PPTP and Virtual Private Networking

The PPTP protocol is included with the Windows NT® Server version 4.0 and Windows NT Workstation version 4.0 operating systems, and a beta version is available as an add-on for the Windows® 95 operating system. Computers running these operating systems can use the PPTP protocol to securely connect to a private network as a remote access client by using a public data network such as the Internet. In other words, PPTP enables on-demand, virtual private networks over the Internet or other public TCP/IP-based data networks. PPTP can also be used by computers connected to a LAN to create a virtual private network across the LAN.

An important feature in the use of PPTP is its support for virtual private networking through public-switched telephone networks (PSTNs). PPTP simplifies and reduces the cost of deploying an enterprise-wide, remote access solution for remote or mobile users because it provides secure and encrypted communications over public telephone lines and the Internet. PPTP eliminates the need for expensive, leased-line or private enterprise-dedicated communication servers because you can use PPTP over PSTN lines.

Generally, there are three computers involved in every PPTP deployment:

·a PPTP client

·a network access server

·a PPTP server

However, if you are creating a PPTP tunnel between a PPTP client and a PPTP server that are both connected to the same LAN, you do not need a network access server.

The following section describes a typical PPTP scenario using these computers and explains how they relate to each other, It also fully defines each of these components.