What is PoE?
PoE is the commonly used acronym for Power over Ethernet, a technology that describes a system to transfer both electrical power and data to remove devices using standard twisted-pair cable in an Ethernet network. In many circumstances, supplying power separately is infeasible, expensive, or just plain inconvenient, and a switch module that offers PoE enhances a network’s versatility and makes it more attractive to network administrators. A good comparison is POTS telephones. Like a network with PoE, POTS telephones are analog, but receiver data and power through the same cable. You may also hear PoE referred to as ‘inline power.’
Power over Ethernet is useful for powering embedded computers,wireless LAN access points,IP telephones, remote network switches, and network cameras as well as other I.T. hardware that needs power. PoE is typically implemented following the specification guidelines in IEEE std. 802.3af-2003.
A good example of the type of enhancement Power over Ethernet can provide, can be seen in WS-X4248-RJ45V by Cisco. The Cisco Systems’ WS-X4248-RJ45V is a 48-port switching module designed to deliver standards-based integrated power by expanding PoE. The Catalyst 4500 Poe offers greater mobility and flexibility to users with the support of all-new services, applications and devices. The Catalyst 4500 Series is IEEE 802.3af PoE compliant with the integration of this new line card as well as Cisco IOS Software Release 12.2(18)EW and CatOS Software Release 8.3(1)GLX. Combined, they meet the needs of commercial and enterprise customers. The WS-X4248-RJ45V is compatible with the following switches: Catalyst 4503 Switch, Catalyst 4506 Switch, Catalyst 4507R Switch, Catalyst 4510R Switch, Catalyst 4003 Switch, and Catalyst 4006 Switch.