When visualizing the Internet, one can consider several different levels of abstraction, including the Internet Protocal (IP) address, router, and Autonomous System (AS) levels. IP addresses identify interfaces on devices that connect to the Internet. Routers are devices that route traffic by accepting it on one interface and forwarding it out another interface. (Routers may have many interfaces.) An Autonomous Systems (AS) is a set of IP addresses operated under a single administrative umbrella. The three granularities are illustrated below:
Most Internet mapping methods have focused on characterizing and modeling network structure at the level of interconnected Autonomous Systems (ASes). We have developed different ways to annotate ASes, using a variety of available datasets, to support visualizations of AS topology:
I gave a class lecture at UCSD in January 2016 on visualizing Internet AS topology. I also prepared a supplemental data set to facilitate student exploration and experimentation. Comments and feedback welcome!