title: TCP hole punching on iPhone
body: <p>I have done a bit of reading, and although I'm new to iPhone networking I was wondering if a TCP hole punch is possible for connecting two iPhones through NAT.  I also read some helpful things about uPnP and hairpinning but I'm not to familiar with those at all, so if anyone has any ideas as to whether or not this is possible.  </p>
  
  <p>My goal is to be able to connect multiple iPhones over a large range (so it may be better to switch to some type of GPSR) but for now I'm only working with two iPhones and 3G NAT Traversal seems the simplest and most reliable in theory.</p>