  Many models have been proposed to generate Internet Autonomous System (AS)
topologies, most of which make structural assumptions about the AS graph. In
this paper we compare AS topology generation models with several observed AS
topologies. In contrast to most previous works, we avoid making assumptions
about which topological properties are important to characterize the AS
topology. Our analysis shows that, although matching degree-based properties,
the existing AS topology generation models fail to capture the complexity of
the local interconnection structure between ASs. Furthermore, we use BGP data
from multiple vantage points to show that additional measurement locations
significantly affect local structure properties, such as clustering and node
centrality. Degree-based properties, however, are not notably affected by
additional measurements locations. These observations are particularly valid in
the core. The shortcomings of AS topology generation models stems from an
underestimation of the complexity of the connectivity in the core caused by
inappropriate use of BGP data.
