Date and Time
The PBX requires a system time. The available time information is a prerequisite for functions such as automatic configuration switching but also encrypted telephony.
The PBX has the following features for this purpose
an internal clock
a buffered real-time clock that stores the time for approx. two hours in the case of a power outage (only COMtrexx Business or COMtrexx Flex)
The PBX time can be updated as follows:
Set time manually
Set time by taking over from the PC
Set time automatically by querying the entered NTP servers
The associated telephones/devices usually also require mandatory time. For this purpose, the PBX provides one of the following NTP servers in the devices:
PBX as NTP server (devices in the same network are then supplied with the system time)
entered NTP server
Default NTP pool
*Important: If the units are neither in the network of the PBX nor are they able to reach addresses on the Internet, an individually created provisioning file is required in which an accessible NTP server is entered.
*For more information on data exchange with public NTP servers, take a look at the Privacy Policy of the COMtrexx. You will find this in the Internet under: Auerswald Support/FONtevo Support or here: Dashboard > Status information > Legal > Data protection
Configuration 
Configuring PBX time.
Administration > Date and Time
Providing the PBX as NTP server.
Administration > Date and Time > Automatic distribution