3Com 4500 Getting Started Manual page 27

Using Power over The Switch 4500 Power over Ethernet (PoE) units can supply power to any IEEE
Ethernet 802.3af compliant device through any of its 10/100 ports 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 PoE
compliant device into one of the ports on the Switch, the Switch will supply the
power required to the device, providing that the total power budget for the
Switch would not be exceeded by doing so.
A PoE Switch combines the functionality of a standard Ethernet Switch with a
single power supply that can power multiple devices. Using a PoE Switch has the
following advantages over an unpowered network:
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The Switch supports resistor detection according to IEEE 802.3af and pre-standard
detection methods.
The Switch 4500 supports 3Com 802.3af equipment. For the latest list of
supported devices, refer to the product page on the 3Com web site at
http://www.3com.com/
For further information on Power over Ethernet, refer to the Power over Ethernet
Configuration chapter in the Configuration Guide available on 3Com's Web site.
Power over Ethernet management is available using the web interface or the
command line interface (CLI).
Connecting a Redundant Power Supply to your Switch 4500 PWR
Reduced Cabling — a PoE (802.3af) compliant device which has its power
supplied over its ethernet cable does not require a separate power supply. If,
for example, the Switch is used to connect a 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.
Increased Reliability — a device powered by a PoE Switch will be able to take
advantage of the facilities available to the Switch. The Switch can be fitted with
a redundant power supply or uninterruptible power supply, increasing its
uptime.
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