Discovering the Internet’s “black holes”

Katz-Bassett has been working on a project called Hubble, a system that
apparently is able to track what he refers to as information black
holes. These are situations where a path between two computers does
exist, but messages – a request to visit a Web site or an outgoing
e-mail – get lost along the way. Katz-Bassett has published a Hubble
map that enables users to monitor such black holes worldwide or simply
type in a network address to check its status.

To determine a network status, Hubble sends test messages “around
the world” to look for computers that can be reached from some but not
the entire Internet, a situation that is described as “partial
reachability”. Katz-Bassett said that short communication blips are
ignored. However, if a problem surfaces in two consecutive 15-minute
trials, it is listed as a “problem”. The research team found that more
than 7% of computers worldwide experienced this type of error at least
once during a three-week period in fall of 2007.