2 research outputs found
Delay Properties of Energy Efficient Ethernet Networks
Networking operational costs and environmental concerns have lately driven
the quest for energy efficient equipment. In wired networks, energy efficient
Ethernet (EEE) interfaces can greatly reduce power demands when compared to
regular Ethernet interfaces. Their power saving capabilities have been studied
and modeled in many research articles in the last few years, together with
their effects on traffic delay. However, to this date, all articles have
considered them in isolation instead of as part of a network of EEE interfaces.
In this paper we develop a model for the traffic delay on a network of EEE
interfaces. We prove that, whatever the network topology, the per interface
delay increment due to the power savings capabilities is bounded and, in most
scenarios, negligible. This confirms that EEE interfaces can be used in all but
the most delay constrained scenarios to save considerable amounts of power.Comment: 4 pages, 7 figure
Leveraging Energy Saving Capabilities of Current EEE Interfaces via Pre-Coalescing
The low power idle mode implemented by Energy Efficient Ethernet (EEE) allows
network interfaces to save up to 90% of their nominal energy consumption when
idling. There is an ample body of research that recommends the use of frame
coalescing algorithms---that enter the low power mode as soon as there is no
more traffic waiting to be sent, and delay the exit from this mode until there
is an acceptable amount of traffic queued---to minimize energy usage while
maintaining an acceptable performance. However, EEE capable hardware from
several manufactures delays the entrance to the low power mode for a
considerable amount of time (hysteresis). In this paper we augment existing EEE
energy models to account for the hysteresis delay and show that, using the
configuration ranges provided by manufacturers, most existing EEE networking
devices are unable to obtain significant energy savings. To improve their
energy efficiency, we propose to implement frame coalescing directly at traffic
sources, before reaching the network interface. We also derive the optimum
coalescing parameters to obtain a given target energy consumption at the EEE
device when its configuration parameters are known in advance.Comment: 25 pages, 11 figure