Influence Map
This visualization focuses on the geographic location of clients
for each anycast instance. We represent each DNS root server
with a pair of maps, both of which project the world as viewed
from the North Pole.
We locate the server nodes (anycast instances) at their "center
of influence." To determine this location, we consider each
of a server's clients as a point with mass 1, then we use those
client locations to compute the centroid. Thus, anycast root
nodes that serve a primarily local clientele remain closer to
their actual geographic locations while nodes that tend to
serve a more geographically distant client set get displaced
on our maps toward the regions where they have the most clients.
In both maps, the location of each node reflects the centroid
(center of influence) of its clients geographic locations
not the actual geographic location of the server.
Displacement Map (smaller map)
For servers whose actual location and centroid differ visually,
the smaller maps show these instances' geographic displacement
using a ray (gray line) beginning at the server's actual geographic location
and ending with the node located at the centroid.
We place the label for each server on the edge of the "drift"
line, close to the server's actual projected location.
Location Map (larger map)
The larger map uses wedges to show the
relationship between each instance and its clients.
The larger map plots each server as a circle
surrounded by a group of wedges. The wedges show the relationship between
each instance and its clients. Each wedge represents the number
and average distance of clients from the instance's centroid in
the direction toward which the wedge points. Each wedge color represents
the number of clients and its length represents their average
distance. The size of the circle represents the server's total number
of clients.
Influence Maps by year
| January 10-11, 2006 |
2006 Influence Map
(.png)
(.eps )
| 
2006 Poster (.png)
(.ps version: 18x12)
|
Cooperative Association for Internet Data Analysis (CAIDA)