When I first puchased my Ooma Telo I had the same problem that you are having. I finally placed the Ooma Telo on the LAN side of the router (Modem-Router-Ooma Telo), and that move cured the problem that you were having. (If you make this move, you may or may not have some other minor problems that this form can help you with by giving you simple configuration and adjustment instructions).
Good Luck
Good Luck
