March 05, 2005

I love Bittorrent

     What more need I say? Bittorrent is probably one of the most amazingly clever pieces of software to ever come out. There is a lot of good things about bittorrent, and also several dowsides, but overall it just plain kicks ass. So what is bittorrent you ask? Well, allow me to enlighten you:
     Bittorrent is another one of those scary-sounding P2P (peer to peer) apps you keep hearing about on the news and from your friends. But this one is different. Normally, the way a P2P application works is that there is a centralized network or node that keeps track of everyone on the application. When you search for a file, you connect to everyone (or as many people as your application allows) and see if they have a file that matches your search criteria. If anyone has it, your application logs their ip address and the name, size, etc. Then when you download it you connect directly to that person and download it. Though the downloading process was basically the same as it is for downloading files from a website. The only difference is that you connect to multiple people and download from all of them at the same time, but it is still linear downloading (you can only download the each part one after the other, like counting! 1, 2, 3., etc). This is where bittorrent is really different.
     Bittorrent is different in a lot of ways from this general structure of P2P apps. The first difference is the centralized node: Bittorrent has none. The way that bittorrent works is that people have the ability to make their own node called a "tracker." A tracker is just a place that stores all the information about a file. So let's say I wanted to download a new episode of an anime I was keeping up with, here's the general process:
1) I go to an anime torrent website like
2) I find the particular anime I'm looking for.
3) I download the file known as a "torrent"
4) I open the torrent and choose where to save it.
5) This is where the process gets to the tracker! It tells the tracker some information about who I am and what I'm doing. This information is something along the lines of: My IP address, the port that bittorrent uses (where the people connect to you), and the file I'm downloading.
6) The file starts downloading, but not linearly (it's something akin to me telling you to count to 10 and you doing this: 3, 6, 7, 1, 5, 10, 2, 4, 9, 8. While you can see that all the numbers between 1 and 10 are there, I didn't do what you expected me to). In fact, what it does is it downloads the least common part, and starts offering it to other people. Wow... that all sounded very confusing, let me try and explain it a little better.
So, person A wants to give a file to a bunch of people. So he takes his file, and puts it on a tracker. And thus we begin.

Person A: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Person B: , , , , , , , , ,
Person C: , , , , , , , , ,
So both person B and C want person A's file.

Person A: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Person B: 1, , , , , , , , , Downloaded part 1 from A
Person C: , , , , 5, , , , , Downloaded part 5 from A
So since person A was the only person with any piece of the file, both person B and C downloaded from person A

Person A: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Person B: 1, , , , 5, , 7, , , Downloaded part 7 from A and part 5 from C
Person C: 1, 2, , , 5, , , , , Downloaded part 2 from A and part 1 from B
Since both person A and B had a part that the other one needed, they downloaded the parts from each other, as well as additional parts from A.

Person A: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Person B: 1, 2, , 4, 5, , 7, , , Downloaded part 4 from A and part 2 from C
Person C: 1, 2, , , 5, , 7, , , 10 Downloaded part 10 from A and part 7 from B
Person D: , , , , , , , , ,
Same process as the last time, but now we add person D to the equation, he has a whole bunch of options from where to dowload from!

Person A: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Person B: 1, 2, , 4, 5, , 7, 8, , 10 Downloaded part 8 from A and part 10 from C
Person C: 1, 2, , 4, 5, 6, 7, , , 10 Downloaded part 6 from A and part 4 from B
Person D: , , 3, , , , , , 9, Downloaded part 3 from A and part 9 from A
Now the web is expanding, and download options increase, the load on each machine decreases.

Person A: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Person B: 1, 2, , 4, 5, 6, 7, 8, 9, 10 Downloaded part 6 from C and part 9 from D
Person C: 1, 2, 3, 4, 5, 6, 7, 8, , 10 Downloaded part 8 from B and part 3 from D
Person D: 1, , 3, , , 6, 7, , 9, Downloaded part 6 from C and part 7 from A
If you don't get the general idea by now I don't know how else to convey it. It makes a web where people transfer parts in non-linear downloads, allowing for fast, reliable downloads of large to enormous files.
7) The final step! The person finishes downloading the file, but because they are kind and wonderful people they leave bittorrent open. The reason this makes them kind and wonderful people is because this means that anyone can download ANY PART from that person, at no real benefit to that person.

     So that's the way bittorrent works and why I love it. If you want bittorrent I'd suggest downloading azureus. The one challenge that makes bittorrent hard to install is that you have to open up a port on your router to the computer you are using. This isn't nessecary for everyone, but for most people who have a router in their house it may be. I'm not gonna put up instructions because if you messed up somehow while trying to follw them and ruined your computer you'd blame me and get all pissy. So if you want it you can get it, but I'm not gonna help!

