8-5
Link Layer Discovery Protocol (LLDP)
Energy Efficient Ethernet
Energy Efficient Ethernet
EEE (Energy Efficient Ethernet) is designed to save power by turning off network ports that are not
passing traffic. EEE includes a mechanism to awaken the port when it needs to send or receive traffic.
The transmitter sends LPI (low power idle) signals instead of the normal idle signals to indicate that
the EEE protocol is in effect. After a period of time called Ts (time to sleep), the transmitter stops
sending signals and the link is quiet. When the transmitter needs to send traffic, it begins sending normal
idle signals. After a period of time called Tw (time to wake), the link becomes active and begins passing
traffic. Ts and Tw are negotiated between the link partners using LLDP.
To display the EEE page, click LLDP > EEE in the navigation pane. EEE activated columns show if the
switch and the link partner have agreed upon which wakeup times to use.
Figure 8-4. LLDP Neighbors EEE Information Page
Table 8-4. LLDP Neighbors EEE Information Fields
Field Description
Local Port The port on which LLDP frames are received or transmitted.
Tx Tw The time in microseconds that the transmitting link partner waits after leaving the low
power idle mode, before sending data.
Rx Tw The time in microseconds that the receiving link partner requests the transmitting link
partner to wait after leaving the low power idle mode, before sending data.
Fallback Receive Tw An alternate value for the time that the receiving link partner requests the transmitting link
partner to wait after leaving LPI mode, before sending data.
Echo Tx Tw Echo sent to the link partner of the latest values received from the link partner.
Echo Rx Tw Echo sent to the link partner of the latest values received from the link partner.
Resolved Tx Tw The current Tx Tw value in use.
Resolved Rx Tw The current Rx Tw value in use.
EEE Status Status of the Energy Efficient Ethernet.
Activated—Switch and link partner have agreed upon wakeup time.
Not Activated—Switch and link partner have not agreed upon wakeup time.
To Next Page
Loading...
Need help?
General
