(
Point-to-
Point
Tunneling
Protocol) A protocol from Microsoft that is used to create a virtual private network (VPN) over the Internet. Remote users can access their corporate networks via an ISP that supports PPTP.
PPTP encapsulates all network protocols for transport over IP. If IP is the source, IP packets ride as encrypted messages inside PPTP packets running over IP. PPTP is based on the point-to-point protocol (PPP) protocol and the generic routing encapsulation (GRE) protocol. Encryption is performed by Microsoft's Point-to-Point Encryption (MPPE), which is based on RC4. See
L2TP and
VPN protocols.