HP ProCurve 2520 Terminology, Related Publications

Power Over Ethernet (PoE) Operation

Overview

Related Publications

This chapter introduces general PoE operation, PoE configuration and monitoring commands, and event log messages related to PoE operation on the HP ProCurve Series 2520 and 2520G switches. The following two manuals provide further information:

■For information on installation, refer to the HP ProCurve Series 2520 Switches Installation and Reference Guide provided with the switch.

■To help you plan and implement a PoE system in your network, refer to the PoE Planning and Implementation Guide, which is available from the ProCurve website at www.procurve.com. (Click on Support, then Manuals.)

Terminology

The following PoE terms and concepts are used in this manual.

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 where the switch 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 on the switch becomes
	oversubscribed.
EPS	External Power Supply. An EPS device provides power to provision PoE ports on a switch.
	See also “RPS” below.
Oversubscribed	The state where there are more PDs requesting PoE power than can be accommodated.
MPS	Maintenance Power Signature; the signal a PD sends to the switch to indicate that the PD
	is connected and requires power. Refer to Figure 11-6 on page 19.
PD	Powered Device. A device that receives power through a direct connection to a 10/100
	Base-TX PoE RJ-45 port on the switch. Examples of PDs include Voice-over-IP (VoIP)
	telephones, wireless access points, and remote video cameras.
PoE	Power-Over-Ethernet; the method by which PDs receive power from a PoE module
	(operates according to the IEEE 802.3af standard). Some pre-standard PoE devices are also
	supported; refer to the FAQs for your switch model.
port-number	Refers to the type of power prioritization where, within a priority class, the switch assigns
priority	the highest priority to the lowest-numbered port, the second-highest priority to the second
	lowest-numbered port, and so-on. Note that power priority rules apply only if PoE
	provisioning on the switch becomes oversubscribed.

11-4