Verizon is our phone /internet provider. I connected the fax machine. When an incoming call is received, more often than not, the fax gurgling interrupts the call and eventually kicks into the fax screech. The only way to stop this is to go to the fax machine and hit the STOP button. Somehow the fax machine is not distinguishing between a voice and fax call. Parameter #15 is set to 2 (Fax/Tel SW). Any help appreciated.