Abstract

Access networks include modems, home gateways, and DSL Access Multiplexers (DSLAMs), and are responsible for 70-80% of total network-based energy consumption. In this talk, I take an in-depth look at the problem of greening access networks, identify root problems, and propose practical solutions for their user- and ISP -parts. On the user side, the combination of continuous light traffic and lack of alternative paths condemns gateways to being powered most of the time despite having Sleep-on-Idle (SoI) capabilities. To address this, we introduce Broadband Hitch-Hiking (BH^{2), that takes advantage of the overlap of wireless networks to aggregate user traffic in as few gateways as possible. In current urban settings BH}2 can power off 65-90% of gateways. Powering off gateways permits the remaining ones to synchronize at higher speeds due to reduced crosstalk from having fewer active lines. Our tests reveal speedup up to 25%. On the ISP side, we propose introducing simple inexpensive switches at the distribution frame for batching active lines to a subset of cards letting the remaining ones sleep. Overall, our results show an 80% energy savings margin in access networks. The combination of BH^2 and switching gets close to this margin, saving 66% on average.

Bio: Marco Canini is a postdoctoral researcher at the Networked Systems Laboratory, EPFL , Switzerland. His research focuses on computer networking with emphasis on rethinking Internet fundamentals to include power awareness and improve Internet’s energy efficiency, methods for Internet traffic classification based on application identification, and design of network monitoring applications. Another area of interest concerns improving the reliability of distributed systems, in particular the reliability of critical infrastructure such as the Internet’s inter-domain routing system. He holds a laurea degree with honors and a Ph.D. degree in Computer Science and Engineering from the University of Genoa, Italy. During his Ph.D., he was invited as a visitor to the University of Cambridge, Computer Laboratory. He also held positions at Intel Research and Google.