Virtual Private Networks

Virtual Private Network, Its ‘Virtual', Its ‘Private' and it's a ‘Network'. A virtual private network (VPN) provides a secure connection between a sender and a receiver over a public non-secure network such as the Internet. A secure connection is generally associated with private networks. (A private network is a network that is owned, or at least controlled via leased lines, by an organization.). We can define a VPN by the following relationship: VPN = Tunneling + Security + QoS Parameters. This Chapter deals with Advantages of VPNs, Types of VPNs, VPN Architectures, VPN Models, VPN Devices, Technologies and Protocols Used to Enable Remote Access VPNs.