Virtual Private Network - Advantages and Disadvantages

VPN

Introduction:

VPN stands for Virtual Private Network. VPN is a data network connection that makes use of the public telecommunication infrastructure but maintains privacy through the use of a tunneling protocol and security procedures. It operates much like a Wide Area Network (WAN).

Most companies actually leased lines, but in either case both solutions are very expensive. As the Internet became more widely available people started creating VPN solutions that took advantage of the cheap network access. The idea was to use the Internet's existing links to create a virtual circuit.

Advantages and Disadvantages of VPN:

Virtual Private Network presents some advantages over the traditional network technologies. VPN offers direct cost savings over leased lines or long-distance calls for remote access, savings resulting from reduced training requirements and equipment, increased flexibility, scalability, and security. The main advantage of VPN is the cost savings of Internet VPN when compared to networks built using conventional leased lines. Leased lines include tariffs that have an installation fee, a fixed monthly cost, and a mileage charge. The cost to an organization of traditional leased lines may be reasonable at first but can increase exponentially as the organization grows. As an organization grows and more companies must be added to the network, the number of leased lines required increases dramatically. VPN that utilizes the Internet avoids this problem by simply tapping into the geographically distributed access already available. Another way VPN reduces costs is by reducing the need for long-distance telephone charges for remote access. Instead of having the offsite team of a company dial into the corporate modem bank via long distance lines, the company's VPN allows them to simply place local calls to the ISP's POP in order to connect to the corporate network.

Moreover, VPN allows the creation a secure private network over a public network such as the Internet.

Although VPN is very popular in the market for networking technology, it may raise some concerns for IT managers. VPN requires an in-depth understanding of public network security issues and proper deployment precautions. The task of choosing and deploying a VPN solution is far from being simple and may require the training of workers in at least the basics of VPN client to ensure the efficiency and to maximize the use of this technology. Secondly, the availability and performance of an organization's wide-area VPN (over the Internet in particular) depends on the factors largely outside of their control. The traffic congestion and the router failures on the Internet, for instance, can adversely impact the performance of VPN. Thirdly, VPN technologies from different vendors may not work well together due to a lack of standards. Finally, VPNs need to accommodate protocols other than IP and existing internal network technology to facilitate their use with different infrastructures (Hardware and Software).

Nevertheless, these disadvantages don't necessarily outweigh VPN advantages.

It's not quite easy to pinpoint the price of a VPN system because it depends on the features and infrastructure a firm chooses to have in its system to better serve its needs. (1)

Implementations of VPN:

Intranet: In Intranet VPNs that facilitate secure communications between a company's internal departments and its branch offices, the primary technology requirements are strong data encryption to protect sensitive information; reliability to ensure the prioritization of mission-critical applications, such as ERP systems, sales and customer database management, and document exchange; and scalable management to accommodate a growing number of new users, new offices and new applications.

Remote Access: Remote Access VPNs between a corporate network and remote and/or mobile employees have different requirements. Strong authentication is critical to verify remote and mobile users' identities in the most accurate and efficient manner possible. On the management side, Remote Access VPNs require centralized management and a high degree of scalability to handle the vast number of users accessing the VPN.

Extranet: Extranet VPNs between a company and its strategic partners, customers and suppliers require an open, standards-based solution to ensure interoperability with the various solutions that the business partners might implement. The accepted standard for Internet-based VPN is the Internet Protocol Security (IPSec) standard. Equally important is traffic control to eliminate bottlenecks at network access points and guarantee swift delivery of and rapid response times for critical data. (A)

VPN Protocols:

One of the most popular protocols for VPN is PPTP, which stands for Point-to-Point Tunneling Protocol. PPTP is actually an extension to PPP (Point-to-Point