Power over Ethernet (PoE) technology has become a critical part of modern network infrastructure, simplifying device installation by supplying power and network connectivity over a single Ethernet cable. Cisco offers several PoE standards: PoE+, UPoE, and UPoE+. But what’s the real difference, and how do you know which standard your organization truly needs?

This practical guide explains the technical differences clearly, shows typical use cases, and helps you choose the right PoE technology for your Cisco infrastructure.

An Ethernet switch providing power to end clients

What are PoE+, UPoE, and UPoE+?

PoE+

Cisco PoE+ (802.3at)
The industry-standard IEEE 802.3at, delivering up to 30 W per port. Ideal for powering IP phones, basic wireless APs, surveillance cameras, and other standard office equipment.

UPoE

Cisco UPoE (Universal PoE)
Cisco’s proprietary standard, providing up to 60 W per port—twice the power of PoE+. UPoE supports higher-powered devices, including advanced Wi-Fi 6 APs, video conferencing endpoints, large-screen digital signage, and compact desktop switches.

UPoE+

Cisco UPoE+ (802.3bt Type 4)
The latest IEEE standard (802.3bt), supporting up to 90 W per port. UPoE+ can power advanced devices like LED lighting systems, smart-building IoT devices, security systems, pan-tilt-zoom cameras, and large-screen collaboration displays.

Comparison: PoE+ vs UPoE vs UPoE+

Feature / Standard

PoE+ (802.3at)

UPoE (Cisco Proprietary)

UPoE+ (802.3bt Type 4)

Maximum Power per Port

30W

60W

90W

Standard Compliance

IEEE 802.3at

Cisco Proprietary

IEEE 802.3bt

Device Compatibility

Phones, basic APs, IP cameras

Video conferencing endpoints, advanced APs, digital signage

LED lighting, advanced IoT endpoints, high-power security cameras

Supported Cisco Switches

Most Cisco Catalyst and Industrial Ethernet (IE) switches

Catalyst 9300, 9400, 9500, 9600, selected IE series

Catalyst 9000 series latest models, selected advanced IE switches

Common Applications

General office equipment, SMB deployments

Enterprise collaboration, large-scale Wi-Fi deployments

Smart buildings, IoT infrastructures, advanced security

How Does Cisco PoE Power Negotiation Work?

When connecting a PoE-enabled device (Powered Device, PD), Cisco switches follow a clear three-stage negotiation process to safely and efficiently supply power:

1. Detection Phase

  • The Cisco switch sends a low-voltage detection signal to verify if the connected device supports PoE.
  • The PD responds, confirming it’s ready to receive power.

2. Classification Phase

  • After detection, the PD communicates its power class to the switch.
  • Common PoE classes:

PoE Class

Standard

Maximum Power per Port

Typical Usage

Class 1

PoE (802.3af)

4W

Basic IP Phones, Sensors

Class 2

PoE (802.3af)

7W

Standard IP Phones, Simple Cameras

Class 3

PoE (802.3af)

15.4W

Advanced IP Phones, Wireless APs

Class 4

PoE+ (802.3at)

30W

Multi-radio Wireless APs, PTZ Cameras

Class 5

UPoE (802.3bt)

45W

Video Conferencing Units, Small Displays

Class 6

UPoE (802.3bt)

60W

Digital Signage, Advanced APs

Class 7

UPoE+ (802.3bt)

75W

Smart Building Sensors, IoT Endpoints

Class 8

UPoE+ (802.3bt)

90W

LED Lighting, High-power IoT, Large Displays

3. Power Delivery & Monitoring Phase

  • The Cisco switch delivers the requested power to the PD.
  • Continuously monitors and dynamically adjusts power usage.
  • Automatically reclaims unused power to optimize power distribution.

Real-world Usage Scenarios & Applications

  • PoE+ (802.3at):
    Suitable for standard enterprise scenarios. If your business primarily uses IP telephones, simple IP cameras, or standard Wi-Fi access points, PoE+ is usually sufficient.
  • UPoE (Cisco proprietary):
    Necessary for enterprises needing advanced collaboration solutions—video conferencing terminals, Cisco Webex Room Kits, large-screen displays, and modern multi-radio access points.
  • UPoE+ (802.3bt):
    Best for future-proofing your infrastructure, powering next-gen IoT devices, building automation systems, LED smart lighting, high-power security cameras, and pan-tilt video cameras requiring higher wattage.

