OPTICAL SYSTEMS DESIGN
DOC ID: 10118101
OSD2512 OPERATOR MANUAL
PAGE 47
EEE works for ports in auto-negotiation mode, where the port is negotiated to either
1G or 100 Mbit full duplex mode.
For ports that are not EEE-capable the corresponding EEE checkboxes are grayed out
and thus impossible to enable EEE for.
When a port is powered down for saving power, outgoing traffic is stored in a buffer
until the port is powered up again. Because there are some overhead in turning the
port down and up, more power can be saved if the traffic can be buffered up until a
large burst of traffic can be transmitted. Buffering traffic will give some latency in the
traffic.
The switch can be set to optimize EEE for either best power saving or least traffic
latency.
PORT CONFIGURATION
Port
The switch port number of the logical port.
ActiPHY
Link down power savings enabled.
ActiPHY works by lowering the power for a port when there is no link. The port is power up
for short moment in order to determine if cable is inserted.
PerfectReach
Cable length power savings enabled.
PerfectReach works by determining the cable length and lowering the power for ports with
short cables.
EEE
Controls whether EEE is enabled for this switch port.
For maximizing power savings, the circuit isn't started at once transmit data is ready for a port,
but is instead queued until a burst of data is ready to be transmitted. This will give some traffic
latency.
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.
EEE Urgent Queues
Queues set will activate transmission of frames as soon as data is available. Otherwise the
queue will postpone transmission until a burst of frames can be transmitted.
