Vpn As A T-1 Circuit Alternative

VPN as a T-1 Circuit Alternative

Today's business environments demand employees to be connected to corporate intranet resources from remote offices or while traveling. High bandwidth internet connections have made long-distance dial-up connections obsolete and have given birth to a newer technology called the Virtual Private Network (VPN) which can be characterized by a client server approach and is a form of a Wide Area Network (WAN). "VPN clients authenticate users, encrypt data, and otherwise manage sessions with VPN servers utilizing a technique called tunneling" (Mitchell, n.d.a).

What is a VPN?

A VPN is a "communications network tunneled through another network and dedicated for a specific network" (Wikipedia, 2007). A traditional VPN uses the internet (public communication) to communicate directly with a single network (private communication).

Science fiction buffs may also relate a VPN to a wormhole due to its tunneling characteristics between the client and the server.

The term VPN was originally introduced by telecom companies. "The main feature of a telephone VPN is that it can provide users from an organization which uses a public provider's telephone service instead of its own private PBX with something very close to PBX (Private Branch Exchange) functionality" (Olifer, 2007).

Why use a VPN?

VPN solutions become attractive when the need to provide secured long distance access to a private network arises. The traditional method of accomplishing this was to install a high-speed digital link such as a T-1 (or fractional T-1) between the locations or use a remote access server (RAS), or modem pools, incurring long-distance telephone fees.

A dedicated point-to-point communication line such as a T-1 can offer a 1.544-Mbps transmission rate (or multiples of) and can be very costly - between $550 and $1,200 a month. (T1 Shopper, 2007). This may be an acceptable approach but does not scale well when trying to connect more than two networks together. For example, a "four branch offices require six lines to directly connect them to each other, six branch offices need 15 lines, and so on"

(Mitchell, n.d.b).

Today's consumer DSL and cable modems offer speeds many times faster at a small fraction of the monthly costs. Using a VPN to access a company's private network is a cost effective way to leverage existing high-speed internet connections. Each client's public internet connection is used to "tunnel" to the corporate server in a secured manner.

Three practical VPN uses

Affordable high-speed internet has given rise to telecommuting options for employees either full-time or a part-time basis. This provides a company's employees with increased mobility and allows them to travel while maintaining the ability to communicate and access corporate resources.

VPNs can also provide a gateway between networks, by employing a VPN server to server connection. This type of connection is used to join two different networks together. The result is that both networks are joined together - instead of just one client.

VPNs can also be employed internally within a private network as a method of controlling access to individual subnets. This type of VPN "allows the security benefits of VPN to be deployed inside an organization. This approach has become especially popular as a way for businesses to protect their WiFi local networks" (Mitchell, n.d.b).

Limitations of a VPN

As with any technology, certain limitations should be considered when deciding to deploy this strategy within a company's network infrastructure. Exposing a corporation's private network to the internet should not be attempted unless the company possesses the appropriate human resources specially trained in network security and administration. As an alternative, companies can also look toward a service provider, such as Positive Networks, for hosted VPN solutions.

As clients connect to the VPN using their individual internet connections provided by Internet Service Providers (ISPs), the speed and reliability of the connection in are out of the company's control and may become difficult to support connection issues if a problem arises. Depending on the client application, some connections (like dial-up) may be unusable and may require a high-speed internet connection to be useable. A company should survey prospective VPN user's internet connection speeds and take this into consideration prior.

"Historically, VPN products and solutions from different vendors have not always been compatible due to issues with VPN technology standards" (Mitchell, n.d.b) but with smaller companies experiencing merger and acquisition (M&A) activity by the bigger names in network hardware solutions, this is becoming less a factor. Recent consolidations include Neoteris, which was purchased by Juniper Networks (NetScreen) in late 2003 (Juniper, 2003).

Companies like Litehouse Foods, a leading manufacturer of refrigerated salad dressings and dips, originally made a substantial investment in a Neoteris VPN solution. The company was offered a very attractive hardware upgrade, which leveraged 100% of their original investment toward an upgraded NetScreen SSL VPN solution such as the Juniper Networks Secure Access 2000.

The Juniper Networks Secure Access 2000 (SA 2000) SSL VPN enables small- to medium-sized