The business world has changed a lot in the last couple of decades. Instead of simply dealing with local or regional concerns, many businesses now have to think about global markets and logistics. Many companies have facilities spread out across the country or around the world, and there is one thing that all of them need: A way to maintain fast, secure and reliable communications wherever their offices are. Until fairly recently, this has meant the use of leased lines to maintain a Wide Area Network (WAN). Leased lines, ranging from ISDN (Integrated Services Digital Network) to Fibre Optic connections, provided a company with a way to expand its private network beyond its immediate geographic area. A WAN had obvious advantages over a public network like the Internet when it came to reliability, performance and security. But maintaining a WAN, particularly when using leased lines, can become quite expensive and often rises in cost as the distance between the offices increases.

Many companies are creating their own VPNs (virtual private network) to accommodate the needs of remote employees and distant offices. Basically, a VPN is a private network that uses a public network (usually the Internet via ADSL) to connect remote sites or users together. Instead of using a dedicated, real-world connection such as leased line, a VPN uses "virtual" connections routed through the Internet from the company's private network to the remote site or employee.