I use a router without UPnP
If you use a router without UPnP you will have to forward the correct port manually. To do this you will have to enter the web config page of your router (it is advised that you read your routers manual). Once you are in the web config page, go to the port forwarding section, and forward the port you chose to your local LAN IP address of the computer running BitTorrent.
Note: for this to work correctly, you must have a static LAN IP, not a LAN IP assigned by your routers DHCP.
If you don’t know what your local LAN IP is:
On the computer that will be running BitTorrent.
Click Start…Run…type “cmd”…Press OK
Then type “ipconfig”, and press Enter.
The number in the red box is the LAN IP that you forward the port to.
For step by step instructions on how to port forward on different routers, go to http://www.portforward.com/routers.htm, choose your router from this list, then click on the link that says “Port Forwarding for YOUR ROUTER”.
If you are having problems have a thorough read of the Azureus Wiki page on port forwarding.