For the current distribution of BRITE, the provided AS-level models are very similar to the models provided for generating router-level topologies. The main difference between these router-level and AS-level models is the fact that AS models place AS nodes in the plane and these have the capability of containing associated topologies. Note that this does not mean that there are no AS-level and router-level models that differ substantially from each other. The idea of separating router-level from AS-level from the beginning is to allow for the flexibility of developing independent models for each scenario. The two AS-level models provided with the initial distribution of BRITE are ASWaxman and ASBarabasiAlbert.