Hello shadowthax, welcome to PCHF.
No, it's not possible to set a fax machine up on a router. Not sure what your trying to achive there? A fax machine should be connected to your telephone line directly or through your broadband filter.
A router connects to the internet in a very different way than a phone or a fax machine does. You cannot ring a router, and you cannot dial a telephone number using a router, you are connected directly to your ISP. When you have a phone or fax machine connected, you can dial a number, and receive calls on your home telephone number.
EDIT: Marked as Answered.
