Site Access Via Vpn

Landon and Pearson (2003) define Virtual Private Network (VPN) as a private secure network that grants (remote users) the access to internal networks via Internet with the use of Point-to-Point Tunneling Protocol (PPTP). In other words as O’Brien (2002) remarks VPN uses the Internet and its main backbone network together with the tunneling protocol and other security procedures in order to establish secure intranets and extranets.

Landon and Pearson (2003) say that remote users can access local ISPs through PPTP, where the latter establishes a connection between the ISP and the corporate network. They define this process as tunneling because a private connection is established by adding an invisible wrapper around a message to hide its content. Thus a secure connection is established, for example, between distant branch offices or manufacturing plants or among business partners.

According to Landon and Pearson (2003) PPTP is “an encoding mechanism that allows one local network to connect to another using the Internet as a conduit”. In other words PPTP makes it possible to create a virtual private network through "tunnels" (paths) over the Internet. The data is encrypted before it is send through the public network and is decrypted when it is received.

Landon and Landon (2002) suggest that the core purpose of VPN is to reduce communication costs. It provides the same capabilities as a private wide area network (WAN) but at lower costs by using the shared public infrastructure rather than a private one and is thus its alternative. As Tyson (2004) states this in fact means that the companies will prefer to use leased lines (such as ISDN or OC3) to maintain