Black Box LPB2910A, User Manual

Page: 307 / 367

Publication date: Sept, 2015
Revision A1
295
3-­‐11.4EEE
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:
4. Click Monitor, LLDP, then click EEE to show discovered EEE devices.
5. Click Refresh to manually update the web screen.
6. Click Auto-­‐refresh to auto-­‐update the web screen.
Figure 3-­‐11.4: The LLDP Neighbors EEE information
N
OTE
: If your network does not have any devices that have the EEE
function enabled, 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 the transmit path can hold off sending data after reassertion
of LPI.

Rx Tw:
The link partner’s time that the 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