Bittorrent Tutorial

[KiraRin]

Downloading a Client

The main thing you need to download a file is a client, a program that gets you the file from the information stored on the .torrent file.

Azureus

Azureus is a java-based client, which is pretty new in BitTorrent clients.

BitTornado

Bittornado is one of the most popular clients. It is quite functional, fairly easy to use, provides a good amount of information, and is very similar in looks to the Official Client

BitComet

BitComet is a powerful, clean, fast, and easy-to-use bittorrent client. It supports simultaneous downloads, download queue, selected downloads in torrent package, fast-resume, chatting, disk cache, speed limits, port mapping, proxy, ip-filter, etc.

µtorrent

µTorrent was written with efficiency in mind. Unlike many torrent clients, it does not hog valuable system resources - typically using less than 6MB of memory, allowing you to use the computer as if it weren't there at all.

Transmission

Transmission is a free, lightweight BitTorrent client. It features a simple, intuitive interface on top on an efficient, cross-platform back-end. As easy-to-use as most Mac open-source products.

Downloading Files

BT is great because it allows huge files to be downloaded without using one person's bandwidth (meaning slow transfer rates) or a server's bandwidth (meaning it could kill a server's bandwidth if too many files are put on. It uses bandwidth from multiple sources, and all the load on the server is just that of the hosted .torrent files, which are rarely over 20 kilobytes. When you install your client of choice, it should automatically associate the .torrent name with the client, and if not, your browser will ask you what to open the file with and choose it. Quite simply, your download will start.

On this tracker you can rate the file and leave comments, and most uploaders love when comments, requests, and ratings are left at the file's page on the tracker. Keep in mind that if you are seeding and want to change a file, you'll have to wait until after you are done seeding, or copy the file(s) and change those, then delete the originals after you are finished.

Help! My Files are Slow!

This is quite easily fixed, although sometimes not. There are three main things that would cause your downloads to be slow. The first is that you haven't forwarded certain ports. We cannot tell you here how to do this, as most routers are different, but if you have more problems, just ask in the Problems/Errors section of the forum. However, if you are behind a wireless router, usually you have to access 192.168.1.1 from your browser and you can forward there. The ports you'll have to forward are 6881-6999, and this will allow greater connectivity.

The second is that your upload speed is set too low (or too high). Most times, your download speed with BitTorrent is proportional to your upload rate (meaning that if you set your upload speed real low, your download rate will also be slow). If you observe huge upload rates but little or no download rate (for example, Upload: 25.5 kbps and Download: 0 kbps), then try lowering your client's upload rate.. (The reason is that if your upload speed is set too high then it will affect your download speed, using most of your potential bandwidth to send information rather than receive it.)

The third problem, the unfixable one (besides you having a dial-up connection or something), is that there simply are not enough seeds and/or leechers to donate enough bandwidth to you, and this is especially true with older files. There is nothing you can do about it, your best bet is to leave your connection (if you can) and computer running overnight and/or throughout the day if you are out at work or school, etc. This way, you aren't killing much bandwidth (since you aren't using any additionally), and more can go to BT and your download or seeding. This also lets you seed quite a bit as well.

Another problem that is being more and more commonplace as BitTorrent becomes more popular is that of port choking. Many ISPs see the ports being used by BT and see the large amounts of bandwidth being used, and to cut costs (especially with xDSL) or to keep bandwidth available for other users (mostly with cable configurations). A simple way to get around this is change your port range from the default to something higher, in the mostly unused port numbers (49000 is a typical port of that area). Remember to forward the ports being used and that you may need to change the ports if your speeds start dropping again.

Making a Torrent

Now that you've downloaded a bit, and have some files you would like to share with the rest of the world, how do you do it?

Make Torrent 2

Make Torrent 2 is a great little program that is very easy to use (even I have managed to use it). There are instructions on the front page of how to use it.

Azureus

Open the application by going to Start >> All Programs >> Azureus >> Azureus.

To begin, go to File >> Create a Torrent.

A window will appear showing some basic options. Click on Use an external Tracker and put in the announce URL. This usually can be found on the upload page of a tracker (http://tracker.datorrents.com:6969/announce.php)

Add Multi-Tracker information to the torrent will allow you to add backup URL's incase one fails.

Add hashes for other networks (e.g. Gnutella2, eDonkey2000)will has the files so they can be used on other networks.

Choose Single file if the torrent being create is for a single file. If not, and it is more than one file, choose Directory.

The comment box is optional.

On the next page, click Browse and search for the file or directory that the torrent will be for.

In the File box, click Browse to find the where the torrent will be saved.

File(s) Size is the size of the file(s) that the torrent is being created for.

Piece Count is how many pieces the file will be sent in.

Piece Size is how large each piece will be.

In the next box, the piece size can be chosen. It is recommended to leave this at auto.

If Open the torrent for seeding when done is checked, the torrent will open automatically after it finishes hashing.

Seeding

To do this, navigate to the upload page of your tracker and where it says Upload Path, click Browse, and navigate to the actual torrent file itself and not the actual file you want to upload (for example, Heyx3 Music Champ 10_23_03.torrent, not Heyx3 Music Champ 10_23_03.mpg), enter a name for the Torrent (this is on the tracker's frontpage, so be descriptive!), and then describe it in further detail.

[KiraRin]

FAQ

What is BitTorrent?

