Automatically accepting inbound connections with router

Question

Why is it that I have to manually tell my wireless router which computer to forward inbound connections to, but a bittorrent client is able to figure that out?

Answer 1

Your BitTorrent client most likely implements NAT traversal.

http://en.wikipedia.org/wiki/Universal_Plug_and_Play#NAT_traversal

Answer 2

If your torrent client doesn't speak UPnP or you don't want to open your router up with UPnP, you could use Port Triggering to have the router direct traffic to the IP that opened the port.

I like this more than UPnP because you are in control of the ports being opened.

http://en.wikipedia.org/wiki/Port_triggering