server with best stratum. The software sends a request to all servers in
the list and uses the time from the one with best stratum. If same stratum it will use the one that is
first in the server list. This suits installations where it is important that the time is coming from a
time server high up in the pyramid.
3.
MEDIAN Send a request to all servers in the list and use the median value (the NTP server
that is in the middle). This will filter out all misleading time messages.
In addition to these rules there are some more features such as synchronization limits and a special
clock adjusting algorithm where the speed of internal oscillator is increased or decreased depending
on the difference between the internal clock and the NTP message. All of this to avoid false and
inaccurate time and to give a, when needed, smooth time adjustment without time jumps.
A clock discipline algorithm is also included. This algorithm measures the oscillators drift over a
longer period and makes compensations for the drift.
WESTERSTRAND URFABRIK AB
P.O. Box 133 Tel. +46 506 48000 Internet: http://www.westerstrand.se
SE-545 23 TÖREBODA Fax. +46 506 48051 E-mail: info@westerstrand.se