Active probing techniques, such as ping, have been used to detect outages. When a previously responsive end host fails to respond to a probe, studies sometimes attempt to confirm the outage by retrying the ping or attempt to identify the location of the outage by using other tools such as traceroute. The latent problem, however, is, how long should one wait for a response to the ping? Too short a timeout risks confusing congestion or other delay with an outage. Too long a timeout may slow the process and prevent observing and diagnosing short-duration events, depending on the experiment's design.