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Table of Content:
General
Legality and Privacy
Downloading & Uploading files using Bittorrent
Security
Miscellaneous
General
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.
[http://dessent.net/btfaq/#what]
How does it work?
In our traditional download model (http), the Blackhole Motorsports
server sends the download data to anyone and everyone who
wants it. This system is nice and simple, but it relies on
a single server to have a connection that's fast and reliable
enough to handle all requests for the file. It also means
that Blackhole Motorsports is responsible for the cost of
every byte that's downloaded.
When BitTorrent is used to download a file, the central Blackhole
Motorsports' server is replaced by a tracker. The tracker
doesn't actually host any of the download data; it merely
maintains a list of all the clients that wish to download
the file. The clients download that list, then communicate
directly with each other. This group of clients is called
a swarm.
The clients in the swarm trade pieces of the download in
a mutually-beneficial fashion. For example, if client A has
piece #3 of the file but is missing piece #4, it might notice
that client B is missing piece #3. Client A will then send
that piece to client B in the hopes that it will return the
favour by sending back piece #4. Smart BitTorrent clients
can even figure out which other clients offer the best transfer
rates and return favours most consistently.
Okay, but if there is no central server, where does the download
data come from in the first place? The answer is that the
original source of the download file is just another client
in the swarm. Once a client finishes downloading a file, it
will continue to offer parts of the file to other clients
in the swarm. Such "completed" clients are called
seeds, and it's generally considered polite to remain in the
swarm until your client has uploaded as much data as it has
downloaded.
[http://www.sitepoint.com/newsletter/viewissue.php?id=3&issue=88&format=html#5]
Why does BlackHole
Motorsports use Bittorrent?
Bittorrent is a technology designed to solve the biggest problem
with offering downloads. Serving large files, such as mods,
movies and demos, creates problems of scaling, reliability.
Since Blackhole Motorsports has recently become more and more
popular we were faced with the following problems:
- An increase in our bandwidth costs.
- The possibility that a popular file can overwhelm our
server
To overcome these problems we decided to use Bittorrent for
our large and popular files. When Bittorrent is used to download
a file we don't have to rely on the Blackhole Motorsports
server, but instead can rely on a group of clients that wish
to download the file.
[http://www.sitepoint.com/newsletter/viewissue.php?id=3&issue=88&format=html#5]
Legality and Privacy
Is Bittorrent legal?
Bit Torrents themselves are entirely legal. However, the use
of the Bit Torrent Network to distribute copyrighted material
without the express consent of the owner is illegal. Although
Bittorrent is used for piracy purposes, but recently providers,
including Blackhole Motorsports, of large and legitimate downloads
are beginning to discover the strength of the model. For example
the Slashdot community and the Mozilla Project are using Bittorrent
Technology to distribute their files.
[http://www.sitepoint.com/newsletter/viewissue.php?id=3&issue=88&format=html#5]
Does BitTorrent maintain
my privacy?
Yes, as much as possible. The official BitTorrent client doesn't
know your name, email address, SSN or credit card number,
so it doesn't have any way to misuse the information. I suppose
the client could be written so as to steal the information
of the host computer, but because the application is open
source, someone probably would have noticed anything sneaky
like that.
[http://www.monduna.com/bt/faq.html#PRIV_1]
What personal information
is shared with other users?
If you download a bit torrent, then the tracker and other
users will know:
- Your IP Address
- That you are downloading the file
- That you were smart enough to figure out how to download
a torrent.
- That you have access to a computer and the internet.
None of these are particularly damaging pieces of information.
(You give your IP address to every web site that you visit).
However, if someone were determined enough, they might be
able to derive information about you from your IP address.
If they had legal reasons, they may even be able to force
your ISP to give them more information about you. But that
isn't going to happen, unless you're doing something massively
illegal.
[http://www.monduna.com/bt/faq.html#PRIV_2]
Downloading & Uploading files using Bittorrent
What do I need to download
the files?
