VPNs use security encryption tunneling protocols to provide packet sniffing protection, they guarantee adequate authentication, and declare the integrity of the messages, i.e. their entirety.
The components necessary to build a VPN connection are:
This type of VPN connection is used to connect geographically sparse locations in a similar way as if they were connected by a leased line or another WAN (Wide Area Network), (e.g. Frame-Relay, ATM (Asynchronous Transfer Mode)). The advantage of such a link is sharing a corporate intranet or an extranet with a partner. In this topology, users send and receive data via a VPN gateway, usually a router or a server. The VPN gateway is responsible for encrypting outbound traffic and routing it to the VPN tunnel through the Internet to the opposite VPN gateway of a target network. This VPN gateway removes the packet header, decrypts its content, and delivers the packet to a target user within the target network.
Terrain workers or home workers use remote access VPN connections a lot. In the past, these remote workers had a connection by telephone lines, which meant a low transmission rate associated with high operating costs. At present, however, most of them have fast internet access directly from home through broadband technologies and can build high-quality VPN connections.
Each user typically has a VPN client installed, that is, a software that encapsulates and encrypts packets before sending them over the Internet to the destination VPN gateway. This software makes it much easier to connect, because the user only needs basic knowledge to build a high-quality VPN connection.