3.3.5 Power Over Ethernet

3.3.5 Power Over Ethernet Power over Ethernet (PoE) is a method of delivering electrical power from a switch port through standard data cabling to a connected powered device, such as a VoIP handset, IP camera, or wireless access point. Powering these devices via a switch is more efficient than using a separate AC adapter for each device, and it enables network management software to control the devices by implementing schemes like sleep states and power capping. PoE is defined in the IEEE 802.3-2018 standard, including 802.3af, 802.3at (PoE+), and 802.3bt (PoE++). These standards specify different power levels for various devices. PoE switches, known as endspan power sourcing equipment, detect if a device is PoE-enabled and adjust the power supply accordingly to avoid damage to non-PoE devices. Fill in the Blank: Fill in the blank with the correct words. 1. Power over Ethernet allows electrical power to be delivered from a switch port using ordinary data cabling.2. The IEEE standard for PoE that supplies power at 350mA@48V is 802.3af.3. A VoIP handset can be powered using PoE technology.4. PoE switches are also known as endspan power sourcing equipment.5. The command power inline auto max 1500 enables a port for PoE on a Cisco switch. Multiple Choice Questions: Choose the correct answer from the choices for each question. Which of the following devices can be powered using PoE? Electric heater VoIP handset Desktop computer Microwave oven What is the maximum power output of the 802.3at (PoE+) standard? 15.4 W 30 W 60 W 90 W What happens if a non-PoE device is connected to a PoE switch port? The switch supplies power and damages the device. The switch does not supply power to the port. The device starts working at reduced power. The switch automatically converts the device to PoE. What is the usable power provided by 802.3bt (Type 4) standard? 25 W 51 W 71 W 90 W Which term refers to the process of a switch determining if a device is PoE-enabled? Transmission Detection Conversion Distribution Explain how PoE can make network management more efficient. Describe the difference between the 802.3af and 802.3bt standards. Why is it important for a PoE switch to detect whether a device is PoE-enabled before supplying power?