Allied Telesis AT-8100L/8POE User Manual

Page of 116
Stand-alone Switch Installation Guide for 8100L and 8100S Series Switches
41
Power Over Ethernet
The AT-8100L/8POE, AT-8100L/8POE-E, AT-8100S/24POE, and 
AT-8100S/48POE Switches feature Power over Ethernet (PoE) on the 10/
100Base-TX ports. PoE is used to supply power to network 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 network 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 having to worry about whether there are power sources 
nearby.
A device that provides PoE to other network devices is referred to as 
power sourcing equipment (PSE). The AT-8100L/8POE, 
AT-8100L/8POE-E, AT-8100S/24POE, and AT-8100S/48POE Switches 
act as PSE units by adding DC power to the network cable, thus 
functioning as a central power source for other network devices.
Devices that receive their power from a PSE are called powered devices 
(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-8100L/8POE, AT-8100L/8POE-E, AT-8100S/24POE, and 
AT-8100S/48POE 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.