VPN

VPN is an abbreviation of Virtual Private Network. It means a hardware or software solution by which the internal network of an organisation can be safely extended over an unsafe public network, like the Internet.

The VPN techniques are used either to combine two or more internal networks with each other or to connect a single communication device, for instance the workstation of a remote worker or a partner, to the organisation’s network. In the VPN the data transferred is encrypted, which prevents the contents transmitted in the public network to be disclosed to third parties. Besides the encryption of communication, the operating parties are strongly authenticated before the connection is established.

In practice, a VPN connection is created by tunnelling all traffic inside some protocol which encrypts the traffic. Generally used VPN protocols are IPSec (Internet Protocol Security), L2TP (Layer 2 Tunneling Protocol) and PPTP (Point to Point Tunneling Protocol). All traffic sent in the VPN tunnel over the unsafe network can be protected by VPN techniques, and the protection is not then dependent of the protocols at the application level.