The Internet can be considered as the most complex machine that mankind
ever made. No-one, not even the most talented scientist, is able to
understand all its details and predict its future behaviour. In fact the
Internet can be compared to a living organism; the backbone lines are
the arteries and the access lines the capillaries. There may be days
that the Internet feels well and is able to deliver great performance,
on other days however parts of the Internet may be broken or infected by
viruses. If this happens a `doctor' is needed to measure the Internet's
health, diagnose the problem and heal the Internet. Just as in case of
human beings, measurements should preferably be performed from the
outside, since the various organizations that `own' the Internet may not
be prepared to give others access to their monitoring infrastructure.
The term `network tomography' is used to denote such external
measurements.
In this presentation we will present some tools and techniques for
network tomography, and discuss the problems that may be solved using
network tomography.