Employing a WAN Emulation Appliance or WAN Emulators
To re-create WAN conditions in a lab environment, you can use a WAN emulator. A WAN emulator is a device that lets administrators simulate adverse network conditions that typically exist on a WAN or even within a LAN environment, so applications and systems can be tested under worst-case scenario conditions to predict how they will function on the production network.
Itheon’s Puranik says, “A [WAN] emulator enables a company to realistically re-create the conditions of their existing (or proposed) IT network in a safe offline environment. It is then possible to test the performance of new (or existing) applications in this replicated network, safe in the knowledge that they are not going to bring down the company’s live production network which will be hosting mission-critical applications and services.”
WAN emulators can be used to re-create and test a wide range of functions or scenarios including testing and planning prior to rolling out new equipment or applications, creating what-if or worst-case scenarios, or performing capacity planning.
Palter explains some further uses for a WAN emulation appliance. “Developers and QA teams at any company that produces software or equipment designed to run over the WAN or be managed remotely should use a WAN simulator to test the performance and stability of their product in-house under the full range of network conditions that their customers experience. Low bandwidth links to telecommuters, long latency links to remote offices, or highly congested links in developing regions can all impact the performance of network-based applications. Developers should test all of these conditions before customers complain, and it is much easier to change a few settings on a WAN emulator than to set up a large number of real WAN links for testing.”
Even geographically dispersed companies are moving to centralized, or at least regionalized, data centers. Aggregating equipment at a single site makes administration and maintenance easier, but companies need to ensure that the end users will not suffer an unacceptable loss of performance or availability of data or applications that they must communicate with across the WAN. A WAN emulator appliance is not a cheap investment, but compared with the money lost to troubleshooting and repairing a flawed implementation or the loss of productivity created by not fully testing before deployment, the investment can be quickly recovered.