Moore's Law states that data density doubles approximately every 18 months, and Metcalfe's Law says that the value of a network grows as the square of the number of users. Because these postulates have held true in practice, global enterprises have found it advantageous to embed information technology into every aspect of their operations, and the worldwide data communications services industry now generates revenue in excess of $19 billion annually, with an increasing portion derived from IP VPN services.

Despite a growing worldwide thirst for bandwidth, supply has outpaced demand by a wide margin. During the rapid expansion of the Internet in the 1990s, the data communications industry created an infrastructure that was capable of delivering cheap bandwidth in high volumes. In fact, bandwidth has become so plentiful that even the effects of Metcalfe's Law are insufficient to consume available capacity for many years to come. The result of this imbalance has been the commoditization of bandwidth, rapidly declining bandwidth prices, and a vendor environment that has actively promoted the myth that high bandwidth can address almost any performance problem.

But as enterprise application deployments have expanded to the wide area, an environment where bandwidth is sometimes as plentiful as on the LAN, IT managers have witnessed a dramatic decrease in application performance. They wonder, "Why would two networks, the LAN and the WAN, with identical bandwidth capacities, deliver such different performance results?"

The answer is that application performance is affected by many factors, associated with both network and application logic, that must be addressed in order to achieve satisfactory application performance results. At the network level, application performance is limited by high latency (the effect of physical distance), jitter, packet loss, and congestion. At the application level, performance is further limited by natural behavior of application protocols (especially when faced with latency, jitter, packet loss, and congestion at the network level), application protocols that engage in excessive handshaking across the network links, and the serialization of the applications themselves.

This white paper is intended to shed light on the issues affecting application performance in the wide area, and to give IT managers the knowledge required to design strategic enterprise application acceleration and deployment solutions.