Free
peer-to-peer file sharing
technology enables individuals
to share files, including
music, video, or software.
Because the files do not
reside in a central location
— they are stored
on the hard drives of users
— free peer-to-peer
file sharing technology
allows for faster file transfer
and conservation of bandwidth.
Even
though many free peer-to-peer
file sharing systems have
been proposed and implemented,
only very few have stood
the test of intensive daily
use by a very large user
community. The D-tran free
peer-to-peer file sharing
system is one of these systems.
Measurements on Internet
backbones indicate that
D-tran has evolved into
one of the most popular
networks.
There are different aspects
that are important for the
acceptance of a free peer-to-peer
file sharing system by a
large user community. First,
such a system should have
a high availability. Secondly,
users should (almost) always
receive a good version of
the content they request
(no fake files) Thirdly,
the peer-to-peer file sharing
system should be able to
deal with flashcrowds. Finally,
users should obtain a relatively
high download speed.
The contributions of free
peer-to-peer file sharing
are the following: first,
we add to the understanding
of the operation of a free
peer-to-peer file sharing
system that apparently by
its user-friendliness, the
quality of the content it
delivers, and its performance,
has the right mechanisms
to attract millions of users.
Second, the results can
aid in the (mathematical)
modeling of free peer-to-peer
file sharing systems. It
is assumed that the arrival
process and the abort and
departure processes of downloaders
are Poisson, something that
is in obvious contradiction
with our measurements. One
of our main conclusions
is that within free peer-to-peer
file sharing systems a tension
exists between availability,
which is improved when there
are no global components,
and data integrity, which
benefits from centralization
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