Power Allocation And Power Budget - NETGEAR GS408EPP User Manual

ProSAFE Easy-Mount 8-Port Gigabit Ethernet PoE+ Web Managed Switch

Power Allocation and Power Budget

The switch is a smart switch in that it can allocate the required power to a connected device
by using a prioritization scheme: By default, power is supplied in ascending port order (that
is, lower port numbers are served first) until the power budget is consumed and insufficient
power remains to allocate to the next device. When less than 7W of PoE power is available
on a port, the port PoE LED lights yellow, and the attached device does not receive power
from the port. However, the switch continues to send data through the port connection.
The switch is also a smart switch in that it can override the IEEE power classification of a
powered device (PD): If the PD consumes less power than required by its power
classification, the switch provides only the power that the PD consumes instead of the power
that is required by the PD's power classification.
The total available power budget for all eight PoE+ ports is 124W. If some PoE+ ports are in
use and deliver power, you can calculate the available power budget for the other PoE+ ports
by subtracting the consumed (that is, delivered power) from the total available power budget.
An example:
Port 1 delivers 4.4W to a PD. The available power budget is 119.6W (124W–4.4W).
Another example:
A Class 4 PD is attached to Port 1, a Class 2 PD to Port 2, and another Class 4 PD to Port 3.
However, the PDs consume less power than defined by their classes: The PD attached to
Port 1 consumes 7.3W, the PD attached to Port 2 consumes 4.7W, and the PD attached to
Port 3 consumes 8.9W. So even though the switch provides power to two Class 4 devices
and one Class 3 device, the available power budget is 103.1W (124W–7.3–4.7–8.9W).
To determine the delivered power by PoE+ ports:

1. Connect your computer to the same network as the switch.
You can use a WiFi or wired network connection, or connect directly to a switch that is
off-network using an Ethernet cable.
2. Launch a web browser.
3. In the address field of your web browser, enter the IP address of the switch.
If you do not know the IP address of the switch, see
Browser on page 6.
The login window opens.
4. Enter the switch's password in the password field.
The switch's default password is password.
The Switch Information page displays.
5. Select System > PoE.
Manage Power over Ethernet
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Access the Switch Using a Web