Hybrid Memory Allocation for Content-Centric Networking

In this work, we study the problem of allocating two types of memory, which have different access speed, to a set of routers in a single content-centric network. Total network delay is adopted as the performance metric. We first formulate the allocation problem and show that it is NP-hard. Then we prove that this problem is monotone submodular with a matroid constraint. Hence, we are able to derive a guaranteed (1-1/e)-approximation solution when the network is originally stable. We consider tree-structured networks with variable hierarchies under the widely used En-route caching assumption. Simulation results show that the developed algorithm performs well compared to the optimal solution, and only a limited fraction of nodes becomes hybrid regardless of the network size. To the best of our knowledge, this is the first theoretical work on quantitative analysis and algorithm development for hybrid memory allocation for contentcentric networking (CCN).