Understanding PoE (Power over Ethernet) stack and its benefits

PoE, or Power over Ethernet, might sound a bit nerdy at first, but it's one of the most practical tools in the networking world. It lets you power devices like access points, IP cameras, and VoIP phones, all through the same Ethernet cable that carries data. That means fewer cables, fewer outlets, and a cleaner, more efficient setup.

Let’s dig into what PoE is, what stacking means, and why it’s worth considering in any serious UniFi setup.

what is PoE? PoE allows network cables to carry both electrical power and data. Instead of installing power outlets near each access point or camera, you just run a network cable from a PoE switch to the device. Simple as that.

UniFi access points, cameras, phones, most of them support PoE. You power them and get network connectivity through the same cable. That means no power bricks or splitters to deal with, and no need to hire an electrician to run new power lines.

The concept isn’t new, it’s been around for years, but it's become standard in enterprise-grade networking.

PoE standards and power limits There are a few official standards you should know:

802.3af (PoE): Delivers up to 15.4W per port. Good for basic access points and VoIP phones.

802.3at (PoE+): Delivers up to 30W per port. Ideal for high-power APs and HD cameras.

802.3bt (PoE++): Comes in two flavors:

Type 3: Up to 60W

Type 4: Up to 100W

High-end UniFi devices like the G4 Pro camera or UniFi LED panels may require PoE++. Always check the device’s power requirements before plugging it into a switch.

passive vs active PoE UniFi also has some older gear that uses "passive PoE" which is not standardized. It usually means 24V, and you have to match the power source exactly. Newer UniFi switches don’t support passive PoE by default, so check your device before connecting it to a PoE switch.

how PoE switch stacking works When we talk about a “PoE stack,” we’re referring to a group of PoE switches that are physically connected and logically managed as a single unit. It’s kind of like daisy-chaining switches, but done in a way that keeps everything centralized and efficient.

There are two types of stacking:

Physical stacking: Uses special cables or ports to link switches.

Virtual stacking: Links switches over Ethernet and manages them together using the controller.

UniFi uses the virtual stacking approach. You don’t need a proprietary cable or config — you just add UniFi switches to your controller, and you can manage them all from one dashboard.

With a PoE switch stack, you can:

Monitor all ports and power usage in one place

Apply updates and settings across the board

Scale by just adding another switch

Distribute PoE loads more efficiently

It’s great for networks with dozens of endpoints. And it’s cleaner than dealing with separate switches spread around without centralized control.

benefits of using a PoE stack in UniFi Let’s look at why this actually matters:

1. centralized power management With a stack of PoE switches, you can see exactly how much power each port is using, and how much is available. If you're nearing the PoE budget, you’ll know before anything cuts out. This is especially handy in setups with cameras and APs that have varying power needs.
2. easy provisioning and automation When switches are stacked in UniFi, provisioning becomes a breeze. You can configure VLANs, firewall rules, and port profiles in one place. New devices plug in, and the controller takes care of the rest.
3. efficient troubleshooting Say one camera goes offline. Instead of checking every cable or running from room to room, you open the controller, check the switch port, and see the power status. Maybe the port is disabled. Maybe the device is drawing too much current. You’ll know in seconds.
4. simplified cabling With PoE, you don’t need two cables (power + data). One Cat6 cable handles both. In places with limited space or messy ceiling installations, this is huge.
5. scalability Need to add more devices? Add another switch to the stack. UniFi makes it easy — and the switches will auto-adopt into your existing controller setup. You don’t need to rewire the network or reconfigure VLANs.

how to plan your PoE stack Here’s what to consider when designing a PoE setup:

calculate your PoE budget Each switch has a total PoE power budget, usually listed in watts. A UniFi Switch 24 PoE might offer 200W total, while a 48-port version might go up to 600W.

Example:

6 x UniFi U6-LR APs @ 18.5W each = 111W

4 x G4 Bullet cameras @ 9W each = 36W

Total = 147W

In that case, a 200W switch is fine. But if you add LED panels, VoIP phones, or a UniFi ViewPort, you’ll need more headroom.

know your deployment zones Don’t dump all switches in one rack if your site is spread out. Use a central PoE stack and then run cabling out to remote devices. Or, install smaller PoE switches at remote locations and link them back to the main controller.

use UPS (uninterruptible power supply) If your switches are powering everything, a power outage takes down the whole network. Add a UPS to your PoE stack to keep your APs and cameras running through short outages.

go for managed switches UniFi switches are fully managed, which means:

Remote reboot of individual ports

VLAN tagging

Port isolation

Link speed control

Real-time traffic analysis

Don’t skimp on this. Managed switches give you visibility and control that unmanaged switches can’t.

real-world example: multi-floor office Imagine you’ve got a 3-story office. Each floor has:

6 UniFi APs

4 cameras

A few IP phones

A wired printer

You place one UniFi 24 PoE switch per floor, linked with fiber back to the core switch in the server room. That’s your PoE stack. Now you can:

Power everything with one switch per floor

View all three switches in one UniFi dashboard

Apply updates across all switches

Add more devices without extra configuration

No external power adapters, no mess.

advanced tip: using PoE for redundancy Some high-end setups use PoE for device redundancy. For example, a UniFi Protect camera can be powered by two switches, one main and one backup, through a PoE failover mechanism. Not standard, but doable with injectors or custom wiring.

It’s also common to have critical APs on separate PoE switches powered by independent UPS units. That way, if one switch or power source fails, the rest of the network stays up.

PoE injectors vs switches In small setups, you might consider PoE injectors instead of a switch. They’re cheaper and plug inline between your router and device.

But once you hit more than 2–3 PoE devices, switches are the better choice:

Easier cable management

Cleaner control

Better monitoring

Safer and more efficient

conclusion PoE is one of those things that sounds niche until you use it. Then you wonder how you ever lived without it. It makes installations faster, cleaner, and cheaper, especially when you’re rolling out dozens of devices.

And when you pair PoE with UniFi switch stacking, the benefits really start to stack up (pun intended). You get centralized control, easy scaling, better monitoring, and way less troubleshooting.

And if setting all of this up sounds like a headache, we’ve got you. At Unihosted, we host your UniFi controller in the cloud so you don’t have to. You get full control over your PoE stack and every device, from anywhere, with automatic updates and backups. Plus, we’ve got a free plan if you want to try things out first