How to Curb Network Energy Consumption

Speaker:        Dr. Marco Canini
                EPFL, Switzerland

Title:          "How to Curb Network Energy Consumption"

Date:           Monday, 24 October 2011

Time:           4:00pm - 5:00pm

Venue:          Lecture Theatre F (near lifts 25/26), HKUST

Abstract:

In this talk, I take an in-depth look at the problem of reducing the
energy consumption of the Internet.

First, looking at the energy breakdown, I will concentrate on greening
access networks. These include mode ms, home gateways, and DSL Access
Multiplexers (DSLAMs), and are responsible for 70-80% of total
network-based energy consumption. On the user side of access networks, the
presence of continuous light traffic 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. 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.

Second, I will focus on backbone and datacenter networks. Their energy
consumption is a problem because, despite being smaller than for access
networks, it is already sufficiently large to threaten to shortly hit the
power delivery limits while the hardware is trying to sustain
ever-increasing traffic requirements. Unfortunately, existing approaches
that recompute the optimal network configuration with each substantial
change in traffic demand do not scale. To overcome the
optimality-scalability trade-off, I introduce REsPoNse, an approach that
precomputes a few energy-critical paths and uses online traffic
engineering to redirect the traffic in a way that enables large parts of
the network to enter a low-power state. Evaluation results with real
traces demonstrate that it achieves the same energy savings as the
existing approaches, with marginal impact on network scalability.

References:
- Insomnia in the Access or How to Curb Access Network Related Energy
Consumption. In Proceedings of ACM SIGCOMM'11, Aug 2011.
- Identifying and Using Energy-Critical Paths. In Proceedings of ACM
CoNEXT'11, Dec 2011 (To appear).


****************
Biography:

Marco Canini is a postdoctoral researcher at EPFL, Switzerland. His
research focuses on computer networking with emphasis on making the
Internet energy-aware, methods for traffic classification based on
application identification, and design of network monitoring applications.
Another area of interest concerns increasing the reliability of Open Flow
networks and 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.