Rodney Van Meter, co-teaching a class by Jun Murai, posts notes
on why Albert-László Barabási (ALB) is both right and wrong about
the Internet (it is more or less a scale-free network when considered
as a network of Autonomous Systems (AS), but contrary to ALB's assumption John Doyle and others have pointed out that the bigger nodes are not central, an AS as a node would be somewhat
difficult to take out all at once, there are both higher and lower
layer topologies that make the Internet more robust, and
the Internet's biggest problem isn't topology at all:
The most serious risks to the Internet are not to individual
"nodes" (ASes), but rather stem from the near-monocropping of
Internet infrastructure and end nodes, and the vulnerability of the
system to human error (and political/economic considerations):
Monoculture,
who would have
thought it?
For that matter, the Internet's ability to reroute has been very
useful to ameliorate topological link breaks at the physical layer,
for example undersea cables in the Mediterranean Sea twice last year.