Energy Efficient Ethernet

Energy Efficient Ethernet (EEE) regulates and saves power consumed by the active hardware components in the switch and conserves power during idle time.

EEE allows Brocade devices to conform to green computing standards. This functionality is achieved by moving the data ports to a low-power state when their function is not necessary or when they are in a passive, no traffic condition. The EEE feature in switching platforms reduces overall energy consumption, cooling, noise, and operating costs for energy and cooling. Lower power consumption also means lower heat dissipation and increased system stability, less energy usage, thereby reducing costs and impact on the environment.

EEE is a set of enhancements to the Ethernet specification to address power consumption during periods of low data activity. EEE is specified in IEEE Std 802.3az-2010 which is an amendment to the IEEE Std 802.3-2008 specification. The optional EEE capability combines the IEEE 802.3 Media Access Control (MAC) sublayer with a family of physical layers defined to support operation in the Low Power Idle (LPI) mode. When the LPI mode is enabled, systems on both sides of the link can save power during periods of low link utilization. LPI signaling allows the LPI client to indicate to the PHY, and to the link partner, that a break in the data stream is expected. The LPI client can then use this information to enter power-saving modes that require additional time to resume normal operation. LPI signaling also informs the LPI client when the link partner sends such an indication.