I have a D-Link DI-604 model router (wired, not wireless) which I am trying to open certain ports to in order to use my VoIP phone, but it isn't working. It's possible that Comcast may have these blocked, but assuming that's not the case, I'm trying to troubleshoot the issue.
These ports and ranges need to be allowed to pass through:
What phone? What VOIP service? What is the complete port forwarding setup (i.e. post screen shots of the setup)? What is the IP address on your phone? That fact that you are using Windows 7 is irrelevant, the connection is between the router and the phone, your computer is not involved.