Managing Power Over Ethernet (Poe) - Alcatel-Lucent OmniSwitch 6850E Series Hardware User's Manual

5
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 restric-
tions 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 elec-
trical 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 6850E Series Hardware Users Guide
Managing Power over
January 2013
Ethernet (PoE)
page 5-1