Degree Granting Department
Computer Science and Engineering
Kenneth J. Christensen, Ph.D.
Miguel Labrador, Ph.D.
Jarred A. Ligatti, Ph.D.
Green networks, power consumption, performance evaluation, simulation, Packet Coalescing, adaptive shutdown, local area networks, LAN switches
It is estimated that networked devices consumed about 150 TWh of electricity in 2006 in the
U.S. which has cost around $15 billion and contributed about 225 billion lbs of CO
greenhouse gas emissions. About 13.5% of this energy is consumed by network equipment such
as switches and routers.
This thesis addresses the energy consumption of Ethernet, and designs and evaluates
improvements on existing methods to reduce the energy consumption of Ethernet links and
Energy Efficient Ethernet (EEE) is an emerging IEEE 802.3 standard which allows Ethernet
links to sleep when idle. In this thesis, a performance evaluation of EEE is completed. This
evaluation replicates previous work by Reviriego et al. in an independent manner. The
performance evaluation shows that EEE overhead results in less energy savings than expected. A
new method based on Packet Coalescing is developed and evaluated to improve the energy
efficiency of EEE. Packet Coalescing bursts packets such that EEE overhead is minimized. The
results show that EEE with Packet Coalescing for 10 Gb/s Ethernet can achieve very close to
ideal (or energy proportional) performance at the expense of an insignificant added per
Periodically Paused Switched Ethernet (PPSE) was previously proposed and prototyped by
Blanquicet and Christensen in 2008. PPSE uses periodically sent notification packets to halt
packet transmission into a LAN Switch and thus allowing the switch to sleep periodically. In this
thesis, a first performance evaluation of PPSE is completed. The evaluation in this thesis shows
that a PPSE for 10 Gb/s Ethernet LAN Switches achieves either significant energy savings at the
expense of an excessive packet delay, or less than expected savings with a less than human
response time added per-packet delay. An improvement to PPSE (Adaptive PPSE) is proposed
and developed based on an adaptive policy. The adaptive policy considers past traffic load to
determine whether to put the switch to sleep or not. The evaluation shows that Adaptive PPSE
can achieve very close to ideal performance at the expense of an added average per packet delay
which is less than half of the human response time.
Scholar Commons Citation
Mostowfi, Mehrgan, "Improving the Energy Efficiency of IEEE 802.3az EEE and Periodically Paused Switched Ethernet" (2010). USF Tampa Graduate Theses and Dissertations.