3Com 3C17203 - SuperStack 3 Switch 4400, Implementation Manual

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12
P
OWER
M
ANAGEMENT AND
C
ONTROL
This chapter outlines the use of Power over Ethernet (802.3af), explains
the benefits, and gives examples of how you can use it in your network.
Power over Ethernet and Power Management are only available on the
Switch 4400 PWR (3C17205).
What is Power over
Ethernet?
A Power over Ethernet Switch such as the Switch 4400 PWR can supply
power to compliant devices over a Category 5 or Category 5e Ethernet
cable. The same cable connects the device to the network.
Power over Ethernet is a self-configuring protocol. When you plug a
Power over Ethernet compliant device into one of the ports on the
Switch, the Switch will supply the power required by the device,
providing that the total power budget for the Switch would not be
exceeded by doing so.
Benefits of Power
over Ethernet
A Power over Ethernet Switch combines the functionality of a standard
Ethernet Switch with a single power supply that can power multiple
devices. Using a Power over Ethernet Switch has the following
advantages over an unpowered network.
Reduced Cabling
A Power over Ethernet (802.3af) compliant device which has its power
supplied over its Ethernet cable no longer requires a separate power
supply. If, for example, the Switch is used to connect the 3Com 11 Mbps
Wireless LAN Access Point 8500 to the network then only a network
cable is required to provide both power and network connectivity. Since
the Access Point is frequently wall mounted this can significantly reduce
its installation costs.