c# peer-to-peer networking - getting around routers

c#, networking, p2p

Solution

In addition to John Feminella's answer, you might consider using the UPNP service which many consumer network devices support.

Problem

I want to code a peer-to-peer like chat program in C#. I am trying to figure out how the networking would work. I know that the concept is that each peer is a client and a server at the same time. It can connect and be connected to. But my question is, how do you connect to a computer behind a router without the port being forwarded to that computer? I know things like Bittorrent do this with no problem. I was planning on using a tracker to keep a list of peers and the ports they listen on, but I still don't understand how to get through the router issue. Could someone please explain?

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