We have an Atcom IP01 and we have checked all settings with TIMEOUT etc but cannot find why callers get a busy signal after two minutes (with NAT on) or disconnected (with NAT off). We are sure it is nothing to do with NAT but we cannot resolve this issue about callers getting disconnected or busy signal and then disconnected after two minutes. Our Atcom appliance is using Asterisk with Switchfin firmare. Any help will be much appreciated as we cannot use this appliance until we stop callers from getting disconnected, thanks.
Believe it or not it may be your router, try a different router.
thats a real good direction…nat or not, dmz (joke) or not.
What router is it?
It might also benefit you to call the people that sold you the thing.