How to Choose the Right Cisco PoE Standard

Consider these factors when selecting between PoE+, UPoE, and UPoE+:

  • Your Current and Future Power Requirements:
    Estimate power usage of devices you plan to install. If uncertain, lean towards UPoE or UPoE+ to avoid future upgrades.
  • Device Compatibility:
    Check device specs. Some newer IoT endpoints or advanced APs explicitly require UPoE or UPoE+.
  • Budget & Cost Efficiency:
    PoE+ switches generally cost less than UPoE/UPoE+ switches. However, investing upfront in higher wattage capability may reduce long-term upgrade costs.
  • Future Expansion Plans:
    If planning significant growth or deploying emerging IoT devices, selecting UPoE or UPoE+ is often smarter for long-term scalability.

Cisco Switch Models Compatible with PoE+, UPoE, and UPoE+

The key part relevant to PoE capability is the indicator at the end of the model number:

Cisco PoE Indicator

PoE Standard Supported

Max Power per Port

P

PoE+ (802.3at)

30W

U

UPoE

60W

H

UPoE+ (802.3bt)

90W

For example:

  • Cisco Catalyst C9300-48P:
    48-port Catalyst 9300 switch supporting standard PoE (30W per port).
  • Cisco Catalyst C9300-48U:
    48-port Catalyst 9300 switch supporting UPoE (60W per port).
  • Cisco Catalyst C9300-24H:
    24-port Catalyst 9300 switch supporting UPoE+ (90W per port).

Learn More: How to Decode Cisco Catalyst Switch SKU and Identify Device Types

How to Enable and Verify PoE on Cisco Switches

After selecting the right PoE standard, you’ll need to enable and verify PoE settings on your Cisco Catalyst switches. Follow these straightforward steps:

Step 1: Enable PoE on a Cisco Switch Interface

Cisco switches typically have PoE enabled by default, but you might occasionally need manual intervention. To ensure PoE is active on a specific interface, enter configuration mode and use these commands:

Switch# configure terminal
Switch(config)# interface GigabitEthernet1/0/1
Switch(config-if)# power inline auto
Switch(config-if)# exit
Switch(config)# exit
Switch# write memory
  • power inline auto: enables automatic PoE detection and power provisioning on this port.

Step 2: Verify PoE Status and Power Consumption

To quickly confirm your Cisco switch’s current PoE usage and capability, run these common commands:

Switch# show power inline

This command displays real-time power consumption and available power on all ports.

Example Output:

Interface Admin  Oper       Power(Watts)     Device
--------- ------ ---------- ----------------- -------
Gi1/0/1   auto   on         15.4              IP Phone
Gi1/0/2   auto   off        0.0               n/a
...

To check detailed power capabilities of your switch:

Switch# show power inline capability
  • Provides detailed PoE information per interface, showing if ports support PoE, PoE+, UPoE, or UPoE+.

Example Output:

Interface  PoE Capability
---------- --------------
Gi1/0/1    PoE/PoE+
Gi1/0/24   PoE/PoE+/UPoE
...

These straightforward commands help you quickly verify your Cisco PoE setup, ensuring all connected endpoints receive appropriate power and function smoothly.

FAQ

Can I mix PoE+ and UPoE devices on one switch?

Absolutely. Cisco’s UPoE and UPoE+ ports automatically deliver the right power for each device—no manual tuning needed.

How do I check if my current Cisco switches support UPoE or UPoE+?

Use the Cisco Feature Navigator tool or check the official product datasheet. You can also run the CLI command show power inline capability.

Is special licensing required for UPoE or UPoE+?

Typically no special licensing for basic PoE features, but certain advanced power management features might require specific Cisco software licenses (e.g., Cisco DNA Advantage).

Is UPoE+ compatible with older PoE or PoE+ devices?

Absolutely. UPoE+ ports can supply power to older PoE and PoE+ endpoints without issue.

Conclusion & Next Steps

Choosing between Cisco PoE+, UPoE, and UPoE+ ultimately depends on your specific device power requirements, deployment scenario, and future growth strategy.

  • For most basic office networks: PoE+ (802.3at) is adequate.
  • For high-powered collaboration devices: Choose UPoE (60W).
  • For future-proofing or smart-building initiatives: UPoE+ (802.3bt, 90W) is the safest choice.

Still not sure which PoE standard is best for your deployment? Send us your device list or network diagram—our Cisco-certified team will recommend the right models and even help you optimize for future expansion.

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