PoE+ vs PoE++: Differences for Enterprise Networks

Power over Ethernet, or PoE, is a networking feature that lets Ethernet cables carry electrical power alongside data. This technology simplifies installations for devices like IP cameras, wireless access points, and VoIP phones by eliminating the need for a separate power source.

As network devices have become more powerful, PoE technology has evolved into different standards to meet higher power demands. Two of the most common standards you'll encounter are PoE+ (802.3at) and PoE++ (802.3bt). Understanding their differences is key to building a reliable and future-proof network.

What is PoE+?

PoE+, also known by its technical name, the IEEE 802.3at standard, is an enhancement of the original PoE technology. It was introduced to power devices with higher energy needs, such as pan-tilt-zoom (PTZ) cameras, multi-radio wireless access points, and video IP phones. It provides a significant power boost over the initial standard while using the same familiar Ethernet cabling.

Here are the core technical details of PoE+:

• Power Delivery: It supplies up to 25.5 watts of power to the end device.
• Power Sourcing: The power sourcing equipment (PSE), such as a network switch, provides a maximum of 30 watts of power per port.
• Voltage Range: It operates at a voltage between 50 and 57 volts DC from the PSE.
• Cabling Requirement: It functions reliably over Cat5 cabling or better.

What is PoE++?

As device power requirements grew, another standard was needed. Enter PoE++, officially known as the IEEE 802.3bt standard. It significantly increases the power budget to support demanding hardware like digital signage, high-performance access points, and even small network switches. PoE++ is divided into two categories, Type 3 and Type 4, which offer different power levels.

Here’s a breakdown of its technical specifications:

• Power Delivery: Type 3 provides up to 51 watts, while Type 4 delivers up to 71 watts to the end device.
• Power Sourcing: The PSE provides up to 60 watts per port for Type 3 and up to 100 watts for Type 4.
• Cabling Requirement: It requires Cat5e cabling at a minimum, though Cat6a is often recommended for higher power applications to better manage heat.

Key Differences Between PoE+ and PoE++

While both standards send power over Ethernet cables, they differ in a few critical areas that impact network design and device support. The primary distinctions come down to power output, how they use the cable wiring, and their compatibility with other devices.

Power Delivery

The most fundamental difference is the amount of power each standard can supply. PoE+ provides up to 25.5W to a connected device, which is suitable for hardware like PTZ cameras and multi-radio access points.

PoE++ significantly increases this capacity, delivering up to 51W with Type 3 and up to 71W with Type 4. This makes it capable of supporting more demanding equipment like digital signage or small network switches.

Ethernet Pairs Utilized

Another key technical distinction is how the standards use the wires within an Ethernet cable. PoE+ technology sends power over two of the four available twisted pairs.

To achieve its higher power output, PoE++ uses all four twisted pairs. This allows it to deliver more electricity more efficiently to the end device.

Backward Compatibility

PoE++ equipment is designed to be backward compatible. This means a PoE++ switch port can safely power a PoE+ or a standard PoE device, as it will only supply the amount of power the device requests.

However, the reverse is not true. A PoE+ switch cannot power a device that requires a PoE++ connection because it cannot meet the higher power demand.

Benefits of Using PoE+

PoE+ hits a sweet spot between power delivery and cost, making it a go-to choice for many business networks. Since the technology is more mature than PoE++, compatible switches and powered devices are generally more affordable and widely available from a larger pool of vendors. This gives IT teams greater flexibility when sourcing equipment.

The standard provides sufficient power for a huge range of common enterprise hardware, from advanced VoIP phones to pan-tilt-zoom security cameras. For deployments where the higher output of PoE++ is overkill, PoE+ delivers a reliable and cost-effective solution.

It also simplifies network rollouts and lowers installation costs. By using a single cable for both data and power, you can avoid the expense of hiring an electrician to install new outlets, which is a major advantage in older buildings or areas that are difficult to access.

Advantages of PoE++

The primary advantage of PoE++ lies in its sheer power capacity. By delivering up to 71W, it opens the door for a new class of high-performance devices that PoE+ simply can't support. This makes it an excellent choice for future-proofing your network infrastructure, ensuring you can accommodate more demanding hardware down the line without needing to upgrade your switches.

Beyond raw power, PoE++ is also more efficient. Because it uses all four twisted pairs in an Ethernet cable, it minimizes power loss over long cable runs. This higher power budget also allows for greater device consolidation, enabling you to power multiple devices from a single port using a PoE splitter, which simplifies your network topology.

Use Cases for PoE+ and PoE++

Choosing the right standard depends on the specific devices you need to power. Here’s a practical look at where each technology shines in a typical business environment.

PoE+ Use Cases

• VoIP and Video Phones: It reliably powers advanced office phones that feature color displays and video conferencing capabilities.
• Wireless Access Points: PoE+ is sufficient for most standard business-grade wireless access points that manage moderate network traffic.
• Security Cameras: It supports common surveillance equipment, including pan-tilt-zoom (PTZ) cameras that require more power to operate their motors.

PoE++ Use Cases

• High-Performance Networking: It is essential for power-hungry Wi-Fi 6/6E access points and small network switches that extend connectivity.
• Digital Signage: PoE++ can run large, bright displays, information kiosks, and video walls without separate power wiring.
• Smart Building Devices: It supports modern building automation hardware, including LED lighting systems and access control panels.

Making the Right Choice for Your Network

Deciding between PoE+ and PoE++ comes down to your specific device requirements and future network plans. The best approach is to audit the power consumption of your current and planned hardware. This inventory will make it clear whether the 25.5W from PoE+ is sufficient or if you need the higher capacity of PoE++.

For most common business devices, PoE+ provides a perfectly reliable and cost-effective solution. It handles the power needs of VoIP phones and standard access points without issue.

However, if your technology roadmap includes high-performance Wi-Fi 6/6E access points, digital signage, or other power-hungry equipment, investing in PoE++ is a wise decision. Choosing PoE++ from the start helps you build a network that can support future growth without requiring expensive hardware replacements down the line.

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Frequently Asked Questions about PoE+ vs PoE++

Do I need special cabling for PoE++?

While PoE+ works fine over Cat5, PoE++ requires at least Cat5e cabling. For higher-power Type 4 applications, Cat6a is strongly recommended to better manage heat and minimize power loss, ensuring your devices receive stable power.

Can I use a PoE+ device with a PoE++ switch?

Yes, absolutely. PoE++ switches are fully backward compatible. The switch port will automatically detect the device's power requirement and supply only the lower wattage needed for the PoE+ device, so it's completely safe to mix them.

What happens if I plug a PoE++ device into a PoE+ port?

The device simply won't power on. A PoE+ port cannot provide the higher wattage that a PoE++ device demands. No damage will occur to either the switch or the device, but the device will not function.

Is there a big price difference between PoE+ and PoE++ switches?

Generally, PoE++ switches are more expensive due to their advanced power components and higher total power budget. While the price gap is narrowing, PoE+ remains the more cost-effective choice if your devices don't require the extra wattage.