voice modem not powering home phone wall jacks

We have our own modem with voice (Netgear CM1150V). Recently activated our xfinity voice service, it is (finally) working. I say finally because there were glitches porting our number over. All is working now. When I plug a phone directly into the modem, that phone works. When I plug the modem directly into the wall jack to give all the phone jacks in the house dial tone- nothing. I've disconnected the old land line wires at the box on the outside of the house. I know all my internal phone wiring works (because it did the last day we had a land line). I'm at a loss of why this isn't working. I've asked on the Netgear website, no help there. So thought I'd try here as other likely have the same modem. Thanks in advance!