I have an intermittent problem with my POTS phone which has been occurring for a few weeks. The POTS phone line is provided by Bell but the service is provided by a company which buys Bell services then resells to subscribers. When a phone's handset is picked-up, there's no dial-tone and the line is dead as though nothing is connected to it. When that occurs, if the phone number is dialed from another phone number, such as a cell phone, the line beeps 3 times and the line is dead and "line disconnected" appears on the cell phone screen and no audio message. All the inside wiring checks out OK as do all of the phones. Bell checked the line from the pole into my house and it is also working fine, clear as a Bell. I told the Bell tech that the problem is elsewhere, between the pole and the C.O. and/or at the C.O. The problem occurs regardless of the weather, sun and shine and when it rains, so I don't think the problem is weather related. The phone service reseller's tech rep says that they're having the same problem with other subscribers on the system. What could the problem be?