Image Key:

• AS layer 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:

This visualization is based on the data gathered by CAIDA Macroscopic Topology Project. Our skitter tool [1] collected forward IP paths between skitter monitor hosts and a large number of target destinations. Among IP addresses seen in these paths we identified addresses belonging to IXes using the IX database maintained by Packet Clearing House [2]. For all remaining IP addresses we determined their origin ASes using BGP tables [3] from Route Views [4]. The image shows all links between IXes and ASes we found in skitter traces during the period from 2002/10/01 to 2002/10/07

click to enlarge

REFERENCES:

[1]	CAIDA's skitter tool https://www.caida.org/catalog/software/skitter
[2]	Packet Clearing House's Internet eXchange point data base https://www.pch.net/ixp/data
[3]	K. Lougheed and Y. Rekhter., RFC 1106, "Border Gateway Protocol (BGP)" http://www.ietf.org/rfc/rfc1106.txt
[4]	Meyer, D. University of Oregon Route Views Project. http://www.antc.uoregon.edu/route-views