ECIS4500 series Web Management Guide R02

Command Descriptions
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2.4.70 EEE
By using EEE power savings can be achieved at the expense of traffic latency. This latency occurs due
to that the circuits EEE turn off to save power, need time to boot up before sending traffic over the link. This
time is called "wakeup time". To achieve minimal latency, devices can use LLDP to exchange information
about their respective tx and rx "wakeup time ", as a way to agree upon the minimum wakeup time they need.
This page provides an overview of EEE information exchanged by LLDP.
Object
Description
Local Port
The port on which LLDP frames are received or transmitted.
Tx Tw
The link partner's maximum time that transmit path can hold-off sending data after
deassertion of LPI.
Rx Tw
The link partner's time that receiver would like the transmitter to hold-off to allow time
for the receiver to wake from sleep.
Fallback Receive Tw
The link partner's fallback receive Tw.
A receiving link partner may inform the transmitter of an alternate desired Tw_sys_tx.
Since a receiving link partner is likely to have discrete levels for savings, this provides
the transmitter with additional information that it may use for a more efficient
allocation. Systems that do not implement this option default the value to be the same
as that of the Receive Tw_sys_tx.
Echo Tx Tw
The link partner's Echo Tx Tw value.
The respective echo values shall be defined as the local link partners reflection (echo)
of the remote link partners respective values. When a local link partner receives its
echoed values from the remote link partner it can determine whether or not the
remote link partner has received, registered and processed its most recent values.
For example, if the local link partner receives echoed parameters that do not match
the values in its local MIB, then the local link partner infers that the remote link
partners request was based on stale information.