VPN - Virtual Private Network - is one solution to establishing long-distance and/or secured network connections. VPNs are normally implemented (deployed) by businesses or organizations rather than by individuals, but virtual networks can be reached from inside a home network. Compared to other technologies, VPNs offers several advantages, particularly benefits for wireless local area networking.

For an organization looking to provide a secured network infrastructure for its client base, a VPN offers two main advantages over alternative technologies: cost savings, and network scalability. To the clients accessing these networks, VPNs also bring some benefits of ease of use.

Cost Savings with a VPN

A VPN can save an organization money in several situations:

* eliminating the need for expensive long-distance leased lines
* reducing long-distance telephone charges
* offloading support costs

VPNs vs leased lines - Organizations historically needed to rent network capacity such as T1 lines to achieve full, secured connectivity between their office locations. With a VPN, you use public network infrastructure including the Internet to make these connections and tap into that virtual network through much cheaper local leased lines or even just broadband connections to a nearby Internet Service Provider (ISP).

Long distance phone charges - A VPN also can replace remote access servers and long-distance dialup network connections commonly used in the past by business travelers needing to access to their company intranet. For example, with an Internet VPN, clients need only connect to the nearest service provider’s access point that is usually local.

Support costs - With VPNs, the cost of maintaining servers tends to be less than other approaches because organizations can outsource the needed support from professional third-party service providers. These provides enjoy a much lower cost structure through economy of scale by servicing many business clients.

VPN Network Scalability
The cost to an organization of building a dedicated private network may be reasonable at first but increases exponentially as the organization grows. A company with two branch offices, for example, can deploy just one dedicated line to connect the two locations, but 4 branch offices require 6 lines to directly connect them to each other, 6 branch offices need 15 lines, and so on.

Internet based VPNs avoid this scalability problem by simply tapping into the the public lines and network capability readily available. Particularly for remote and international locations, an Internet VPN offers superior reach and quality of service.

Using a VPN
To use a VPN, each client must possess the appropriate networking software or hardware support on their local network and computers. When set up properly, VPN solutions are easy to use and sometimes can be made to work automatically as part of network sign on.

VPN technology also works well with WiFi local area networking. Some organizations use VPNs to secure wireless connections to their local access points when working inside the office. These solutions provide strong protection without affecting performance excessively.

Limitations of a VPN
Despite their popularity, VPNs are not perfect and limitations exist as is true for any technology. Organizations should consider issues like the below when deploying and using virtual private networks in their operations:

1. VPNs require detailed understanding of network security issues and careful installation / configuration to ensure sufficient protection on a public network like the Internet.

2. The reliability and performance of an Internet-based VPN is not under an organization’s direct control. Instead, the solution relies on an ISP and their quality of service.

3. Historically, VPN products and solutions from different vendors have not always been compatible due to issues with VPN technology standards. Attempting to mix and match equipment may cause technical problems, and using equipment from one provider may not give as great a cost savings.