I used the book to build an NT 4.0 Server running PPTP. I found 2 undocumented procedures that had to be done in order for a client to connect to the server via an ISP. Worked like a charm. The speed is there, the security, and getting rid of the 800# saved my company about $3000/month which will be reflected in my next pay raise request.

Regarding the 2 undocumented procedures: I have submitted a notice to O'Reilly about the changes and will wait for them to verify my changes and post them.