On the Energy Efficiency of Content Delivery Architectures

We examine the energy consumption of content delivery architectures, with a focus on the benefit of content centric networking (CCN) and dynamic optical bypass. For each case, we build energy models based on the energy consumption of current network equipment and devices. We further analyze the energy tradeoff among key networking resources. By optimizing the placement of content according to its popularity, CCNs achieve good scalability in energy consumption, i.e., the per-bit energy decreases as the download rate increases. The relative energy benefit from CCNs depends on numerous factors such as content popularity, equipment energy efficiency, and network topology. As such, we provide initial assessments of the operational regimes in which CCNs are advantageous. The comparison between CCN and dynamic optical bypass suggests that CCN is more energy efficient in delivering popular content while dynamic optical bypass is more energy efficient in serving less popular content.