BitTorrent is a protocol designed for transferring files. It is peer-to-peer in nature, as users connect to each other directly to send and receive portions of the file. However, there is a central server (called a tracker) which coordinates the action of all such peers. The tracker only manages connections, it does not have any knowledge of the contents of the files being distributed, and therefore a large number of users can be supported with relatively limited tracker bandwidth. The key philosophy of BitTorrent is that users should upload (transmit outbound) at the same time they are downloading (receiving inbound.) In this manner, network bandwidth is utilized as efficiently as possible. BitTorrent is designed to work better as the number of people interested in a certain file increases, in contrast to other file transfer protocols.

What do all these words mean?

Torrent
Usually this refers to the small metadata file you receive from the web server (the one that ends in .torrent.) Metadata here means that the file contains information about the data you want to download, not the data itself. This is what is sent to your computer when you click on a download link on a website. You can also save the torrent file to your local system, and then click on it to open the BitTorrent download. This is useful if you want to be able to re-open the torrent later on without having to find the link again.

Peer
A peer is another computer on the internet that you connect to and transfer data. Generally a peer does not have the complete file, otherwise it would be called a seed. Some people also refer to peers as leeches, to distinguish them from those generous folks who have completed their download and continue to leave the client running and act as a seed.

Seed
A computer that has a complete copy of a certain torrent. Once your client finishes downloading, it will remain open until you click the Finish button (or otherwise close it.) This is known as being a seed or seeding. You can also start a BT client with a complete file, and once BT has checked the file it will connect and seed the file to others. Generally, it's considered good manners to continue seeding a file after you have finished downloading, to help out others. Also, when a new torrent is posted to a tracker, someone must seed it in order for it to be available to others.

Reseed
When there are zero seeds for a given torrent (and not enough peers to have a distributed copy), then eventually all the peers will get stuck with an incomplete file, since no one in the swarm has the missing pieces. When this happens, someone with a complete file (a seed) must connect to the swarm so that those missing pieces can be transferred. This is called reseeding. Usually a request for a reseed comes with an implicit promise that the requester will leave his or her client open for some time period after finishing (to add longevity to the torrent) in return for the kind soul reseeding the file.

Swarm
The group of machines that are collectively connected for a particular file. For example, if you start a BitTorrent client and it tells you that you're connected to 10 peers and 3 seeds, then the swarm consists of you and those 13 other people.

Tracker
A server on the Internet that acts to coordinate the action of BitTorrent clients. When you open a torrent, your machine contacts the tracker and asks for a list of peers to contact. Periodically throughout the transfer, your machine will check in with the tracker, telling it how much you've downloaded and uploaded, how much you have left before finishing, and the state you're in (starting, finished download, stopping.) If a tracker is down and you try to open a torrent, you will be unable to connect. If a tracker goes down during a torrent (i.e., you have already connected at some point and are already talking to peers), you will be able to continue transferring with those peers, but no new peers will be able to contact you. Often tracker errors are temporary, so the best thing to do is just wait and leave the client open to continue trying.

Downloading
Receiving data FROM another computer.

Uploading
Sending data TO another computer.

Share Rating
If you are using the experimental client with the stats-patch, you will see a share rating displayed on the GUI panel. This is simply the ratio of your amount uploaded divided by your amount downloaded. The amounts used are for the current session only, not over the history of the file. If you achieve a share ratio of 1.0, that would mean you've uploaded as much as you've downloaded. The higher the number, the more you have contributed. If you see a share ratio of "oo", this means infinity, which will happen if you open a BT client with a complete file (i.e., you seed the file.) In this case you download nothing since you have the full file, and so anything you send will cause the ratio to reach infinity. Note: The share rating is just a number that is displayed for your convenience. It does not directly affect any aspect of the client at all. In general, out of courtesy to others you should strive to keep this ratio as high as possible, of course.

Distributed Copies
In some versions of the client, you will see the text "Connected to n seeds; also seeing n.nnn distributed copies." A seed is a machine with the complete file. However, the swarm can collectively have a complete copy (or copies) of the file, and that is what this is telling you. Referring again to the "people at a table" analogy, consider the case where the book has 10 pages, and person A has pp.1-5 and B has pp.6-10. Collectively, A and B have a complete copy of the book, even though no one person has the whole thing. In other words, even if there are no seeds, as long as there is at least one distributed copy of the file everyone can eventually get a complete file.


BitTorrent says I'm uploading, what files am I sharing? What's being sent?

Don't worry. When you are downloading a particular torrent, you are also uploading that torrent at the same time. The parts of the file(s) that you have already downloaded are uploaded to other peers. This is normal, and it's how the protocol works.

What happens if I cancel a download? How can I resume?

BitTorrent fully supports stopping and later resuming a partial download. You don't have to do anything special. If you cancel a download before it's finished, the partial download remains on your hard drive. To resume the transfer, just click on the same torrent link again and when asked where to save the file, select the same location as last time. BitTorrent will see that the file exists and check it to see how much has already been downloaded. It will then pick up where it left off the last time.

How can I change my tracker email address?

IF ABSOLUTELY NECCESSARY
- Contact a tracker moderator (dolph probably - quickest by email - milesdolphin@hotmail.com )
- Ask him/her to delete your current username - confirmation will be required that it is your account to delete.
- Remake the account with the old username and new email.
- Please don't waste our time with requests if your going to change the username as well - just make a new account!

My stats aren't updating!

We no longer track each users specific up/downloads. Watch this space as the tracker is always being worked on

If you have any further questions, please check here