Appendix C: Power Over Ethernet; Poe Device Types - HP 5400zl Series Technical Overview

Appendix C: Power over Ethernet

The IEEE 802.3af standard for Power over Ethernet (PoE) enables Ethernet switches to provide power,
as well as network signals, for compliant devices over existing CAT-5 cable. Implementing devices
that support integrated PoE, such as the HP ProCurve Switch 5400zl and 3500yl series, has several
benefits:
• Lower-cost installations because a single cable provides power along with data connectivity
• No need to modify existing network cabling
• Provides a truly international standard for power distribution
• Enables remote reset and power-off capability

PoE device types

There are two types of devices that are defined for PoE implementations. The first type, called the
powered device (PD), receives power from the second type, called the power sourcing equipment or
PSE. Powered devices include any Ethernet device capable of receiving power through a data port such
as IP telephones, IP cameras, PDAs, and tablet PCs.
Power sourcing equipment, such as HP ProCurve switches with PoE support, must meet IEEE 802.3af
specifications for voltage (47 to 57 volts DC) and wattage (up to 15.4 watts), with further limitations
on the devices that receive power.
HP ProCurve switches that are PoE-enabled support both IEEE 802.3af-compliant devices as well as
some pre-802.3af standard devices.
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