Administrator Guide

80 Switch Feature Overview
lower limit is configured by the administrator. Power is not reserved until a
PD is connected to the port. The powered device may draw up to the
configured limit. LLDP-MED packets requesting power are ignored in static
mode. Do not configure the powered device to use LLDP-MED to request
power in this mode.
Dynamic Power Management
In this mode, power is allocated based upon the detected PD class signature.
Available Power = Power Limit of the Sources – Total Allocated Power
The total allocated power is calculated as the sum of the power consumed by
each port. Dynamic mode does not reserve power for the port (the port power
limit is 0). Dynamic power management ignores LLDP-MED packets sent by
the powered device. Do not configure the powered device to send LLDPMED
packets in this mode. The powered device may draw up to the detected class
plus 5%.
Class-Based Power Management
Class-based power management allocates power based on the class selected by
the detected powered device signature and LLDP-MED. The detection
method must be configured as dot3at+legacy for AF signature devices to be
detected.
Available Power = Power Limit of the Sources – Total Class Configured Power
The total class configured power is calculated as the sum of the class-based
power allocation for each port. Note that class-based power management
mode allocates the class limit for the port. The powered device may draw up
to the class maximum based upon the detected powered device signature.
The powered device need not draw all of the requested power. The
Consumed Power display from the show power inline command shows the
actual reported power draw and does not take into account the class reserved
power. Configure the powered device to send LLDP-MED packets in this
mode. It may take up to 60 seconds to power up a device in class-based
management mode because LLDP-MED packets need to be exchanged in
order to configure the desired power.