Allied Telesis AT-S62 - Manual (Page 319)

AT-S62 Menus Interface User’s Guide
Section II: Advanced Operations 319
Power Over Ethernet Overview
The twisted pair ports on the AT-8524POE switch offer the same features
as the twisted pair ports on the other switches in the series. As such, they
can operate at 10 or 100 Mbps, feature Auto-Negotiation and Auto-
MDI/MDI-X, and so forth.
These ports, however, also offer Power over Ethernet (PoE). PoE is a
mechanism for supplying power to network devices over the same
twisted pair cables used to carry network traffic. This can simplify
network installation and maintenance by allowing you to use the switch
as a central power source to other network devices.
A device that receives its power over an Ethernet cable is called a
powered device. Examples can be wireless access points, IP telephones,
webcams, and even other Ethernet switches, such as the unmanaged
AT-FS705PD Ethernet switch from Allied Telesyn. A powered device
connected to a port on the switch receives both network traffic and
power over the same twisted pair cable.
There are several advantages that the PoE feature of the AT-8524POE
switch adds to the installation and maintenance of your network. First,
since the switch acts as the central power source for your powered
devices, adding a redundant power supply (RPS) or uninterruptible
power source (UPS) to the switch increases the protection not just to the
switch from possible power source problems but also to all of the
powered devices connected to it. This can increase the reliability of your
network by minimizing the impact to network operations from a power
failure.
PoE can also simplify the installation of your network. The selection of a
location for a network device is often limited by whether there is a
power source nearby. This often limits equipment placement or requires
the added time and cost of having additional electrical sources installed.
With PoE, you can install PoE-compatible devices wherever they are
needed without having to worry about whether there are power sources
nearby.
This feature requires little configuration or management. The switch
automatically determines whether a device connected to a port is a
powered device or not.
A port on the switch connected to a powered device can supply up to
15.4 watts of power to the device, while at the same time furnishing
standard 10/100 Mbps Ethernet functionality. A port connected to a
network node that is not a powered device (that is, a device that receives
its power from another power source) functions as a regular Ethernet
port, without PoE. The PoE feature remains activated on the port but no
power is delivered to the device.