Chapter 4: Managing Power-Over-Ethernet Devices - Cisco Linksys SFE1000P Reference Manual

Managing Power-over-Ethernet Devices
Power-over-Ethernet (PoE) provides power to devices over existing LAN cabling, without updating or
modifying the network infrastructure. Power-over-Ethernet removes the necessity of placing network
devices next to power sources.
Power-over-Ethernet can be used in the following applications:
• IP Phones
• Wireless Access Points
• IP Gateways
• PDAs
• Audio and video remote monitoring
Powered Devices are devices which receive power from the device power supplies, for example IP
phones. Powered Devices are connected to the device via Ethernet ports. Guard Band protects the
device from exceeding the maximum power level. For example, if 400W is maximum power level,
and the Guard Band is 20W, if the total system power consumption exceeds 380W no additional
PoE components can be added. The accumulated PoE components power consumption is rounded
down for display purposes, therefore remove value after decimal point.
NOTE: Due to hardware limitations, the power
measurement accuracy is 4%.

Chapter 4: Managing Power-over-Ethernet Devices

SFE1000P Gigabit Ethernet Switch Reference Guide
Chapter
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