So what exactly is Peer-to-Peer (P2P)?
In "Always Use Protection" I talk about P2P networks like Kazaa,
but don't really go into what peer-to-peer actually means.
First, think about what happens when you connect to a web
site. You're actually connecting to a computer that hosts the web
site. That computer is called the server (because it's serving web
data) and your computer is called the client. One web server can
serve a web site to thousands or millions of clients.
Now think about what happens when you open a direct connection
on instant messenger or try to send a file. The file is on your
friend's computer, and to access that file you try to open a
connection directly to that computer. Now, that computer isn't
really a server - it's another computer just like yours. In other
words - it's a peer computer. Peer-to-peer refers to any situation
where computer connect to each other for information instead of
going to a central server.
Chapter 5 in "Always Use Protection: A Teen's Guide to
Safe Computing" explains how you can configure your firewall
to allow these types of peer to peer connections. By default most
firewalls only allow client-server connections to web servers.
So what's all the fuss about peer to peer?
Imagine, for a moment, if music downloading were completely
legal. Someone could put their music collection on a server and
invite people to download the music. But if hundreds or thousands
of people tried to download it at once, the server wouldn't be
able to handle it - especially if its connection to the Internet
So someone came up with a great idea - instead of having
everyone download songs from a server or group of servers, why not
let them download songs from each other? Each person would share
their music collection, and when you wanted a song you would go to
a server and ask for a list of people who already had the song.
Then you would start downloading from them, maybe even download
parts of the song from several computers and then stitch them
together to form the complete song. Because each of these
"peer" computers would only be sending data to a few
other computers, you wouldn't have the problem of one overworked
This is what Napster did a few years back, forming the largest
P2P network of the time. They were ultimately shut down because
the courts determined that having a central database of song
information was illegal, even if the servers did not host the
Other networks such as Kazaa work without a central database
of songs. Instead your computer seeks out other computers called
supernodes that help spread out the search to numerous
True P2P networks are very annoying to record companies
because not only is it less clear that they are violating the law,
they are much harder to shut down even if it is determined that
they are - there is no central point you can turn off.
So instead, the record industry got together through the RIAA,
and started targeting those individuals who are actually breaking
the law by distributing copyrighted material. You see, in order
for you to connect to someone else's machine, you (or rather, the
software you are using) has to know their IP address. So if a
computer is advertising that it has music available by allowing
people to connect to it, people can find out the IP address of the
computer. Because your Internet service provider knows who has
which IP addresses, it is ultimately possible to find out who you
are. This is how the RIAA tracks down the people it sues for
So you see, the "issues" that people have with P2P
aren't with the technology itself - it's with the fact that some
people are using it in an illegal manner. Many people use P2P to
exchange files with friends using instant message services, and as
long as they aren't violating a license or copyright, it's
As time goes on, you'll probably see more and more advanced
P2P technology. One example is BitTorrent (http://bitconjurer.org/BitTorrent)
which actually works faster as more people try to download a file.
Some of it will be increasingly annoying to record companies and
movie producers. Much of it will make it easier for you to work in
collaboration with others - for example: working together on a
homework report or editing video over the Internet. Either way,
P2P in some form is probably in your future.