The technology sector is at the moment somewhat confused about what a VPN actually is. However the confusion is understandable as the VPN has continually evolved over the last few years into a somewhat different networking technology. In the passed, the VPN could be described as a private network which is able to carry voice and data usually built into existing carrier services.
This is not how a VPN is defined commonly today, it’s probably best to split into the following different definitions.
- Voice VPN – a single carrier which handle all the voice call switching. The ‘virtual’ in VPN here implies that a virtual voice switching network has been created within the switching equipment. This is probably the most dated definition under the concept of traditional carrier based voice vpns.
- Carrier Based Data VPN – Traditional packet, cell switching and frame networks normally carry data in discrete bundles which are then routed through a complex mesh of networks and switches to their destination. These networks would be shared between many owners and users. A VPN would be a web of individual virtual circuits which form a virtual private network over another carriers packet-switched network.
- Internet VPN – this is probably the definition which is most relevant today, similar to the previous carrier based data network. Here an IP network is the underlying transport and the common medium the shared hardware of the internet.
The internet VPN like this is the most common today probably because it is by far the easiest and cheapest one to set up. There might not be the same bandwidth and data quality guarantees than a traditional virtual circuit, however the popularity of simple VPN client and server accessible from anywhere in the world is a powerful tool for many reasons.
What’s more the internet VPN can be created and used by almost anyone without exception. Companies for instance will often install generic VPN client software on their laptops so any employee can dial in to the corporate servers using any internet connection safely and securely. This means that employees can work remotely from almost any location all they need is a simple internet connection and an account on the VPN server.
A decade ago these were used over simple dial up modems but now most countries have a fairly large internet access infrastructure allowing high speed access from most public places and from home internet connection. The other advantage is that an internet VPN requires no real investment in hardware apart from the central server. Users can leverage the internet connection of their ISP or even a hotel wifi access point, a fairly insecure setup but if you connect through a virtual private network then all your data is securely encrypted and protected from prying eyes.