Niveo Professional NGSME16T2H - Manual (Page 36)

Chapter 3: Featuring Configuration – Web UI
Featuring Configuration – Web UI
NGSME16T2H User Manual | 36
EEE Configuration:
This page allows the user to inspect and configure the current EEE port settings:
EEE is a power saving option that reduces the power usage when there is very low
traffic utilization (or no traffic).
EEE works by powering down circuits when there is no traffic. When a port gets data
to be transmitted all circuits are powered up. The time it takes to power up the
circuits is named wakeup time. The default wakeup time is 17 us for 1Gbit links and
30 us for other link speeds. EEE devices must agree upon the value of the wakeup
time in order to make sure that both the receiving and transmitting device has all
circuits powered up when traffic is transmitted. The devices can exchange
information about the devices wakeup time using the LLDP protocol.
For maximizing the power saving, the circuit isn't started at once transmit data are
ready for a port, but is instead queued until 3000 bytes of data are ready to be
transmitted. For not introducing a large delay in case that data less then 3000 bytes
shall be transmitted, data are always transmitted after 48 us, giving a maximum
latency of 48 us + the wakeup time.
If desired it is possible to minimize the latency for specific frames, by mapping the
frames to a specific queue (done with QOS), and then mark the queue as an urgent
queue. When an urgent queue gets data to be transmitted, the circuits will be
powered up at once and the latency will be reduced to the wakeup time.