Some times we choose to work from home reason can be anything either we are not well or due to double income family our spouse want us to stay with kids or even if we are traveling for some business purpose we want to connect to corporate server. In all these cases as an individual, we would like to access all of the same amenities (programs, emails, etc) as working in the office.

VPN technology allows users to work from home or on the road to connect (connect using Mobile wi-fi) in a secure fashion to a remote corporate server using the routing infrastructure provided by a public network like Internet. It’s not only that a user can connect from home to office, but VPN technology also allows a corporation to connect to branch offices or to other companies over a public network.. In doing so it maintains the secure communication.

VPN stands for Virtual Private Network. The main benefit of a VPN is the lower cost needed to support this technology as compared to other alternative technologies like leased lines or RAS (remote access server).

Why it is known as Virtual Private Network?

VPN is virtual because the secure connection across the public network appears to the user as a private network communication despite the fact that this communication occurs over a public network. While utilizing public network, it does not sacrifice features of basic security

As we know corporate environment should be tightly secure, this is achieved by creating virtual private network on top of the normal public network. This type of connection is very secure and its encrypted, and also only authenticated user can access to corporate amenities this is also made sure that data, which is being sent to, or coming from corporate is not intercepted.

So how VPN works then?

VPN follows client and server approach, so two components are required to make this scenario work. If we are a remote client and want to connect to corporate server, there should be corporate server setup, which should have server VPN software installed. As a client your system should have VPN client software installed.

For communication on the Internet VPN client software communicates with VPN corporate server software. VPN server authenticates the validity of client; if client proofs its validity then access by the server granted.

With the VPN, data is carried over the Internet through a process called tunneling. Tunneling is generally done by encapsulating the private network data and protocol information within the public network transmission unit, so that the private network protocol information appears to the public network as data.

In simple terms we can say, tunneling allows the use of Internet, which is a public network, to send data on behalf of private network.

One more thing needs to know, when the information to or from the client to the server is traveling along virtual private network, the additional layer of encryption and security protects it.

VPN uses two major protocols. Microsoft network uses PPTP or Point-to-Point Tunneling Protocol and other network uses IPSec - Internet Protocol Security.

Common uses of VPN.=

Here I am describing some more common VPN situation.

• Remote access client connections.
  VPN provides remote access to corporate resources over the public Internet, which maintains privacy of information.
  To log in to a dial up intranet, a remote client must call local ISP. Using the connection to the local ISP, the VPN software creates a virtual private network between the dial-up user and the corporate VPN server across the Internet.
• Connecting networks over the Internet.
  VPN also allows an entire remote network rather than a single client to join the local network. In this case, two networks joined by server-server VPN connections rather than a client-server connection.
• Security features of VPN
  Security features of VPN allow this technology for the implementation of controlled access to individual subnet on the private network.

The VPN technology must ensure the privacy and integrity of data as it traverses the Internet. Therefore VPN solution should provide:

User Authentication.
Address Management.
Data Encryption.
Multiple Protocol Support.

In conclusion VPN is a great option for business either small or large that have remote employees, need site-to-site access with remote offices or secure dial-up-connections.