Got one more question ^^ how to calcuate the ping rate in the game plz give an example :)

It's pretty simple; just send a UDP packet to a host that, when it receives that packet, sends back a response. (You could also do ICMP, but it's a little more tricky and not really an improvement). Don't use TCP; various protocol stacks, both in hosts and routers, will buffer and delay individual packets since the protocol is stream-based.

Unless of course, you want to know the TCP route time for some crazy reason ;)

There are several ways to go about it, as Sneftel explained. The usual methods are best explained here:

http://www.codewhore.com/howto1.html

-cb