Allied Telesis AT-9000/12POE, AT-9000/28POE manual Power Over Ethernet

AT-9000 Gigabit Ethernet Switch Installation Guide

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.

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