11-4
Power Over Ethernet (PoE) Operation
Introduction to PoE
Introduction to PoE
PoE technology allows IP telephones, wireless LAN access points, and other
appliances to receive power and transfer data over existing ethernet LAN
cabling. For more information about PoE technology, refer to the
PoE Plan-
ning and Implementation Guide
, which is available on the ProCurve Net-
working web site at
www.procurve.com
. (Click on
technical support
, then
Product manuals (all)
).
PoE Terminology
Term
Use in this Manual
active PoE port
A PoE-enabled port connected to a PD requesting power.
priority class
Refers to the type of power prioritization that uses
Low
(the default),
High
,
and
Critical
priority assignments to determine which groups of ports will
receive power. Note that power priority rules apply only if PoE provisioning
becomes oversubscribed.
MPS
Maintenance Power Signature; the signal a PD sends to the switch to
indicate that the PD is connected and requires power.
Oversubscribed
The state where there are more PDs requesting PoE power than can be
accommodated.
PD
Powered Device. This is an IEEE 802.3af-compliant device that receives its
power through a direct connection to a Gig-T PoE port in a PoE device.
Examples of PDs include Voice-over-IP (VoIP) telephones, wireless access
points, and remote video cameras.
port-number
priority
Refers to the type of power prioritization where, within a priority class, a
PoE module assigns the highest priority to the lowest-numbered port in the
module, the second-highest priority to the second lowest-numbered port
in the module, and so on. Note that power priority rules apply only if PoE
provisioning on the module becomes oversubscribed.
PoE
Power-Over-Ethernet; the method by which PDs receive power from a PoE
module (in compliance with the IEEE 802.3af standard). Some pre-standard
PoE devices are also supported; refer to the FAQs for your switch model.
PSE
Power-Sourcing Equipment. A PSE, such as a J8702A or J8705A PoE
module installed in a ProCurve switch covered in this guide, provides
power to IEEE 802.3af-compliant PDs directly connected to the ports on
the module. The PoE module is an
endpoint
PSE.
PoE Module
Refers to a PoE Module (J8702A or J8705A) for the switches covered in
this guide.
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