Understanding the Differences Between POE, POE+, POE++ and POE+++ Standards

Power over Ethernet (PoE) technology has transformed how devices receive power and data through a single cable. This innovation simplifies installations, reduces clutter, and improves flexibility for network devices like IP cameras, wireless access points, and VoIP phones. However, not all PoE standards are the same. The terms POE, POE+, POE++, and POE+++ refer to different power delivery capabilities and technical specifications.

This post breaks down these standards, explaining their differences, power limits, and typical use cases. Whether you are setting up a small office network or managing a large enterprise infrastructure, understanding these standards helps you choose the right equipment for your needs.

What is Power over Ethernet (PoE)?

PoE allows network cables to carry electrical power alongside data. This eliminates the need for separate power supplies or outlets near devices, making installations cleaner and more cost-effective. The technology uses standard Ethernet cables (Cat5e, Cat6, etc.) to deliver both power and data.

The original PoE standard was developed to support devices requiring low to moderate power levels. Over time, as devices demanded more power, new standards emerged to meet these needs.

POE (IEEE 802.3af) – The Original Standard

The first PoE standard, IEEE 802.3af, was ratified in 2003. It provides up to 15.4 watts of DC power per device over Cat5 cables. Due to power loss in cables, the maximum power available at the device end is about 12.95 watts.

Typical devices powered by POE include:

• VoIP phones

• Basic wireless access points

• Simple IP cameras

  
  

POE works well for devices with low power requirements but cannot support more demanding equipment.

POE+ (IEEE 802.3at) – Higher Power for More Devices

Introduced in 2009, POE+ (802.3at) increased the power delivery to up to 30 watts per port, with about 25.5 watts available at the device. This standard supports devices that need more power than the original PoE can provide.

Common POE+ devices:

• Pan-tilt-zoom (PTZ) IP cameras

• More advanced wireless access points

• Video phones and other multimedia devices

  
  

POE+ is backward compatible with POE, meaning it can power devices designed for the original standard without issues.

Ethernet cable connected to a network switch port, showing power delivery capabilities

POE++ (IEEE 802.3bt Type 3) – Power for Demanding Devices

The POE++ standard, also known as IEEE 802.3bt Type 3, was ratified in 2018. It significantly increased power delivery, providing up to 60 watts per port, with about 51 watts available at the device.

This standard supports devices that require higher power, such as:

• High-performance wireless access points

• Video conferencing systems

• Thin clients and small computers

• LED lighting systems

  
  

POE++ uses all four pairs of wires in Ethernet cables to deliver this higher power, compared to the two pairs used in earlier standards.

POE+++ (IEEE 802.3bt Type 4) – The Highest Power Standard

The latest PoE standard, IEEE 802.3bt Type 4, sometimes called POE+++, pushes power delivery even further. It can provide up to 100 watts per port, with about 71 watts available at the device after cable losses.

This standard supports the most power-hungry devices, including:

• Large video displays

• High-end pan-tilt-zoom cameras with heaters

• Network switches powered by PoE

• Industrial automation equipment

  
  

POE+++ also uses all four wire pairs and requires compatible switches and injectors designed to handle this power level.

Key Differences Between POE Standards

| Standard | Max Power at Source | Max Power at Device | Wire Pairs Used | Typical Devices |

|----------------|---------------------|---------------------|-----------------|-----------------------------------------|

| POE (802.3af) | 15.4 W | 12.95 W | 2 pairs | VoIP phones, basic cameras, APs |

| POE+ (802.3at) | 30 W | 25.5 W | 2 pairs | PTZ cameras, advanced APs, video phones |

| POE++ (Type 3) | 60 W | 51 W | 4 pairs | High-performance APs, video systems |

| POE+++ (Type 4)| 100 W | 71 W | 4 pairs | Large displays, industrial devices |

Choosing the Right PoE Standard for Your Setup

Selecting the correct PoE standard depends on the power requirements of your devices and the infrastructure you have.

• For low-power devices, such as basic IP phones or simple cameras, the original POE standard is sufficient.

• For devices needing more power, like PTZ cameras or advanced wireless access points, POE+ is a better fit.

• For high-power devices, including video conferencing systems or LED lighting, POE++ offers the necessary power.

• For the most demanding equipment, such as large displays or industrial machinery, POE+++ is the only option.

  
  

Make sure your network switches or PoE injectors support the required standard. Using a lower standard than needed can cause devices to malfunction or not power on.

Network switch with Ethernet cables connected, demonstrating various PoE power levels

Practical Tips for Using PoE Standards

• Check device specifications for power requirements before purchasing PoE equipment.

• Use quality Ethernet cables (Cat5e or higher) to ensure efficient power delivery.

• Consider cable length: longer cables can reduce power available at the device due to voltage drop.

• Ensure compatibility between PoE switches/injectors and powered devices.

• Plan for future upgrades by choosing switches that support higher PoE standards if you expect to add more power-hungry devices.