Client monitors simulate an end-to-end user experience and evaluate whether or not applications operate as expected-covering performance, accuracy and availability. This makes active monitors well suited to service target monitoring.
One useful location for active monitoring is directly in front of firewalls, covering all local infrastructure while eliminating Internet and ISP issues. This provides accurate metrics regarding optimum application performance and is often used for WAN and end-user independent service targets.
End-users use different types of modems, have different browser versions and work from diverse locations around the world. To gather response time measurements that accurately reflect end-user perspective (including Internet speed and latency) it is crucial to run the same active monitors from multiple POPs that are distributed at locations around the world. POPs should be located where the majority of end-users are located and cover all major ISPs. For globally distributed applications, or applications that are enhanced by global-caching mechanisms, POPs should be placed in such a way that all replicated application pieces are hit.