Allied Telesis AT-PC2002/POE - Manual (Page 24)

Chapter 1: Overview
24
Power over Ethernet
The twisted pair port on the AT-PC2002/POE Media Converter features
Power over Ethernet (PoE), which is a mechanism for supplying power to
a network device over the same twisted pair cable that is used to carry the
network traffic.
A device that receives its power over an Ethernet cable is called a
powered device (PD). Examples include wireless access points, voice
over Internet Protocol (VoIP) telephones, web cams, and unmanaged
Ethernet switches.
One of the advantages of PoE is that the AT-PC2002/POE Media
Converter acts as the power source for the powered device. If you add an
uninterruptible power source (UPS) to the media converter, you protect
both the media converter and the powered device from possible power
source problems, thereby increasing the reliability of your network.
PoE can also simplify network installation. A frequent issue often
encountered when selecting a location for a network device is whether
there is a power source nearby. This often limits equipment placement or
requires the added time and cost of installing additional electrical sources.
But with PoE, you can install PoE-compatible network equipment
wherever needed.
The media converter automatically determines whether or not a device
connected to the twisted pair port is a powered device. A powered device
has a signature resistor or capacitor that the media converter can detect
over the Ethernet cabling. If the resistor or capacitor is present, the media
converter assumes that the device is a powered device.
The twisted pair port on the AT-PC2002/POE Media Converter can supply
up to 15.4 watts of power to a powered device, while at the same time
furnishing standard 10/100/1000 Mbps Ethernet functionality. If the twisted
pair port is connected to a network node that is not a powered device, it
functions as a regular Ethernet port without PoE. The PoE feature remains
available on the port but no power is delivered to the device.
The AT-PC2002/POE Media Converter smart power management
functionality supports the IEEE 802.3af powered device classes listed in
Table 2.