Dell PowerConnect 5548 User Guide - Page 384

Green Ethernet Configuration Green Ethernet is a name of a set of features that are designed to reduce the power consumption of a device, and so make it environmentally friendly. The Green Ethernet feature reduces overall power usage in the following ways: • Energy Efficient Ethernet - When using EEE, systems on both sides of the link can disable portions of their functionality and save power during periods of low link utilization. EEE is a hardware feature that is enabled by default, and is transparent to users. This feature is defined per port, regardless of their LAG membership. • Short-Reach Mode - Power usage is adjusted to the actual cable length. In this mode, the VCT (Virtual Cable Tester) length test is performed to measure cable length. If the cable is shorter than a predetermined length, the switch reduces the power used to send frames over the cable, thus saving energy. This mode is only supported on RJ45 ports. Power savings and current power consumption in Short Reach mode can be monitored. The total amount of saved energy can be viewed as a percentage of the power that would have been consumed by the physical interfaces had they not been running in Green Ethernet mode. 384 Dell PowerConnect 55xx Systems User Guide