PPP and PPTP guide - Point to Point tunneling Protocol
PPTP (Point to Point tunneling protocol)
PPTP is a protocol or technology that supports the use of VPN’s. Using PPTP, remote users can access their corporate networks securely, using the Microsoft Windows Platforms and other PPP (Point to Point tunneling Protocols) enabled systems. This is achieved with remote users dialing into their local internet security providers, to connect securely to their networks via the internet. PPP (Point to point protocol) is used by PPTP to provide the encryption and authentication on data packets. The main use of PPTP is to provide a tunnel for PPP, as PPP is none routable over the internet.
PPTP is a tunneling protocol that was developed by various vendor companies including Microsoft and AS Robotics. PPTP has its issues and is considered as a weak security protocol according to many experts, although Microsoft continues to improve the use of PPTP, and claims issues within PPTP have now been corrected. PPTP is not as secure as IPSec and cannot secure two networks. PPTP can only secure one IP address with one other IP address or with a network. PPTP is now often replaced by L2TP which provides security using IPSec, and PPTP has also been made obsolete by L2TP and IPSec. Lastly another limitation PPTP has compared to L2TP is that it can not route over other networks other than IP.
Although PPTP is easier to use and configure than IPSec, IPSec outweighs PPTP in other areas such as being more secure and a robust protocol.
Also see IPsec
Wikipedia's guide to PPTP (Point to Point Tunneling Protocol)