Build a ping function....
PING(playerid), wait wait wait, if wait>2 seconds, KILLPLAYER()
Ping is just an instance of a small message being sent, at a specifed time.
Then it counts the time elapsed for the return reciept.
The net() functions are capable of this. Networking is quite sophisticated, and much time is needed to setup a network that functions smoothly. You will find issues, and you have the power with GLBasic to alter the functions/routines to fit the circumnstances.