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When NTP is marked as unmanaged service then sipXecs won't generate any configuration or issue any service start / stop commands. This is up to the admin, however some other system components (like phones) still need info about NTP configuration. That's why in addition to turning service in an unmanaged service, admin can also specify additional NTP servers phones or other components should default to.
The phone configuration will be automatically filled in with corresponding data
DNS
Managed service
Unmanaged service
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