On Mon, 08 Aug 2016 11:11:17 -0400, J.B. Wood wrote:

Hello, all and a new POTS Verizon problem:

My OP about the ability to receive incoming but not able to dial out or
have the calling party hear the called party was explained as a faulty
2-wire/4-wire interface issue which I understood. I had called Verizon
service and the phone was restored to normal operation after about 4
days. I don't know exactly what was done (if anything). Phone service
has been OK for about 2 weeks.

Last Sunday that same phone line displayed a new symptom - no dial tone
but the DTMF keypad produces audio and there is noise on the line (like
what you hear between entering the digits of a phone number). Attempting
to dial the problem phone number from a cell phone resulted in a busy
signal. It wasn't an off-hook situation as you could hear a definite
switching action when a phone on the problem line was taken off hook.
Ditto for any one of the 3 extensions sharing the line. This morning,
Monday, the phone line was operating as expected. Very mysterious
goings on here. Sincerely,

Look for corrosion at the entry demarcation and clean.