Softether is an excellent program: Thank you to all the developers for making it freely available. It has solved a long standing issue for me, which is that Windows RRAS doesn't work very well, and tended to cause our servers to crash. Since switching off RRAS and using Softether on a different machine, we have found Windows to be much more stable, and the connection is absolutely solid.
Thanks again, guys, Ari Gato, you did a great job!