Go to the Port Forwarding page and put those ports in along with TiVo's IP address. You might have to turn off DHCP to do this, but I don't think so. If you are able to leave DHCP on, you'll have to update the table anytime the TiVo get's a new IP address (which would typically happen if the TiVo or the Router loses power or resets, but even then it might get the same one back)