The question of how exactly to explain or define a VPN is one often debated among today’s network consumers and communications providers. If we look at the literal definition of the words virtual private network, it can help to understand what a VPN is and is not.
Using Webster’s dictionary definitions of component words, a VPN should have the following attributes:
Virtual: defined as “being such in practice or effect, though not in actual fact or name.” Therefore, the first part of the answer to our question “what is a VPN?” it’s that it’s something that acts like a wired network, but it really isn’t.
Private: defined as “of, belonging to, or relating to a particular person or group; not common or general.” Therefore, a VPN must be one in which the consumer has exclusive use of the network links. (Note that this is different from a secure network, which can be a private or public network.)
Network: defined as “a system of computers interconnected by telephone cables or other means of sharing information.” This is the goal of a VPN or any other type of network.
VPN explained in this way is a network technology that gives the owner the ability to share information with others on the network by means of a private and exclusive link that is created by a method other than cabling or leased lines; usually through the Internet. Before the Internet, computers in different offices, cities, or even countries could only communicate with each other the way people did: over telephone wires. As the needs for this type of communication grew, telephone lines were replaced by larger volume cables such as T3 circuits, but the concept was the same.
In order for computer A to communicate with computer B, there had to be a physical wired connection. For security reasons, you’ll want to make sure that only your 2 computers use that line, so you’d hire a provider to “lease” that circuit. However, this type of network was expensive and difficult to expand, not to mention difficult for the customer to gain control over.
With the advent of the Internet, connections no longer need to be physical. As long as each computer has Internet access, information can be shared across local ISP circuits, across the Internet, and to the recipient in the same way as when the computers were physically connected. That’s why the way VPN works is considered a “virtual” network; all connection is not wired.
The VPN aspects explained in this article have so far not yet discussed an ever-present concern in today’s world: security. In an old WAN arrangement, the security of data transmission could depend entirely on the provider’s guarantees. Today, however, a VPN keeps information private by encrypting it on both the sending and receiving end. There are a variety of encryption protocols, depending on what a business needs, who it needs to communicate with (and therefore be compatible with), etc. The data is not only encrypted, but also encapsulated, which means it is sent in its own private “tunnel” or connection over the Internet. No one can see the data, and even if they could, they can’t decrypt or change it. In this way, information can be sent over the Internet without being susceptible to interception or corruption by those outside of the VPN.
To create a virtual private network, you need to decide who needs to share information, in which directions, and how often. Next, you will need to prepare a list of the hardware and software systems you are currently using at each location. You may very well need to make changes so that the computers can communicate with each other easily. You’ll also want to consider how important it is that your data remains secure, as this will impact the type of protocol you select. Preparing this information will prepare you for the discussions you will need to have with potential suppliers.