Central placement of storage servers in tree-like content delivery networks

In this paper we consider several problems regarding the optimal placement of storage servers in content delivery networks with tree-like topologies (paths, trees and cacti). We present several novel algorithmic solutions for locating (k+p)-centers and connected k-centers (and k-medians) in these networks, both in the continuous and the discrete cases. We comment both on the theoretical and the practical efficiency of the proposed algorithms.