Setup Guide

The focus of this section is to help you configure BitTorrent Mainline to be able to obtain the optimal speeds for your Internet connection. While configuring it properly does not guarantee that you will hit your maximum upload and/or download speeds, it guarantees that BitTorrent Mainline is doing the best it can to get good speeds. Be sure to read this entire section if you are unfamiliar with configuring BitTorrent Mainline, because you will be expected to have read it already when asking for help elsewhere.

The Speed Guide

When you open BitTorrent Mainline for the first time, you are presented with the BitTorrent Mainline Speed Guide. As stated in the wizard, following the simple directions will help you select the optimal settings for your Internet connection.

In the first part, you are asked to select your upload speed from the dropdown menu. If you do not know the information, you can test your Internet connection speed by left-clicking on the button. On the page you are brought to, there are several mirrors listed; select the mirror closest to where you live. When you are running the speed test, make sure you are not using your Internet connection for anything besides the test. If you have any other computer on your network, disconnect them or shut them off before running the test. Run the test several times, and take the average of your upload speed given in the tests. From the "Connection Type" dropdown list, select the option closest to your average upload speed. Note that there is a distinction between bits and bytes, and speed results are generally given in kbps (kilobits per second), which should not be confused with KiB/s (kibibits per second). Additionally, the tests may not be 100% accurate due to factors outside of your control, so if the closest option is only a little bit higher than what you received on the tests (perhaps by 10%), it's generally safe to select that. If the difference is greater than that, it's best to select the lower option and manually set the correct upload speed. Do not be tempted to select an option much higher than indicated on the speed tests in hopes that it will help you download faster, as it will not, and might end being detrimental to your speeds instead.

In the second part, a port is randomly selected for you the first time the Speed Guide is displayed, though you are free to change the port used. Alternatively, setting the port to 0 indicates to BitTorrent Mainline that you would like for it to select a random port after the changes are confirmed. After you select your port, left-click "Test if port is forwarded properly" to check that the port is open. It is essential that a port is open for BitTorrent Mainline to listen for incoming connections on. If you are having trouble opening a port, continue reading onto the port forwarding guide.

When you finish configuring everything, left-click "Use Selected Settings" and you're done! If, for whatever reason, you need to return to this wizard to make a change, you'll find it accessible by selecting "Options" then "Speed Guide..." (or press Ctrl+G) in BitTorrent Mainline. Alternatively, you can left-click on the network status icon in the status bar.

Correcting Some Settings

If you found that you had to round down when selecting your connection type in the Speed Guide, you should adjust your upload speed limit to take advantage of the extra upload speed you actually have. Take the average upload speed you received when taking the test and divide it by 10, then round it to the closest whole number. Now use this calculated number as your global maximum upload rate.

Windows 95/98 users should be aware of the requirements for their operating system and either lower their global maximum number of connections to less than the MaxConnections limit, or increase that limit in the Windows Registry.

Testing Your Configuration

Because torrents don't necessarily guarantee speeds, you can't just pick any random torrent and expect to be able to test the speeds properly. Luckily, there are many torrents out there that are seeded perpetually by computers sitting on fast broadband connections. Try a test torrent to test your configuration!

When properly configured, BitTorrent Mainline should be able to attain the maximum speed possible on your Internet connection with these test torrents without much difficulty. Because these torrents are simply used for testing your connection speeds, it is safe to delete them whenever you are finished with the tests. Remember that these speeds are not indicative of how fast every torrent you come across will download.

ISP Interference

Some Internet Service Providers (ISP) block or throttle BitTorrent connections because of the high bandwidth it generates due to the sheer number of people using BitTorrent. Protocol Encryption combats this attack vector by hiding the fact that connections are BitTorrent connections. Some ISPs cannot distinguish an encrypted connection from any other random data connection, so they are unable to label it as a BitTorrent connection, and consequently, cannot block or throttle it for being a BitTorrent connection. In general, there is no harm in enabling Protocol Encryption, other than a marginal increase in peer communication overhead.

Take note that some ISPs are starting to identify even encrypted BitTorrent connections with upgraded hardware, so even Protocol Encryption might not help users getting throttled by their ISPs. For a list of ISPs known to throttle, check the Bad ISPs list on AzureusWiki. If your ISP is known to throttle or block BitTorrent traffic, then you may want to consider setting the encryption to "Forced" and disable legacy incoming connections. If that fails, then the solution would probably be to switch to an ISP that does not throttle or block.