# Future Sustainable Internet Energy-Defined Networking
## 2 Related Work and the State of the Art  
Currently, Internet networks enable users and industrial vertical systems to minimize energy consumption; as such, they are considered \"green\". They allow services to reduce their energy footprint and become more sustainable. Future Internet networking realization will depend on significantly reducing energy consumption with very high energy efficiency for economic and social sustainability. New comprehensive methods and frameworks to make networking minimize energy consumption ought to be designed and validated without impacting networks' functionalities and efficiencies. While connectivity infrastructure has traditionally driven consumption, deploying physical and virtual resources, considered key features of Internet networks, poses a significant challenge, as they will further contribute to the already high energy needs. The latter results from the ever-increasing user traffic/compute functions/management functions/service functions that enable operators to deploy resource overprovisioning and redundancy to cope with peak demand and provide some levels of reliability. An idle network system is assumed to have an energy consumption of ~30-40% over the same system running at full capacity [2]. In addition, in typical networking devices, only roughly half of the energy consumption is associated with the data plane [2]. An idle base system typically consumes more than half of the power over the same system running at full load [3; 4]. The incremental transmission cost of additional bits (beyond the first) is much lower than sending the first as it requires powering up a device. This means a device's power consumption does not increase linearly with the volume of forwarded traffic/computational/management/service functions. Instead, it is approximated as a step function in which power consumption stays roughly the same up to a specific traffic volume, followed by a sudden jump when additional resources must be procured to support a higher traffic volume. As such, the transmission duration dominates the energy consumption, not the actual data rate. The aim of utilizing all the above design measures for future Internet energy consumption is 10% of the current Internet, with an orchestrated trade-off of data usage, resources, trust, and energy efficiency. This includes a 90% reduction in energy consumption per energy/bit. Future Internet networks aim to be fully energy-aware (i.e., currently, the networks are energy-agnostic). As such, potential solutions need to take a holistic approach that covers all physical and virtual network resources. High-energy precision services, manage  
Figure 1: An energy-functional future Internet architecture. ment, computation, and connectivity multi-domains would include energy demand and supply prediction, programmable [5] and dynamic adjustment, and the configuration [3] of resource allocation in a domain/slice for a sustainable, greener inter-service, management, computing, and connectivity system. Research on energy efficiency has mainly focused on the data plane [6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16], which is a more significant part, accounting for more than 50% [2]. The solution space revolves around routing [3; 17] and traffic engineering approaches that mainly aim to consolidate traffic on the part of the infrastructure so that some network components, such as links or even entire routers, can be put into sleep mode, e.g., [3; 18], and thus reduce the network topology. Other approaches propose adapting the traffic sending rate to conserve energy, e.g., [19], which maintains the connectivity of the network topology and does not require new routing information distribution and re-convergence. Motivated by forwarding decisions consuming the most energy among data-plane operations, some solutions have focused on circumventing table lookups by encoding the entire routing path in packet headers [20].