WCF P2P over the internet

Question

Hey guys I am trying to learn how to create a P2P application in Windows Communication foundation and I have a simple test client created so far that can communicate on the Intranet just fine. That is... I can run the application multiple times on my own machine and they can all communicate to each other, and I can also put it on another machine on my home network and they can all communicate with each other.

The problem lies in when I send the application to a friend for testing. Everything works fine, it's just that the messages aren't received. It's as if nobody is there.

I've done all sorts of research on NAT edge traversal and I'm overwhelmed by the information and everywhere I look people don't seem to have solved the problem.

I hear all sorts of things about firewalls being the issue with edge traversal needing to be enabled, but I've tried all the suggestions and it still doesn't work. I've even disabled the firewalls on both machines local and remote and nothing happens still.

Could anybody provide any insight on how to effectively punch through and have these apps be able to communicate without having to do all sorts of setup procedures and manual firewall configuration(which still seem to not work)?

Answer 1

In general, there is no way to connect to a computer behind NAT without some configuration on the router that does the NATing.

What most P2P networks do in those situations is to use supernodes – computers that are not behind NAT (or that have properly configured port forwarding) that are used to help connect other computers (that are behind NAT).