Net as a graph: Levels 4-6

4. Nodes=IP network prefixes (SDSC: 132.249.0.0/16), links - packet seen at both (no networks in between)

5. Atoms: Nodes=groups of prefixes with equal AS paths, links - packets seen at both (no atoms in between)

6. AS: Nodes=Autonomous systems (SDSC: AS 195), links=packets seen at both (no AS in between)