Power over Ethernet (PoE) is a technology defined by IEEE standards (such as 802.3af, 802.3at, and 802.3bt) that allows network cables to carry electrical power. A PoE switch is a network switch that has this capability built-in. It detects whether a connected device is PoE-compatible and provides both data connectivity and electrical power over a single Ethernet cable. This is commonly used to power devices like wireless access points, IP cameras, and VoIP phones, eliminating the need for a separate power adapter for each device.

A. Edge router: An edge router's primary role is to forward data packets between different networks; it does not inherently supply power through network cables.

C. Access point: An access point is a device that receives power (often via PoE) to create a wireless local area network; it is a power consumer, not a supplier.

D. Patch panel: A patch panel is a passive wiring component used for cable management. It has no electronic circuitry and cannot generate or transmit electrical power.

1. IEEE Std 802.3-2018: IEEE Standard for Ethernet. Section 2

Clause 33

"Data Terminal Equipment (DTE) Power via Media Dependent Interface (MDI)

" specifies the protocol and hardware requirements for Power Sourcing Equipment (PSE)

such as a PoE switch

to deliver power over twisted-pair Ethernet cabling.

2. Cisco Systems

Inc.: "Power over Ethernet (PoE) and Power over Ethernet Plus (PoE+) on Switches

" Technology White Paper. This document states

"PoE-capable switches... can power PoE-enabled devices over the same standard cables that are used for data."

3. Kurose

J. F.

& Ross

K. W. (2021). Computer Networking: A Top-Down Approach (8th ed.). Pearson. In Chapter 6

Section 6.3.1

"Link-Layer Switches

" the text describes the functionality of network switches

with advanced models including features like Power over Ethernet (PoE) to power connected devices.