Why is BitTorrent so hit and miss?

002According to ThePirateBay.org download page, which relates to the torrent I am trying to download, 2781 people who have successfully downloaded the file in question are sharing their connection with a further 19505 people.

But, as you can see from this…


…I am only able to connect to 8 of those peers, despite having Transmission set-up like so…

..with the bandwidth throttle set to upload at 20kbps (20kbps less than my theoretical maximum upstream).

Can anyone who knows how BitTorrent really works, tell me and everyone else how best to set up the client and why a file that has so many people sharing it can have such a poor estimated time of completion.



9 comments on “Why is BitTorrent so hit and miss?

  1. For one thing, you’re ignoring unencrypted peers. Probably like 75% of the people that use bittorrent don’t have encryption enabled.

  2. I’m not familiar with your bittorrent client (I’m Linux user) but here are a few thoughts:

    1. in the case of Azureus, it shows a big red dot if you are ‘firewalled’ and can only make limited connections. It attempts to configure my home gateway via uPnP to allow the required ports. You could place your home computer in the DMZ zone of your firewall as a temporary test.

    2. ISPs can limit the number of concurrent TCP connections you can have or other forms of bandwidth shaping.

    3. I’ve heard that Windows has a kernel hard limit on the number of TCP connections it can make. (The number of peers I can reach is usually in the hundreds on Linux) No clue on Apple.

    4. To force my client to establish connections with new peers, I occasionally set my upload speed to ‘unlimited’ for short periods (5-10 mins) then I put it back to the reasonable 50Kbs.

    5. Torrent downloads are always slow in the beginning of the download and are the fastest at the end.

    6. Some clients allow you to monitor the results of new peer connection attempts and shows messages such as ‘could not connect’, ‘timed out’ etc…

    There’s no magic (or easy) solution and really only the process of elimination is effective. e.g. try another network (friends house etc..), another bittorent client, temporarily disabling the firewall

    After configuring my client – I get 1Mb/s download fairly often but not always on a comcast connection.

    Hope this helps somewhat. Unfortunately, I’ve never come across a single shot easy solution to this.

  3. Btw, regarding unencrypted peers – I do the same. I only allow encrypted connections. Not sure about that 75% number stated above but I doubt that it’s a major factor.

    Plus, I wouldn’t jump to give up privacy for throughput.

  4. pglombardo, the bt client the OP is using is Transmission. It runs on Linux, Unix, and BSD, and I imagine any other POSIX compliant OS.

    3. I’ve heard that Windows has a kernel hard limit on the number of TCP connections it can make. (The number of peers I can reach is usually in the hundreds on Linux) No clue on Apple.

    This is not a factor here.

    To the OP:

    Raven was right. You’re ignoring unencrypted peers. I recommend starting out with no upload limit and allowing all unencrypted peers. As soon as you hit the download that you like, throttle your upload. You may or may not get the download rate you want, it depends on your connection.

  5. Yep, the router has always been the issue for me, too. I just set a static internal IP and forward the right ports appropriately. But setting the DMZ might be easier.

  6. You’ll need a greater upload speed than that. If your upstream bandwidth is 40kb/s, set it to at least 30kb/s.

    But most likely your problems are down to traffic shaping from your ISP, in which case you have few connected peers because the connections are being reset at a frantic rate by the evil shaping software.

    Who are you with?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s