Cisco CCNA (200-301)Network FundamentalsMedium

A network administrator needs to provide power to a new wireless access point located in a ceiling, where no electrical outlets are readily available. The AP supports 802.3at. Which technology can be used to deliver both data and power over a single Ethernet cable?

  1. APower over Ethernet (PoE+)
  2. BFiber Optic Cable
  3. CCoaxial Cable
  4. DUSB-C Power Delivery
Show answer & explanation

Correct answer: A. Power over Ethernet (PoE+)

Power over Ethernet (PoE) allows electrical power to be transmitted along with data on Ethernet cabling. The 802.3at standard, also known as PoE+, provides up to 25.5W to the powered device, which is suitable for many modern wireless access points.

Why the other options are wrong

  • B. Fiber optic cables transmit data using light and do not carry electrical power.
  • C. Coaxial cables are typically used for cable television or older network standards (e.g., 10BASE2) and do not natively support PoE for modern APs.
  • D. USB-C Power Delivery is for USB connections, not standard Ethernet cabling.

Power over Ethernet (PoE)

PoE is a networking standard that allows electrical power to be delivered over Ethernet cables alongside data, simplifying installation of devices like IP cameras and wireless APs.

  • Eliminates the need for separate power outlets.
  • Standards include 802.3af (PoE), 802.3at (PoE+), and 802.3bt (PoE++).
  • Requires a Power Sourcing Equipment (PSE) and a Powered Device (PD).

Memory trick: Ethernet brings data, but PoE brings the power too, like a two-in-one cable!

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