ALL About VPN

A virtual private network (VPN) is a computer network that is layered on top of an underlying computer network. The private nature of a VPN means that the data travelling over the VPN is not generally visible, or is encapsulated from, the underlying network traffic. Similarly, the traffic within the VPN appears to the underlying network as just another traffic stream to be passed.
In more technical terms, the link layer protocols of the virtual network are said to be tunneled through the underlying transport network.

The term VPN can be used to describe many different network configurations and protocols. As such, it can become complex when trying to generalise about the characteristics of a VPN. Some of the more common uses of VPNs are described below, along with more detail about the various classification schemes and VPN models.

Common VPN uses

VPNs can be used to secure communications through the public Internet. VPNs are often installed by organizations to provide remote access to a secure organizational network, or to connect two network locations together using an insecure network to carry the traffic.

A VPN does not need to have explicit security features such as authentication or traffic encryption. For example, a network service provider could use VPNs to separate the traffic of multiple customers over an underlying network.

VPNs such as Tor can be used to mask the IP address of individual computers within the Internet in order, for instance, to surf the World Wide Web anonymously or to access location restricted services, such as Internet television.

How It Works ?

 

The 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, 128 Kbps) to OC3 (Optical Carrier-3, 155 Mbps) fiber, 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.
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.

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. In this article, you will gain a fundamental understanding of VPNs, and learn about basic VPN components, technologies, tunneling and security.
Virtual private networks help distant colleagues work together, much like desktop sharing.

What Makes a VPN?

A well-designed VPN can greatly benefit a company. For example, it can:
Extend geographic connectivity
Improve security
Reduce operational costs versus traditional WAN
Reduce transit time and transportation costs for remote users
Improve productivity
Simplify network topology
Provide global networking opportunities
Provide telecommuter support
Provide broadband networking compatibility
Provide faster ROI (return on investment) than traditional WAN
What features are needed in a well-designed VPN? It should incorporate:
Security
Reliability
Scalability
Network management
Policy management