The standard setup is to have one NIC on the private LAN and one
connected to the Internet. If you already have an Internet connection
through a router, you can use this as your public interface. You would
configure the RRAS server (with one NIC) as a remote access server. Test the
config using a LAN machine connecting to the server's LAN IP. When this
works, forward tcp port 1723 from the router to the RRAS server. Now try
connecting over the Internet to the router's public interface.