Appeal of VSAT networks expands - Technology Information

Communications News, June, 1999 by Grant Palmer

A Frame Relay back-up solution that's flexible.

When presented with an article examining new trends in the market for very small aperture terminal (VSAT) satellite networks, veteran telecom managers might expect to find an overview of new applications and reference to the large companies that have recently converted to VSAT from terrestrial alternatives such as Frame Relay. After all, VSAT providers and Frame Relay providers have engaged in a fiercely competitive battle over the past two years to capture the loyalty of telecom managers.

That's why it may be surprising to learn how some VSAT and Frame Relay providers are teaming up to offer innovative hybrid networking solutions that ensure a diverse data path for companies whose survival depends upon data integrity.

Make no mistake, worldwide demand for VSAT networks is at its highest point ever and is expected to continue growing at an annual rate of nearly 30%. By offering a single platform for interactive data, Internet, video, and audio communications at compelling economics, VSAT is still the logical networking choice for companies with more than 100 geographically dispersed sites.

But the story goes beyond VSAT's traditional territory. Now, VSAT's appeal is expanding as it emerges as an effective, flexible backup to Frame Relay networks--both for disaster recovery and as a supplement where broadcast applications, asymmetric applications, or difficult last-mile solutions are required.

ENSURING A DIVERSE DATA PATH

All terrestrial communications solutions are prone to widespread outages--due to accidentally severed cables or problems at local switching offices--and Frame Relay is no exception. This was proven in 1998, the first full year of operation for many Frame Relay networks. Few businesses can endure the three- or four-day data interruption that can result from a serious Frame Relay outage. For some businesses, such as financial services companies or retail organizations, data interruption of even a few hours can result in lost revenue. That is why the majority of Frame Relay users with high-value data have deployed, or are evaluating, back-up solutions.

Until recently, many Frame Relay users deployed ISDN or dial-up lines as back-up solutions. This often led to a rude awakening when users discovered both their primary Frame Relay service and their back-up circuits were provided by the same local exchange carriers. They found that a cut in one cable bundle could bring down their entire service package. Users quickly realized that a truly diverse data path required a back-up solution offered by a VSAT provider or a second terrestrial provider. In fact, the financial services industry has instituted new laws requiring certain banking communications to be backed up by a truly diverse data path.

A SUPERIOR BACK-UP SOLUTION

As telecom managers are bound to discover, prices rise dramatically when you try to bump the data rate on a terrestrial Frame Relay connection above 56 kbps. Raising the data rate to the next available level can triple the cost of the service. It's easy to conclude that bumping the data rate does not make economic sense, since the price hike exceeds the cost of adding a VSATback-up solution. A VSAT network can be configured with asymmetrical properties to accommodate typically heavy outbound traffic (from hub to remote site). This enables the user to effectively match the bandwidth requirements to the applications, thus avoiding the need to bump the Frame Relay network to the next highest level.

A look at the actual routing of data in a typical hybrid network reveals VSAT's inherent flexibility. In the figure, the VSAT at the remote site is connected to the router that is used for the Frame Relay network. That router will automatically route traffic to the VSAT if the Frame Relay network goes down.

The user also has the option of routing traffic to the VSAT based on traffic characteristics. Traffic that lends itself to broadcast, multicast, or batch communications can be off-loaded to the VSAT network, thereby leaving other critical response-time activities for the Frame Relay network. For example, some of the nation's largest retailers use VSAT to broadcast price file or software updates to all stores simultaneously and verify receipt. Video for business television and audio for in-store music and advertising are other examples of established broadcast applications best transmitted via VSAT.

In yet another scenario, the VSATbackup can be used to conduct diagnostics of the router and the Frame Relay network. Utilizing VSAT in this manner enables the user to diagnose Frame Relay outages independently of terrestrial networks--which are prone to suffer their own outages. It also eliminates the need to pay for a separate dial-up line for this function.

Some users in the banking industry are even using VSAT to establish redundant data centers. In this scenario, if a primary data center is disabled, VSAT can easily provide a switched backhaul from the hub station, enabling smooth data flow to the back-up data center. The alternative--commissioning of changes to a terrestrial network's private virtual circuits--is an expensive and time-consuming endeavor.