Evolution and characteristics of the Internet Nucleus

In this paper, we apply the k-core decompostion to analyse the Autonomous System (AS) level Internet connectivity graph from JaPnuary 2006 to October 2013 and finally obtain 94 Internet Nuclei for each month. Then, we empirically study the evolution and characteristics of the Internet Nucleus and find that the size of the Internet Nucleus grows in a linear form, which is different from the exponential growth of the whole Internet. We also use edge-exchange operation to generate the randomized version network of the Internet Nucleus. Through careful comparision, it is obvious that the Internet Nucleus is a more loosely connected network than the randomized one. Other characteristics of the Internet Nucleus such as degree distribution obeying the Zipf's law and heterogeneous regional distribution of nodes are also discussed in this paper.