Incoming phone calls drop during first ring
Enthusiast - Level 3

Twice recently I've had no dialtone.  Both times, the troubleshooting tool said the problem was Verizon's, and had a ticket logged, yet both times, the technician came out and left a note that the problem was on the inside.  Yet mysteriously a couple hours after visit, the line worked again.  Both times I confirmed at the NID that I had no dialtone there, either.

Now, though, everytime the phone rings, it gets cut off during the first ring.  The caller ID shows up as "No Data".

I have DSL, which works fine this whole time, though I have a DSL splitter on the NID, and a separate line run just for DSL.

Any suggestions on things to check inside before I pay to have Verizon come out?

I've only tried one jack (only one phone plugged in in the house), but have tried multiple phones.