Open source library or class that punches through NAT/Firewalls for P2P data transfer

I'm looking for some C#/.NET library that I can use to do s开发者_JAVA百科ome NAT-Punching for multi-player game development. Using a central server to establish initial connection is OK, but ideally connections would drop into p2p mode after initial communication with server.

If you are working with P2P data transfer in .NET please take a look at Mono Torrent that's an open source implementation of the BitTorrent protocol.

You can either embed the whole Mono Torrent library and use BitTorrent as your underlying protocol or take the relevant parts of it for your own project. The library has a very liberal license (MIT/X11) that allows embedding.