What does Power over Ethernet (PoE) have going for it?
PoE is a seemingly innocuous innovation that will have a huge impact on the way we design, purchase, install, and manage our networking infrastructure. PoE allows us to power small network-ready devices without a separate power supply. Instead, power is provided by an "injector" (external or built into a switch) over unused wires in the Ethernet twisted pair cable.
PoE has a lot going for it including accessibility where there are no nearby AC outlets (nor the need to pay to have one installed), elimination of unsightly cords and transformers, a UPS at the injector source (one UPS on a PoE ready switch can cover dozens of devices), ease of moving access points, on so forth. With the advent of the 802.3af standard, PoE is taking off like a rocket.
There are a huge number of components available for PoE from chips to injectors to RJ-45 jacks with integrated web servers. We've only seen the tip of the iceberg for plug-n-play products. A sampling of PoE-ready devices include VoIP phones, 802.11 access points and bridges, web cams, card access systems, a clock that synchronizes to NIST and provides local time services via Telnet, and a low-power XP- based flat-panel computer.
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