Sunday, October 19, 2008

Analyzing and Modeling the IPv6 Internet AS-level Topology

After analyzing the topology data from CAIDA’s Scamper and our IPv6 topology discovery system Dolphin, we find that the IPv6 Internet is also scale-free at AS level but with a new feature: its exponent of the degree distribution is just 1.2, which is much smaller than that of the IPv4 Internet and those of most other scale-free networks. The value of 2 of the degree exponent is the lower bound for most scale-free networks. We argue that the degree exponent is a measure of uniformity of the degree distribution and try to seek the reason for the small degree exponent of the IPv6 Internet. Current evolving network models, however, have difficulties in reproducing such a small exponent. Then based on the two major factors affecting the exponent and the EBA model we propose a new model which has the capability to construct a scale-free network with the degree exponent smaller than 2. To verify the validity of this model, both theoretical and experimental analyses have been carried out. Finally, we demonstrate the effectiveness of this model by successfully reproducing the topology of the IPv6 Internet.

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