Alcatel OS6850-P48 User Guide - Page 151

5 Managing Power over Ethernet (PoE) Power over Ethernet (PoE) provides inline power directly from the switch's Ethernet. Powered Devices (PDs) such as IP phones, wireless LAN stations, Ethernet hubs, and other access points can be plugged directly into the Ethernet. From these RJ-45 the devices receive both electrical power and data flow. As the feature reduces devices' dependence on conventional power sources, PoE eliminates many restrictions that traditional electrical considerations have imposed on networks. In a PoE configuration, Power Source Equipment (PSE) detects the presence of a PD and provides an electrical current that is conducted along the data cable. The PD operates using the power received via the Ethernet data cable; no connection to an additional power source (e.g., an AC wall socket) is required. Note on Terminology. There are several general terms used to describe the feature, PoE. The terms Power over Ethernet (PoE), Power over LAN (PoL), Power on LAN (PoL), and Inline Power are synonymous terms used to describe the powering of attached devices via Ethernet. For consistency, this chapter and the CLI Command Reference Guide refer to the feature as Power over Ethernet (PoE). Additional terms, such as Powered Device (PD) and Power Source Equipment (PSE) are not synonymous with PoE, but are directly related to the feature: • PD refers to any attached device that uses a PoE data cable as its only source of power. Examples include access points, such as IP telephones, Ethernet hubs, wireless LAN stations, etc. • PSE refers to power sourcing equipment, which provides power to a single link section. PSE main functions include searching the PD, optionally classifying the PD, supplying power to the link section only if the PD is detected, monitoring the power on the link section, and scaling power back to detect level when power is no longer requested or required. As the switches fully support 10/100/1000 Ethernet connectivity, you may also attach non-PD equipment, such as computer workstations, printers, servers, etc. to the PoE ports. Important. Alcatel-Lucent recommends that PoE-enabled switches with attached IP telephones should have operational power supply redundancy at all times for 911 emergency requirements. In addition, both the switch and the power supply should be plugged into an Uninterruptible Power Source (UPS). OmniSwitch 6850/6850E Series Hardware Users Guide June 2011 page 5-1