One way to test the reachability of a host on the internet is to “ping” the IP address of the host or the hostname (i.e. http://www.google.com). When you perform a ping, it measures the round-trip time for the message to be echoed back to your computer.
A nice little utility, with a GUI, is PingInfoView by NirSoft. PingInfoView is a small utility that allows you to easily ping multiple host names and IP addresses, and watch the result in one table. It automatically pings to all hosts every number of seconds that you specify, and displays the number of successful and failed pings, as well as the average ping time. You can also save the ping result into text/html/xml file, or copy it to the clipboard.