Router will not allow me to access the internet.... We have not have phone service(Vonage) for

Question

We have not have phone service(Vonage) for three days, because we can not access the internet. I spoke with the internet provider(comcast), and picked up a new modem today. However, as long as I by-pass the router, I can get on the interenet, but I still don't have phone service. If I connect the router, it will not allow me to access the internet. I am VERY VERY frustrated.