Virtual Private Network (VPN)A virtual private network is a way to simulate a private network over a public network, such as the Internet. It is called "virtual" because it depends on the use of virtual connections-that is, temporary connections that have no real physical presence, but consist of packets routed over various machines on the internet on an ad hoc basis. Secure virtual connections are created between two machines, a machine and network, or two networks.
A VPN connection of networks is done using leased lines such as frame relay, ISDN, DSL or a T-1 line. Frame relay lines can give you high speeds without the mileage charges. Unlike a point to point private line, the amount you pay is based on the bandwidth that's committed to your circuit instead of the distance between locations.
Thus, VPN is a cost-effective way for an organization to connect its networks at multiple locations.
