In a PoE system, which device provides power to the PDs over Ethernet?

In a PoE system, which device provides power to the PDs over Ethernet?

• A. Power Sourcing Equipment (PSE)
• B. Powered Device (PD)
• C. Uninterruptible Power Supply (UPS)
• D. Smart Switch

Answer: (A)

In PoE, the device that provides power over the Ethernet cable is the Power Sourcing Equipment. The PSE can be a PoE-enabled switch (endspan) or a separate injector (midspan). It negotiates with the Powered Device to determine how much power to supply, using the PoE standards (detect, classify, then power delivery). The Powered Device is the one that receives power (for example, an IP camera or VoIP phone). A UPS is simply backup power for devices, not the source of PoE power over the cable. A smart switch may be PoE-capable and act as a PSE, but the generic term for the power-supplying device is Power Sourcing Equipment.

In PoE, the device that provides power over the Ethernet cable is the Power Sourcing Equipment. The PSE can be a PoE-enabled switch (endspan) or a separate injector (midspan). It negotiates with the Powered Device to determine how much power to supply, using the PoE standards (detect, classify, then power delivery). The Powered Device is the one that receives power (for example, an IP camera or VoIP phone). A UPS is simply backup power for devices, not the source of PoE power over the cable. A smart switch may be PoE-capable and act as a PSE, but the generic term for the power-supplying device is Power Sourcing Equipment.