images show Coral's
current deployment and illustrate the clusters that Coral develops
based on network round-trip-time. These clusters allow more efficient
lookup and download: A client in New York will be directed to a Coral
proxy in the nearby tri-state area from which to download cached
files; a client in the UK is directed to a node in London.
Clients enjoy even better performance if a Coral proxy sits on a
nearby network: An NYU student will be directed to the Coral proxy on
the NYU network. And this occurs without clients being aware of
Coral or administers needing to configure anything with Coral!
The following two maps shows the 'level 1' and 'level 2' clusters that
Coral naturally forms. The level-1 national clusters ensure that
nodes within belonging to the same lookup cluster are within 60 msec
from one another, as measured by round trip times. The level-2
regional clusters ensure that nodes are within 20 msec from one
On each map, each unique cluster within the network is assigned an
alphanumeric character. We have plotted the location of our nodes by
If two nodes belong to the same
cluster, they are represented by the same character on the map. As
each PlanetLab site usually colocates several servers, the size of the
alphanumeric value expresses the number of nodes at that side that
belong to the same cluster.
Due to problems maintaining our data collection facilities, these maps
are not currently being updated. Our apologies.