Ping Testing
Ping is a computer network tool used to test whether a particular host is reachable
across an IP network. Ping works by sending ICMP “echo request” packets ("Ping?") to
the target host and listening for ICMP “echo response” replies (sometimes dubbed
"Pong!" as an analog from the Ping Pong table tennis sport.) Using interval timing
and response rate, ping estimates the round-trip time and packet loss (if any)
rate between hosts...[see Wikipedia]