Application renting - A tricky decision

Renting strategic business applications from application service providers (ASP) can be a boon for network planners trying to keep pace with growing demands on IT. For many, ASP services are becoming an attractive option. But tread carefully before making any moves in this direction.

The good news for customers is that today's application-delivery technology is quite sound and supports most transport media. The industry-leading MetaFrame application server and Independent Computing Architecture (ICA) protocol from Citrix Systems delivers most Windows desktop applications with high quality using modest bandwidth. Word processors, e-mail, spreadsheets, databases and almost any data-entry application relying on a graphical user interface work effectively in this environment, even at dial-up speeds.

Better yet, ICA delivery mechanism is robust in the face of common network impediments, such as latency and packet loss. In laboratory tests with round-trip latencies of 200 msec and packet losses as high as 10%, Tolly Research observed almost no degradation in application performance or increases in required bandwidth. Achieving this level of resiliency should comfort application renters, even if they are relying on the public Internet as part of their delivery network.

The bad news when outsourcing applications is that first-blush assumptions do not apply across the board. The same robust, bandwidth-saving environment that works well for office-style applications can eat up a T-1 if graphically intensive, interactive applications are served. In addition to stealing bandwidth from other applications, programs with dynamic graphical content rapidly bog down and become ineffective on a congested network.

Users can avoid many potential ASP gotchas with some straightforward analysis and planning. Basic preparation should include the following:

Spend time defining requirements (which applications, application priorities and local storage, file transfer and remote printing needs) and projecting growth.

Benchmark performance and bandwidth requirements for critical applications. Ask a potential service provider for a test drive and monitor performance and bandwidth consumption.

Estimate total bandwidth requirements (including growth requirements) and plan to provision accordingly.

Narrow ASP selection to those firms that can properly control session traffic, insuring that mission-critical applications function properly. Make sure service providers back up their claims through enforcement of guaranteed bandwidth, latency and packet-loss levels in their service-level agreements.

Understanding the strengths and limitations of outsourcing applications before committing to an ASP strategy will save you time, money and many trips to the medicine cabinet for extra-strength pain reliever.