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Publication date: August, 2012
Revision 1.0
Welltech Technology Co., Ltd.
114
3-8.5 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.
Web Interface
To show LLDP EEE neighbors:
1. Click LLDP, then click EEE to show discover EEE devices.
2. Click Refresh for manual update web screen.
3. Click Auto-refresh for auto-update web screen.
Figure 3-8.5: The LLDP Neighbors EEE information
N
OTE
:
If your network without any devices which enables
EEE function then the table will show “No LLDP EEE
information found”.
Parameter 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
reassertion of LPI.
Rx Tw :
The link partner’s time that receiver would like the transmitter to holdoff 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.