Here's how my Vonage cabling turned out. I couldn't find any cheap punchdown boards or splice connectors in the stores (New Jersey stores, even the big chain stores, run weak in variety) but I bought a couple of wall connectors. I attached them to the telco plank and hooked everything up to the terminals with what I hoped were sound connections. Still no dial tone.
After much experimenting along these lines, I turned my attention to the cable that ran along the walls from the old demarc to the Vonage device. I unplugged the connector at the Vonage end. It was fused.
I replaced it with a new twenty-foot cable with jacks at both ends. Now it works.
The old demarc still has two telco cables attached, and I could call out on the live one even after Verizon ceded my phone number to Vonage. Perhaps I still can. I'm not going to make the experiment.
You may wonder how I happen to have an old, active demarcation point inside my house. When I bought the house in 1989 it had one line, and I later added a second for data. When my children reached teen age I added two more. The old demarc had room for only two, so New Jersey Bell put a modern demarc box on the side of my house and ran the new lines through it. But the tech left the old lines entering and leaving the telco side of the box and running to the old demarc point!
My children got cell phones and I dropped the two new lines. We got cable internet service and I dropped the data line. This left only the original line--still using the old demarc point in my basement.
Thanks to all who responded. One of these days I'll have the house rewired for the 21st century!
-:- In any case, by the end of the Ordovician period the Oral- Aural Coral had developed a sophisticated culture which compares favorably with those of ancient Sumeria, medieval Wales, and Texas.
--Melanogaster J. Spigot, Ph.D., "On the Neurobiology and Endocrinology of Some Prehistoric Coelenterates"