IP VPN: compelling savings - compelling performance?
A Virtual Private Network (VPN) enables organisations to use a shared network - typically the Internet or an IP backbone supplied by a network service provider - to connect remote sites or users together.
Instead of using only dedicated connections (such as a leased line), a VPN makes use of "virtual" connections routed across the shared network to link a company's private network to remote sites or employees. Leased lines may still be used to connect the customer site to the edge of the shared network or, for internet based VPN's ADSL or ISDN may be used to connect to the shared core.
The goal of a VPN deployment is to provide the organisation with the same capabilities as a dedicated Wide Area Network (WAN), but at a much lower cost. Typically WANs are built using leased lines, which become progressively more expensive as the number of branch offices, and the distance between them, increases.
VPNs represent a way to neatly avoid this cost without - subject to proper implementation - sacrificing the security associated with leased-line circuits.
