Multiplayer matchmaking / NAT punch-through

Development Programming & Scripting Multiplayer & Networking
1

Are there any good resources on NAT punch-through / match-making?
Anything existing that already works?
(I’m OK with UE3 based resources, too)

2

did u find any solution ?

3

UPNP Plugin is reviewing. It isn’t packet relay. Adding port-mapping to NAT.