The term VPN has been associated in the past with such remote connectivity services as the (PSTN), Public Switched Telephone Network but VPN networks have finally started to be linked with IP-based data networking. Before IP based networking corporations had expended considerable amounts of time and resources, to set up complex private networks, now commonly called Intranets. These networks were installed using costly leased line services, Frame Relay, and ATM to incorporate remote users. For the smaller sites and mobile workers on the remote end, companies supplemented their networks with remote access servers or ISDN. Today’s VPN solutions overcome the security factor using special tunneling protocols and complex encryption procedures, data integrity and privacy is achieved, and the new connection produces what seems to be a dedicated point-to point connection. And, because these operations occur over a public network, VPNs can cost significantly less to implement than privately owned or leased services. Although early VPNs required extensive expertise to implement, technology has matured to a level where deployment can be a simple and affordable solution for businesses of all sizes.
