Constantinos Vassilakis

Cutting the energy bills of Internet Service Providers and telecoms through power management

The energy consumption of the Information and Communication Technology (ICT) sector has been increasing recently; this sector is estimated to account for 2% of the total energy consumption. An even more aggressively increasing trend is the volume of Internet traffic and the number of connected devices. Thus, reducing the energy needs of the Internet is recognised as one of the main challenges that the ICT sector will have to face in the near future to reduce its overall energy footprint. Introducing energy-efficient techniques, both at the device level and the network level, is required.The main goal of this work is to quantitatively evaluate the potential energy savings from applying energy-efficient techniques, while examining the trade-off between network performance and the achieved energy savings.We introduce a categorisation of the energy-aware design space, focusing on the existing techniques in the device data plane, and contribute an analytical framework to represent the impact of energy-aware technologies and solutions for network devices. Our energy profile model represents the diverse energy-aware states of the network devices and is applied over two reference scenarios, one of a large-scale Telco (Telecom Italia) and one of a medium size Internet Service Provider (GRNET), to evaluate the impact of each energy-aware technology and the energy savings potential at the Home, Access, Metro/Transport and Core parts of each network.The results show the estimates of energy savings exceed 60% in many cases, while maintaining the same quality of service as in the energy-agnostic case.

Empirical evaluation of energy saving margins in backbone networks

Fueled by concern over the energy consumption of backbone networks, lots of work has recently gone into proposals for energy-aware traffic engineering and routing. Local and network-wide policies have been developed for switching off network interfaces and concentrating traffic in as few links as allowed by SLA constraints. In this work we examine empirically the energy saving margins of such policies using extensive data from a national and a pan-European research and academic network. We analyze the dependence of such margins on several parameters, including the level of energy proportionality, QoS constraints and the geographic span of a network. Our findings reveal that with existing devices, smart powering-off can save more than 50% of currently consumed energy, and that energy-aware traffic engineering has still quite away to go before it can be made redundant by improvements in the energy proportionality of devices.

A Context Model and Policies Management Framework for Reconfigurable-by-design Distributed Applications☆

Abstract The design and development of distributed applications consisting of microservices is an emerging pattern, considering the advantages associated with the management of self-deployable and orchestratable components as well as the adoption of a DevOps culture in cloud applications deployment and management. In this position paper, we present a context model for representing the entire lifecycle of reconfigurable-by-design distributed applications consisting of microservices and denoted in the form of a service graph. Based on the context model, we describe a policies management framework targeted at service providers for managing deployment and orchestration aspects of such applications over a programmable infrastructure.