As organizations started spanning multiple sites, they started using WANs. What about the situations where organizations have offices spanning a number of countries? Surely connecting them with dedicated wires is no longer a cheap solution. An alternative solution that addresses most of the needs and is much more secure and reliable is that of Virtual Private Networks.
The Definition of a Virtual Private Network (VPN)?
There are a number of definitions of a Virtual Private Network depending upon which purpose it serves. The bits that are common and essential to every one of these definitions is that you use an existing network (generally a public network like the Internet) and then create a virtual network atop of that to serve some other purpose. To allow you to understand this better, let me give you an example.
Suppose your office has a network of computers which you make extensive use of when at work. Now one day you want to access your work from home, that is stored on the network computers. Obviously your home computer is not a part of the office network. You could remote login into your machine if that is an option and then use it as if you were present in the office.
The other option is that of VPN. It is a common practice these days to give employees access to VPN’s. With VPN you are essentially on the same office network although you may be at a different physical location. In this case the VPN would be configured to work over the Internet to give you access to the internal organization network.
You can thus exchange and share data as if on the internal organizational network although you are not directly connected to it. A VPN thus let you use the public network (the Internet in this case) to transmit private data.
How VPN’s Work?
There are two main technologies that facilitate the creation of VPN’s to allow you to transmit data safely and reliably over a public network. These are encryption and tunneling. Encryption in simple words, as you may know, is the act of scrambling data so that only the intended recipient can view or understand what you have sent and that it looks worthless and gibberish to other parties who may happen to view it.
Tunneling on the other hand refers to the act of creating a virtual tunnel of sorts where you place the contents of an entire packet into another packet to transmit it over the public network. The encapsulating protocol is so chosen that it is not understood by other computers or network devices over the public network which the packets may pass through.
The result of putting these two together is that you can now transmit your data without having to worry about security and reliability issues over the public network.
Advantages Of Using VPN’s
As would be clear by now, one can easily use VPN’s to connect multiple sites (think branch offices) onto the main corporate network and to gain remote access to internal organizational networks (or even your home network for that matter). It is also the cheaper solution in most of the cases when compared with traditional WANs. VPN’s are secure and offer reasonably good performance with high reliability.
Have you ever configured a VPN? What software did you use?