User's Manual

AT-9000 Gigabit Ethernet Switch Installation Guide
28
Power Over Ethernet
The AT-9000/12POE and AT-9000/28POE switches feature Power over
Ethernet (PoE) on the 10/100/1000Base-TX ports. PoE is used to supply
power to host devices over the same twisted-pair cables that carry the
network traffic.
The main advantage of PoE is that it makes it easier to install a network.
The placement of host devices is often limited by whether there are power
sources nearby. This often limits equipment placement or requires the
added time and cost of having additional electrical sources installed. But
with PoE, you can install PoE compatible devices wherever they are
needed without being concerned whether there are power sources
nearby.
A device that provides PoE to other host devices is called power sourcing
equipment (PSE). The AT-9000/12POE and AT-9000/28POE switches act
as PSE units by adding DC power to the network cable, thus functioning
as a central power source for other host devices.
A device that receives its power from a PSE is called a powered device
(PD). Examples include wireless access points, IP telephones, webcams,
and even other Ethernet switches.
The switch automatically determines whether or not a device connected to
a port is a powered device. Ports that are connected to network nodes that
are not powered devices (that is, devices that receive their power from
another power source) function as regular Ethernet ports, without PoE.
The PoE feature remains activated on the ports, but no power is delivered
to the devices.
PoE Standards The AT-9000/12POE and AT-9000/28POE switches support these PoE
standards:
 PoE (IEEE 802.3af): This standard provides up to 15.4 watts at the
switch port to support powered devices that require up to 12.95
watts.
 PoE+ (IEEE 802.3at): This standard provides up to 30.0 watts at
the switch port to support powered devices that require up to 25.5
watts.