If you just leave the OBi at its default settings, and not change anything whatsoever in Expert mode, the device will simply get the time from the timeserver.
Are you
sure that the time is getting reset by inbound calls? Reboot the device. Log into the device's local web page, and look at Status. Is the time correct? If so, it's fetching the time correctly. If not, then you've got some other issue, probably user error with whatever settings you have changed. I use
us.pool.ntp.org which has never failed to get the time. using
time.nist.gov may result in delays in response from the server, at which point the OBi may give up waiting for a response. This is a classic problem with MS Windows, by the way.
IF the time is correct, and then it gets reset when the phone rings, then you've got a hardware problem. If the power supply or the OBi is defective, the extra ring power needed, or a faulty telephone, could be causing the voltage to drop enough to make the device reboot. Watch the LEDs on the OBi when the phone rings. Do you see it reboot?
