Visualization of Autonomous Systems (AS) inter-connections between Internet eXchange points (IX) in 2002.
Each horizontal line represents an AS. (AS labels are provided in a
larger scale image). Vertical lines connecting the AS lines and the
IX bars in the layer below show the presence of a given AS at a
given IX. ASes that are present at only one IX and do not provide
any inter-IX connections are omitted from the visualization.
Vertically, AS lines are grouped by the number of continents they connect. Those nearest to the IX layer connect IXes within a single continent. These intra-continental AS lines are colored by the color of a corresponding continent. Lines depicting ASes providing inter-continental connections are white. The more continents they connect (up to 4) the higher is their position in the image.
- IX layer Each bar represents an IX. The length of a bar is proportional to the number of ASes present at this IX (and connecting it to at least one other IX). IXes are ordered on the x axis by their longitude. When space allows, IX labels are written on their corresponding bars. Otherwise, IX labels are placed below their corresponding bar, in the label layer.
- Label layers This layer provides additional space for IX labels.
- Continent layers Continent bars are sorted on the y axis by their longitude. Horizontally, a bar spans all IXes found in a corresponding continent.
Image Data Source:
 CAIDA's skitter tool
 Packet Clearing House's Internet eXchange point data base
 K. Lougheed and Y. Rekhter., RFC 1106, "Border Gateway Protocol (BGP)"
 Meyer, D. University of Oregon Route Views Project.