For example, the location of servers may be dependent on your analysis, so you'll have to walk complete this step before you can place them. Estimate how frequently each of these events is likely to occur. Next, plug in values for an acceptable duration for the event. These values may be dictated by the limits of the application itself, or by a user's expected service level. The exact limits depend on the protocol and applications.
Nothing beats a slow-link test bed.
A sample network for testing is the fastest way to determine what application performance will really be like. It's the place to try out new applications before they get deployed. It should be used by application developers and commercial software installation teams. You can set up a simple test bed using a pair of routers, using a null modem cable between serial ports. A word of caution is in order.