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Overview of PoE


Power over Ethernet (PoE) is a method of providing electrical power through Ethernet cables. It is also called Power over LAN (PoL) or active Ethernet.


As IP phones, network video surveillance, and wireless Ethernet networks are widely applied, power supply requirements on the Ethernet become urgent. Terminals often require DC power supply, but they are often installed on the ceilings or outdoors where power sockets are unavailable. Even if power sockets are available, there is no place to install an AC/DC adapter for these terminals. On large-scale LANs, administrators need to manage multiple terminals that require uniform power supply and management. In this case, power supply management is difficult. PoE addresses this problem.

The PoE technology is used on the wired Ethernet and is most widely used on LANs. PoE allows power to be transmitted to terminals through data transmission lines or idle lines. This technology provides power over a 2.5GE Base-T, 1000Base-T, 100Base-TX, or 10Base-T Ethernet network, spanning a distance of up to 200 m. PoE complies with IEEE 802.3af and can be used to effectively provide centralized power for terminals such as IP phones, access points (APs), chargers of portable devices, POS machines, cameras, and data collection devices. PoE+ is an enhancement to PoE, complies with IEEE 802.3at, and provides high PoE power to devices with high-power applications, including dual-frequency access devices, video phones, and Pan Tilt Zoom (PTZ) video surveillance systems. Currently, PoE++ technology is also supported by Ethernet switches. It provides high PoE power to devices requiring high power.

PoE has the following advantages:

  • Reliable: Multiple powered devices (PDs) are powered by a single power-sourcing equipment (PSE) device, facilitating power backup.
  • Easy to deploy: Network terminals can be powered over network cables, without needing external power sources.
  • Standard: PoE complies with IEEE 802.3af and IEEE 802.3at, and all PoE devices use uniform power sources and can be connected to PDs of different vendors.


  • Reduces costs for power supply cabling and facilitates power module installation.
  • Works with Uninterruptible Power Supply (UPS) to provide backup power supply for IP cameras, video servers, and IP phones.
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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