Nearly every day, for serveral hours, my home phone line is unusable. I have a "line in use" message on the phone. When this happens I cannot make or receive calls on my phone. I still have a dial tone but, if I try to make a call, I hear beeping noises that sound similar to a fax machine. The problem eventually clears itself after several hours.
If I Google "Verizon Line In Use" I see that I am not alone in having this problem. Any ideas on possible causes?