With energy costs higher in recent years, many are looking at their IT systems' power usage and asking if there is any way to cut it down and reduce costs.

With regard to servers and data centers, Andreas Antonopoulos has addressed this issue in his New Data Center Strategies newsletter.

But the IEEE is also taking a look at what can be done on the networking side. Earlier this month there was a "call for interest" on energy-efficient Ethernet within the standards body.

The slides presented at the call for interest raise good points. They say the total energy consumption of network equipment is 13 terawatt hours per year, and that's not including servers, PCs and other devices that are on a network.

The presentations note that desktop-to-switch links are mostly idle, with bursts that are seconds or even hours apart. LAN link utilization, they say, is generally between 1% and 5%. Reducing link rates can save energy, but it would be good if there were a way to advertise the desire to change up to a higher speed when needed and change speed quickly, according to a presentation by Hugh Barrass of Cisco.

In other words, use a high-data-rate PHY when utilization is high, and a low-data-rate PHY when utilization is low, as Broadcom's Howard Frazier points out.

Again, this is in the very early stages, and it will be interesting what comes out of it. But if the industry can help reduce energy consumption by recognizing that not every network link needs Gigabit Ethernet (or some other high data rate) all the time, that's all to the good.

Jeff Caruso is site editor at Network World.