Delay Properties of Energy Efficient Ethernet Networks

TL;DR

This paper models the traffic delay in networks of energy efficient Ethernet interfaces, showing that power savings have minimal impact on delay across various network topologies, enabling greener networks with negligible performance loss.

Contribution

It develops a comprehensive model for delay in networks of EEE interfaces, extending prior isolated studies to network-wide analysis and proving bounded, often negligible, delay increments.

Findings

Delay increase due to EEE is bounded regardless of topology.

In most scenarios, delay impact is negligible.

EEE interfaces enable significant power savings with minimal delay penalty.

Abstract

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.