Allocation of PoE Power to Devices

The S-Series firmware determines the power available in the SSA for PoE based on power supply status and power supply redundancy mode. The system calculates and reserves the correct amount of power required by the SSA and then makes the balance of power available for PoE. When any change is made to the power supply status or redundancy mode, the firmware recalculates the power available for PoE.

The power available for PoE is distributed based on the configured allocation mode:

• Automatic mode (default), in which available power is distributed evenly. Any change in available power, due to a change in power supply status or redundancy mode, will trigger an automatic redistribution of power.
• Manual mode, in which the power budget is manually configured, using either CLI commands or the MIBs. The wattage configured cannot exceed the total power available on the switch for PoE.

  The configured wattage assignment is used to calculate the total available PoE power. If the total available PoE power changes, available power will be redistributed based on the calculated percentages.

If the PoE power needed or requested exceeds the power available, the system generates an SNMP trap to notify the system manager.

For more information on configuring allocation mode, see the S-, K-, and 7100 Series CLI Reference Guide.