Once you're set up, there's very little (or rather none) maintenance.
Let's start with call volume. A pay as you go provider like voip.ms may not make sense if your call volume is thousands or tens of thousands a minute a month.
Nope. That's why I'm on the internet arguing with strangers. If I had anything better to do I'd probably be doing it.Do you not have anything else to do rather than argue with strangers on the internet