<http://www.ietf.org/rfc/rfc2548.txt> MS RADIUS Attributes
You might be interested in PoPToP, a Linux PPTP server. You can find it at
-<http://poptop.sourceforge.net/>.
+<http://www.poptop.org/>
RADIUS support for MPPE is from Ralf Hofmann, <ralf.hofmann@elvido.net>.