VPN

The world has changed a lot in the last couple of decades and 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 recently, the use wide area network (WAN)., the Leased lines, ranging from ISDN (integrated services digital network, 128 Kbps) to OC3 (Optical Carrier-3, 155 Mbps) fiber, provided a company the only 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.

As the popularity of the Internet grew, businesses turned to it as a means of extending their own networks. First came intranets, which are password-protected sites designed for use only by company employees. Now, many companies are creating their own VPN (virtual private network) to accommodate the needs of remote employees and distant offices.

A typical VPN might have a main LAN at the corporate headquarters of a company, other LANs at remote offices or facilities and individual users connecting from out in the field.


Basically, a VPN is a private network that uses a public network (usually the Internet) 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.