You're trying to code a network-multiplayer FPS and you don't know what the 'ping' command is/does?
...
Some reading that might be of interest:
http://www.gamedev.net/reference/articles/article712.asp
http://www.gamedev.net/reference/articles/article1138.asp
http://www.gamedev.net/reference/articles/article722.asp
http://www.blitzbasic.com/codearcs/codearcs.php?code=1593
...
Some reading that might be of interest:
http://www.gamedev.net/reference/articles/article712.asp
http://www.gamedev.net/reference/articles/article1138.asp
http://www.gamedev.net/reference/articles/article722.asp
http://www.blitzbasic.com/codearcs/codearcs.php?code=1593