Just out of curiosity, could PPTP be used with TLS. My first understanding is that TLS is for a short term connection for authentication, so how could it used? I only asked because I saw a very old posting on the internet that indicated that Microsoft advises to use EAP-TLS with PPTP, which didn't really make sense to me, but technically it isn't going to give a encryption, could I get some input on this one. Thanks.
I have to admit that I do not have any first hand experience in this, but from research, PPTP is not an authenticating protocol (meaning its not written to communicate between AS server and client). It is a legacy L3 encryption protocol, which means data. In addition, TLS is strongly advised to be used for legacy authenticating protocols ie.PAP AND CHAP. Maybe that's what you saw?
(and they talk about the 802.11 alphabet soup!!)