The power of shortcuts in greedy routing in content addressable networks

Abstract

In this paper, we propose a scheme to dynamically establish shortcut links in Content Addressable Networks (CAN), based on a probabilistic method suggested by Kleinberg in 2000. The proposed scheme consists of the following three steps: 1) estimation of the total number of nodes participating to the P2P system, 2) dynamic adjustment of the probability distribution for selecting the target point of shortcut based on the estimated number, and 3) the establishment of shortcut to the nodes corresponding to the selected points. The performance of the resulting scheme is evaluated by simulation. The result of simulations implies that the shortcut significantly reduces the average number of hop counts, and the rate of improvement increases as increasing the number of nodes; e.g., the proposed method improves the hop counts in conventional CAN by 49% when it contains 4096 nodes. In addition, dynamic adjustment of the probability distribution improves the performance of the overall scheme, although the amount of improvement is less than "one hop" for relatively small netwotks examined in the simulation. © Springer-Verlag Berlin Heidelberg 2004.