title: How does Skype work without port forwarding?
body: <p>I am designing a <strong>p2p</strong> application which works on port 30000. My router is not <strong>UPnP</strong> so I required to forward a port to router. But <strong>Skype</strong> a another p2p application <strong>works without port forwarding</strong> on my pc. When I analyzed it with wireshark I found its using UDP port 48980, 58544. I am using c++. </p>
  
  <p>There is a library in python <a href="http://blog.yimingliu.com/2008/01/07/nat-pmp-client-library-for-python/" rel="noreferrer">here</a> which does it for <strong>Nat PnP routers</strong>. Is it possible to programmatically forward port to router <strong>irrespective of type of router and operating system</strong>. What should be the approach to do it in c++ or any other language.</p>