Is it Imperative to have an internet connection?

I have been selling Asterisk based systems for about two years. We have one system where the customer does not have an internet connection, just some phones (6), a Gateway and the system. They do have a PC that uses a wireless Hotspot for the occasional email. My system manufacturer insists that the system was made for the internet and must have an internet connection to run properly. Granted the clock drifts off like going over a cliff in a couple of days. They have to connect to the programming GUI and set the clock from a PC. I have stressed to them that they need a real internet connection. I don’t know if they will, they are a seasonal store. So my question to all the gurus: Besides the Time Server needed, what does an Asterisk system need from the internet? My manufacturer either won’t or can’t tell me if they are doing anything.

Thanks

No. You will actually get better quality timing if you don’t use the internet but go directly to a radio (or local atomic!) clock. Phase locking to TAI is not actually essential.

You may need to go authoritative for in-addr.arpa, or disable BIND for name resolution.

Asterisk does NOT need an internet connection for normal operation. If the server system clock drifts unexpectedly, then you might have a problem with server hardware.

These systems are pretty locked down, so I can’t fuss with the OS or any of the settings you guys have suggested. The hardware clock in the MB must be a poor design. So the MB the system is running on is probably a poor quality to not keep the clock even somewhat close to real time for a couple of weeks. But their assertion that the system is or needs to be connected to the internet would be their requirement for some unknown reason and not that Asterisk needs it. Right?

Thanks