User`s guide

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Up to 4 remote peers can be configured, all the peers are polled at intervals and the “best”
peer is selected for using as the time source.
SNTP should be configured prior to using NTP. The router will calculate the accuracy of the
NTP time servers over a period of time (up to 2 hours), once the drift compensation is
calculated the NTP client will be used.
The drift compensation value will be stored in NVRAM and written to the config.da0 file, if
the router looses power or is rebooted it will not need to re-calculate the accuracy of the
NTP servers again. The compensation value is constantly monitored to ensure it remains
correct.
Note:
If SNTP is used the accuracy of around 1 second is achieved.
If NTP is used 200 microsecond accuracy can be achieved.
Not all models support NTP – this option will only appear for models that do.
Initial Drift Compensation n ppm
NTP incorporates compensation for clock drift. If this parameter is known, it can be entered
here. Otherwise, the router will calculate this value over a period of time. Once calculated,
the value will be displayed in the text box.
Clock Precision Limit
Select the clock precision limit from the drop-down selection box.
Disable NTP when interface x,y is out of service
If the specified interface is out of service, the NTP is disabled until the interface is available
again.
NTP Servers 1 - 4
The router has the capability of configuring up to four NTP server connections. The more
servers that are used, the more accurate the time setting will be. The following section
describes the configuration of the connections.
NTP Server 1/2/3/4 Hostname
This field sets the NTP server hostname or IP address.
Broadcast Mode
When enabled, the NTP client will operate in a different manner. Rather than sending out an
NTP client message and expecting a reply, the NTP module will send out a broadcast mode
packet to the IP address configured in 'NTP host' field. The broadcast interval will be
determined by the value of 'Minimum poll interval'.
Poll Interval s1 to s2 seconds
These two parameters define the minimum and maximum intervals between poll
broadcasts. The values are time in seconds represented as a power of 2. This means that a
value of 4 means that the minimum poll interval is 2^4 = 16 seconds.
Startup burst Interval s seconds
When connecting to an NTP time server in polled mode, it may be necessary to send polls at
intervals shorter than the minimum poll interval in order to speed up the synchronization
process. This parameter controls the interval between polls during the startup process. This
feature is useful in situations where the router only has an intermittent Internet connection.