The world has swiftly changed in the last couple of decades. Instead of simply dealing with local or regional concerns, individuals and organizations now have to think about global markets and logistics too. Nowadays, many companies have facilities spread out across the country and even worldwide. There is one thing that all of them need: A way to sustain fast, secure and reliable communications between their offices, wherever they are located geographically. As the company expands from one place to another, it makes the company to expand their network as well from one place to another. This all makes the company’s network more complex. The basic need to connect all locations remains there and efficiency with less cost is what every company looks for. Now the important point here is that security and reliability should not be compromised just because of low cost. The transportation of information must be secure and reliable. This is where a VPN comes in to play.

What is VPN?

A Virtual Private Network (VPN) is the extension of a private network that encompasses links across shared or public networks like the Internet. A VPN enables you to send data between two computers across a shared or public inter network in a manner that emulates the properties of a point-to-point private link. The act of configuring and creating a Virtual Private Network is known as Virtual Private networking.
The useful thing about VPN connections is that they also provide the functionality to organizations to have routed connections globally over a public inter network – such as the Internet, while maintaining secure communications
To emulate a point-to-point link, data is encapsulated (wrapped), with a header that provides routing information and hence allowing it to navigate the shared or public inter network to reach its destination or the endpoint. The data sent through a VPN is encrypted for confidentiality. Packets that are intercepted on the shared or public network are too hard to decipher (nearly impossible) without the encryption codes (keys). The link in which the private data is encapsulated and encrypted is known as a Virtual Private Network (VPN) Connection.

The useful thing about VPN connections is that they also provide the functionality to organizations to have routed connections globally over a public inter network – such as the Internet, while maintaining secure communications. A routed VPN connection across the Internet logically operates as a dedicated WAN link.

With both the remote access connection and with the routed connection, VPN connections allow an organization to trade in long distance dial-up or leased lines for local dial-up or leased lines to an Internet Service Provider (ISP).

VPN Security
A well-designed VPN uses several methods for keeping your connection and data secure, that are:
• Firewalls
• Encryption
• IpSec (Internet Protocol Security)
• AAA Server (Authentication, Authorization and Accounting).

VPN Tunneling

Most VPNs rely on tunneling to create a private network that reaches across the Internet. Essentially, tunneling is the process of placing an entire packet within another packet and sending it over a network.

Tunneling involves:

Carrier: Used by the network that the information is traveling over
Encapsulation: Wrapped around the original data.
Passenger: Original data that is being carried

What a company should look in VPN provider.

• Security
• Reliability
• Scalability
• Network management
• Policy management

If a company has more than one LAN, and has to communicate secure data on the LAN with employees, partners, vendors, consultants, telecommuters, branch offices or a sales staff, a VPN will more likely to improve its business efficiency while reducing cost.

The writer is currently doing Telecom Engineering from National University of Computer and Emerging Sciences (NU-FAST). He can be reached at sherrynaeem2@hotmail.com.