Allied Telesis AT-GS900/8PS manual Power Over Ethernet

AT-GS900/8PS Switch Installation Guide

Power Over Ethernet

The AT-GS900/8PS switch features Power over Ethernet (PoE) only on ports 1 - 4. 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 can make it easier to install a 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. 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-GS900/8PS switch acts as a PSE unit by adding DC power to the network cable, thus functioning as a central power source for another network device.

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. PoE ports 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-GS900/8PS switch supports 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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