You will need a Bittorrent Client. Although there are a lot
of Bittorrent clients, Blackhole Motorsports recommends the
following Bittorrent Clients:
Blackhole Motorsports recommends these clients, because they
support the so called web seeds. This means that we can use
our webserver as a bittorrent client and don't have to use
a special server for a file. You can still use other bittorrent
to download from the Blackhole Motorsports' swarm, but whenever
there are no other seeds in the swarm available you will not
be able to complete your download. If you use the clients
recommended above you will always be able to complete your
download.
How do I download files
using Bittorrent?
BitTorrent is not like other peer-to-peer applications (such
as Winmx, Kazaa, Gnutella, etc.) in that it does not have
its own "universe." Put another way, BT lives on
top of the Web, which means that all of the searching/listing
of available files is done on the web, in our case in the
download section of Blackhole Motorsports. When you find a
file you want to download, you click on it and the BitTorrent
client program will run and ask you where to put it, and then
start downloading.
[http://dessent.net/btfaq/#now_what]
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. There is no "shared directory" setting
as with other peer-to-peer applications.
[http://dessent.net/btfaq/#upload]
Why do some files
download more slowly than others?
Files may download more slowly if they are less popular, or
they are no longer popular. For example, a mod that has just
been released is going to be popular, and will probably download
very quickly. However, a torrent for a mod that has been released
3 months ago probably won't be as popular, and will download
more slowly. It may also be the case that there are other
people downloading, but they all have slow connections.
[http://www.monduna.com/bt/faq.html#SPEED_2]
Why is my download
speed so low if my upload speed is so high?
If you are one of the first people to be downloading a torrent,
or you have one of the fastest connections among people downloading
a torrent, or you are almost finished downloading a torrent,
then it is likely that your download speed will be less than
your upload speed. However, over the course of the entire
download, the download and upload speeds usually average out
to be about the same.
[http://www.monduna.com/bt/faq.html#SPEED_3]
Why does my download
speed change so frequently?
The bit torrent network is a dynamic place. If you
are downloading pieces from someone with a fast connection
and they disconnect, or run out of pieces that you don't already
have, then your download speed will change. If you run out
of pieces of the file that people are interested in, your
download speed will change.
[http://www.monduna.com/bt/faq.html#SPEED_4]
I just started downloading
the file. Why is it already so big?
When BitTorrent starts, it allocates space for the
entire file(s). That is what you see at startup as the progress
bar moves across the screen and the disk drive goes crazy.
The reason it does this is because it downloads the file in
pieces, and those pieces arrive in an arbitrary order. Unlike
http or ftp, which download the file from start to finish,
BT downloads it in random order.
Security
Is it safe to download
and share files using the Bittorrent network?
You may have heard some bad things about other P2P networks
(spyware, viruses, etc...) but, BitTorrent is totally different.
Most P2P programs install on your computer and many of the
programs for MS Windows come "bundled" with other
programs that get installed as you install the program. These
programs range from the annoying (which produce pop-up ads)
to the downright nasty (which include spyware to track your
surfing habits). Programs like iMesh, KaZaa, OverNet and others
come bundled with these "malware" programs that
run under MS Windows. BitTorrent is totally different. You
do not share any files or directories locally on your machine
(except the one that you're downloading). There are no other
program installed with the BitTorrent client under Linspire.
The only way to download a file under this P2P network is
to click on a link. There is no random sharing or shared directories.
You can only share one file at a time -- the one that you
are currently downloading.
[http://info.linspire.com/support/BitTorrent/]
I have a firewall
can I still use Bittorrent to download your files?
Yes, but you will get better performance if other peers can
connect to you. See here for detailed instructions on how
to allow incoming BitTorrent connections.
FIREWALL LINK : http://userpages.umbc.edu/~hamilton/btclientconfig.html
[http://bitconjurer.org/BitTorrent/FAQ.html]
Miscellaneous
Links
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