Power Priority Operation - ProCurve 6200yl Management And Configuration Manual

Power Over Ethernet (PoE) Operation
General PoE Operation
11-12

Power Priority Operation

When Is Power Allocation Prioritized?
If a PSE can provide power for all connected PD demand, it does not use its
power priority settings to allocate power. However, if the PD power demand
oversubscribes the available power, then the power allocation is prioritized
to the ports that present a PD power demand. This causes the loss of power
from one or more lower-priority ports to meet the power demand on other,
higher-priority ports. This operation occurs regardless of the order in which
PDs connect to the module's PoE-enabled ports.
How Is Power Allocation Prioritized?
There are two ways that PoE power is prioritized:
Using a priority class method, a power priority of Low (the default),
■
High, or Critical is assigned to each enabled PoE port.
■ Using a port-number priority method, a lower-numbered port has
priority over a higher-numbered port within the same configured
priority class, for example, port A1 has priority over port A5 if both
are configured with High priority.
Suppose, for example, that you configure the PoE priority for a module in slot
C as shown in table 11-3.