Opera

To ensure optimal transfer speed with the BitTorrent client in Opera, you will need to make sure that Opera's BitTorrent Listen Port is connectable from the outside. The default listen port is 18768 (TCP), but this value can be changed in opera:config#BitTorrent|ListenPort.

Making sure the port is connectable from the outside normally requires two steps:

1. Configure your router to forward traffic to the Listen Port to your computer. How to do this varies greatly between router manufacturers, but there are several good resources on the Internet. A good starting point to set up port forwarding on your router is PortForward.com.
2. Make sure your firewall or Internet security software allows traffic to the BitTorrent Listen Port. If you don't know how to do this, ask your network administrator.