If you're running Windows, click Start then run and type cmd.exe then click OK. Once the box comes up, type "ping gtplanet.net" (without the " ") and you'll receive a result like this:
Code:
ping gtplanet.net
Pinging gtplanet.net [208.122.38.66] with 32 bytes of data:
Reply from 208.122.38.66: bytes=32 time=72ms TTL=47
Reply from 208.122.38.66: bytes=32 time=79ms TTL=47
Reply from 208.122.38.66: bytes=32 time=74ms TTL=47
Reply from 208.122.38.66: bytes=32 time=73ms TTL=47
Ping statistics for 208.122.38.66:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 72ms, Maximum = 79ms, Average = 74ms
The ping time is how long it takes a request to go from your computer to, in this case, GTP's web server and back. Naturally, the lower the better.