Posted by Kickmyassman at March 5, 2005 11:58 PM

Is it just me, or doesn't that come with a high risk of viruses? Not only do you have to download it, but you have a chance of getting a virus from each computer, as well as the host site(I could be wrong on that) Even with the latest anti-virus software, the chances are still there. Also, I got confused at the end, but isnt this illegal. Not that it matters, but with a chance for a virus, as well of getting arrested, it doesn't strike me as a good idea. After all, anti virus software comes out after the virus. Especially when going to an anime site.

Posted by: Brian at March 6, 2005 09:22 AM

     That's one of the more clever parts of bittorrent. A file has something called a checksum, and when you have a complete uninfected file, you can use a special program to produce a checksum. What a checksum does is that it makes it so that every bit (note: bit is a size of data) in the download fits a numerical equation involving the checksum. So in a nutshell, if one person has a virus, the bit will not match and bittorrent will destroy the data and discontinue accepting data from that person.
     And now about the legality of ALL P2P apps. First of all, it is not illegal to use any P2P application. By all standards their original purpose was fine: An application designed to share files (not copyrighted ones) while not forcing an enormous amount of strain on a single computer. What is illegal is downloading and uploading copyrighted files. The reason that I point this out is because people often pick up this perception that P2P apps are banned, but if that were true then they wouldn't exist. The reason napster was sued was because the people who created the application actually also hosted music files, and therefore were actually breaking the law. The only thing fasttrack networks and gnutella networks (note: kazaa's network and limewire's network) do is just host ip addresses and offer an application to utilize these networks. So technically it's the users of the networks breaking the law, not the makers of te network. And on top of all that, the RIAA was sued (by fasttrack networks) for using kazaa-lite (and therefore violating their terms of service) to track down people offering music! AND THEY LOST. So all they can do now is host fake files that have lots of schreeching and whatnot to dissuade you from trying to download music. They can NOT ACTUALLY CATCH YOU ANYMORE. I don't actually use kazaa simply because I think it's a load of crap that normally gives you viruses and corrupted music, but oh well. And this is yet another difference between other P2P apps and Bittorrent: other P2P apps don't use checksums, so the file could be completely fake, and the P2P app wouldn't know.
     And on top of all that, Bittorrent is actually 100% legal, no strings attached. The only thing that is illegal are tracker sites that offer copyrighted materials. If you go and check, you'll notice that they have a sign saying that since Naruto was licensed in the united states, they no longer offer it. All the anime offered on Animesuki is illegal to download if you live in Japan, because it is licensed there, but 100% legal in America, because it is not internationally copyrighted yet. See why I love bittorrent so much?! GAH! It's AMAZING!

Posted by: Kit at March 6, 2005 11:39 AM

     It may also be of interest for you to know that viruses don't really infect avi files. In fact, it's really quite impossible to get a virus unless you run an infected program (this is things that do NOT NEED ANOTHER APPLICATION TO RUN, EXEs. This does not include videos, text files, etc), open an infected word document or macro, or view an infected jpeg image. People have this misconception that viruses can seep through everything to get to your computer, when the truth is that once they are on your computer, they seep into everything. Not to say you shouldn't be cautious, but there's a difference between caution and paranoia.

Posted by: Kit at March 6, 2005 11:48 AM

makes sense. Interesting. I knew about the legality issues, but I thought anime was liscensed here, making it illegal. Although I didnt know about the RIAA court case.

Posted by: Brian at March 6, 2005 08:44 PM

     Brian, you can't just "license Anime." That's the equivelant of me saying: Hey! Let's license TV! The reason copying a lot of movies is legal in most third world countries is because most third world countries don't have that specific movie licensed. But for Anime specifically...
     Anime in Japan is a hit or miss type of thing. Hundreds of series are produced each year, and as you may have noticed, we only get a few series a year. The cost of buying an international copyright license often is more then the studios who produce the series can afford. If the series does well in Japan then American companies will invest to have it translated, put into more Americanized terms, and then have voice actors speak it. They also have to invest in matching the animation mouths to match at least somewhat more accurately english speech rather then Japanese. As you can imagine, this costs huge gobs of cash that not many companies are willing to dole out, and therefore they are cautious about investing and so the licenses for most anime series stay in Japan. Which is why it's legal to download many anime.

Posted by: kit at March 6, 2005 09:15 PM
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