Virtual Private Networking-VPN
A VPN supplies network connectivity over a possibly long physical distance. In this respect, a VPN is a form of Wide Area Network (WAN). VPNs enable file sharing, video conferencing and similar network services. Virtual private networks generally don't provide any new functionality that isn't already offered through alternative mechanisms, but a VPN implements those services more efficiently / cheaply in most cases.
A key feature of a VPN is its ability to work over both private networks as well as public networks like the Internet. Using a method called tunneling, a VPN use the same hardware infrastructure as existing Internet or intranet links. A VPN technology includes various security mechanisms to protect the virtual, private connections.
Specifically, a VPN supports at least three different modes of use:
1. Internet remote access client connections. People who have rights to access it will get internal access with ease and secure.
2. To support connections between multiple intranets within the same organization- Controlled access within an intranet. VPNs can also be used to separate the traffic of different user communities over an underlying network with strong security features, or to provide access to a network via customized or private routing mechanisms.
3. LAN-to-LAN internetworking-to join networks between two organizations, forming an extranet. You can connect your headquarter and branches which located in several location.
The main benefit of a VPN is the lower cost needed to support this technology compared to alternatives like traditional leased lines or remote access servers.
