How to use BitTorrent

I keep hearing about BitTorrent as a way to download stuff from the Internet, but I can't figure out how it works. How do I download files using BitTorrent?

BitTorrent ups the ante in peer-to-peer file sharing by distributing download and upload of files across many peers simultaneously, instead of just one peer the way traditional p2p networks work. For high demand files, you could be simultaneously downloading parts of the file from dozens of locations simultaneously. Downloading of movies and television shows tends to get most of the attention, but BitTorrent is also helping ease the download effort of open source Linux projects by offering ISO files of the latest version of an OS via Torrents. For instance, you can get Debian via BitTorrent. While opinions differ about which BitTorrent client is best for downloading files, many consider Azureus the best option. With a few tweaks to the default Azureus install you can maximize your BitTorrent experience.

Blocking Contaminated BitTorrent Seeds

Depending on what your download habits are, the first thing to do after installing Azureus is to download a plug-in called SafePeer, which blocks downloads from known contaminated sources.

Forwarding Router Ports

If your Internet connection is either a cable or DSL connection, I hope you already have a router in place to help protect your computer from external attacks. If not, get a router immediately. In combination with a software firewall, a router is a great way to help keep unwanted intruders from hacking your system. I digress.

By having a router in place you may need to forward some ports to the computer with Azureus installed to make sure you optimize your download experience. Azureus uses port 6881 by default. Many ISPs are blocking ports in the range 6881-6999, so change this on the Connection tab of Tools > Options. Switch this to a number between 49152 and 65535, which avoids ISP blockage and also prevents conflicts with applications on your system.

Once you choose a port, test it with the Gibson Research port probe by replacing the series of x's here with the port you selected: https://www.grc.com/x/portprobe=XXXXX

If the port on your system is either in Stealth mode or Closed mode, you won't get optimal download speeds from Azureus. You need to map that port number on your router to the port number on your PC in your router's settings. The process for forwarding a port varies by computer, but in general there are a similar series of steps. Linksys refers to the port forwarding page as Applications & Gaming, some other routers refer to port forwarding options as Virtual Servers.

To forward the port you defined for Azureus, you generally need to enter the following data:

Application or Description field: Azureus
Port Range Start: Port number you defined for Azureus
Port Range End: Port number you defined for Azureus
Protocol Type: Both (or TCP if a both option isn't available)
IP Address of your PC: You can find this by typing ipconfig at the command line
Enable: check a box to enable the port forward

In some cases you will also need to repeat the Port Range Start and End for the local machine (often referred to as Private Port)

For optimal security, it's a good idea to login and uncheck the Enable box when Azureus isn't in use. That way if someone happens to be scanning your ports, they won't find an opening. It's an extra step that requires only a few seconds for additional security.

In addition to opening ports on the router you also need to allow Azureus access to the Internet through your software firewall, which means adding Azureus.exe to your exceptions list (or javaw.exe for older versions)

Set Max Upload Speed

One of the primary tricks to optimizing your BitTorrent experience is managing download and upload speeds. For most cable customers the average maximum upload speed is 40-43 kbps. Azureus sets its maximum upload speed at 40, which means you could max out your upstream Internet connection without using any other connected applications. I typically set the max upload speed to 10 or 20 KB/s so that I don't need to worry about flooding my connection. Download defaults to maximum available, which almost never maxes out available speed from your ISP.