Please help! I am trying to make a call with Zoiper and the phone line keeps dropping; it will say opening port, early media, show that a call is being made.... but I can't hear it ringing and apparently the other person can hear me, but I can't hear them. When I restart my computer, Zoiper seems to function again. What is going on? I can't keep dropping calls as my job depends on it. Is it an internet issue? Computer issue? Please help.
I have Windows 10, Toshiba Satellite, free AVG. It doesn't seem to be a firewall issue as I did have someone look at that.