For you who have a router some of the ports is open and the rest is closed.
if you dont know how to open specific ports then some programs like kazaa and online games ex. Warcraft III.
1st connect to 192.168.0.1 (Routers address)
2nd enter your password and username. (Username: admin Password:1234 if you havnt changed it.)
3rd go to Advanced Setup or Advanced Features.
4th Click on Open Ports
5th Ckick on a number which have no text to the right.
7th Click Enable open ports. Write 127.0.0.1 in the Local computer textbox.
Choose Tcp on the scrolllist. Write the port number in the textbox to the right of the scrollist.
Ex 1114 - 1118 opens 1114 to 1118
Click on OK.