Digi Connect WAN Series User Manual page 122

Digi Connect WAN Family web interface
The Time Adjustment Threshold value can range from 0 to 300 seconds. For example, if the
configured threshold is 60 seconds, the Digi device's time will be updated using a new time
value that is 60 seconds or more different than the Digi device's current time value. If the new
time value differs from the Digi device's current time by less than 60 seconds, the Digi device's
time is not updated using that new time.
Enable Lost Time Source Recovery: If multiple external time sources are available and
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configured in the Time Source Settings, normally only the best-ranking (smallest value) source
(s) will be used to maintain the Digi device's time. If the best-ranking source stops reporting
new time values, it is considered "lost".
Enabling Lost Time Source Recovery allows the Digi device to consult one or more worse-
ranking (higher value) time sources in an effort to obtain a fresh time value. This prevents the
best-ranking configured time source from blocking time updates if that source stops providing
acceptable time samples.
The interval of time that must pass for Lost Time Source Recovery to begin varies according to
the best ranking time source that is reporting a value. For a time source of type "sntp server",
the missing sample update interval is three NTP/SNTP intervals configured for that time
source, plus one minute. For a time source other than "sntp server", the missing sample
update interval is 61 minutes. You cannot configure these interval values.
Use the Time Adjustment Threshold to limit the amount of drift that will be tolerated before the Digi
device's time is updated using a new sample. You should select an appropriate value with
consideration for the reliability of the time sample sources.
In the case of NTP/SNTP server sources, you should also consider the latency, round-trip timing, and
reliability of the network connection (between the Digi device and the server).
If the communications path between the Digi device and server involves a cellular network
connection, you should consider the performance and behavior characteristics of the cellular network.
In a cellular network, intermittent packet delays are possible in either the transmit or receive
direction (or both). Frequently these delays are asymmetric, such that the delay is greater in one
direction than in the other.
In such conditions, the round-trip timing (of the request/reply) skews the time sample adjustment to
determine the time value to use for the device. Therefore configuring an aggressively small (short)
threshold value may cause the device to adjust its time frequently and unnecessarily, such that the
time value "jumps" forward or backward as a consequence of asymmetric packet delays.
Remote Manager settings
The Remote Manager configuration page sets up the connection to the Device Management remote
management server so the Digi device can connect to the server. Device Management allows you to
configure and manage Remote Manager-registered devices from remote locations.
In this discussion:
Remote Manager refers to the Digi machine-to-machine cloud-based network operating
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platform.
Device Management refers to a web based device management application that allows a user
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to manage their inventory of devices.
Digi Connect WAN Family User Guide
Configuration through the web interface
122