I want to do TCP Hole Punching (NAT Traversal) in C#. It can be done with a rendevouzs server if needed. I found http://sharpstunt.codeplex.com/ but can not get this to work. Ideally i need some method which i give a PortNumber (int) as parameter that after a call to this method is available ("Port Forwarded") at the NAT. It would be also ok if the methode just returns some port number which is then available at the NAT. Has anybody done this in C# ? Can you give me working examples for sharpstunt or something else? Thank you