Thanks for all the help people, i have one more question regarding TCP.
Hopefully im not the only one getting something out of this!

Is there any way to know instantly if there is an connection that wants to connect to your computer? Lets say, if someone is connecting on port 101, is there any way you can know that someone is requesting a connection on that port? Maybe some API or something? (Netstat is to slow and it has to refresh all the time).