Voice Service Not Working

I added my own modem to my xfinity services (Netgear CM500V) after having trouble connecting to the internet with Xfinity's modem (voice worked fine on their modem). I'm now able to connect to the internet with this modem, however, I'm having trouble activating the voice service on it. There's no dial tone on my landline and the phone symbol on the modem is not lit up. I have the phone connected to the modem via a phone jack.