A real private network is coupled by dedicated private lines. A virtual private network is coupled by encrypted data sent over public data paths. On the positive side, VPNs allow users anywhere that has internet (or other global network) access to connect to servers or peers anywhere on the net. Further access is controlled by the sever/peer as if the users were local. In almost all cases, the connections will be made by low cost local telephone calls or dedicated broadband connections rather than a higher tariff longer distance phone line. The downside is that VPNs provide a tunnel through which intruders can penetrate firewalls if any defects exist in the VPN setup.
The major technical problems with VPNs are the issues of establishing and maintaining secure "private" links through a public message space. A variety of technologies have been proposed for VPNs. Several commercial products are available as of Q3 2001.
Return To Index Copyright 1994-2002 by Donald Kenney.