Hi, I've got 3cx configured with SPA3102. The outbound gateway is a Patton 4960 T1/E1 circuit. The SPA3102 is configured to a normal fax machine. Sending faxes and receiving faxes work most of the time. There are certain fax numbers (which I've narrowed down to interstate and remote areas) where faxes are not reaching or received. The fax machine picks up the call, negotiates for a bit and then cuts off. Any idea what's happening here?