Requesting assistance troubleshooting a Ubiquiti Wi-Fi that uses only 29% network capacity

[qwertyit]

Our IT team is requesting assistant troubleshooting a long term, persistent slow Wi-Fi performance with our Ubiquiti setup, despite having a gigabit internet connection and modern hardware.

 

Current Setup:

• Internet: Gigabit fiber connection

• Wi-Fi Equipment: Ubiquiti Wi-Fi 6 (purchased ~2 years ago)

• Endpoints: This is a new company and all laptops are within 4 years old, with most being about 1 year old. All are capable of Wi-Fi 5, and most are capable of Wi-Fi 6.

• Access Points:

  • 15 total

  • 14 in the main office building

  • 1 in in another office building on the edge of the campus location (not in range of the other 14). This access point is connected to a Ubiquiti switch that has a fiber uplink the core of the network in the main building.

• Users & Devices:

  • ~80 employees in the office

  • ~150 devices connected on average

  • Peaks at ~300 devices

• Performance Cap:

  • Wi-Fi connection maxes out at 291 Mbps combined network traffic aggregated from all access points(far below expected Wi-Fi 6 performance)

  • At times, speeds drop below 4 Mbps

Symptoms:

• Devices (Windows & macOS laptops) do not roam properly between APs

  • Users remain connected to distant APs even after moving through the building

• Slow speeds are consistent across both the remote AP and the main building APs

• Remote AP slowness correlates with main office network degradation

 

Troubleshooting Done So Far:

• Access Point Tuning:

  • Power set to medium

  • Minimum RSSI enabled

  • Conservative Mode disabled

  • Interference compensation turned off

  • Overlapping channels and APs disabled

• Network & Hardware:

  • All APs use Ethernet uplink (mesh disabled)

  • Switch and AP speeds set to maximum

  • Ethernet uplink cables replaced

  • APs moved to different switches/ports

  • Data continuity on Ethernet verified

• Device & Traffic Management:

  • BYOD devices segmented on VLANs

  • Network set to prefer 5 GHz and 6 GHz bands (to steer away from 2.4 GHz)

  • Unneeded devices disconnected

  • All equipment power-cycled

 

What We’re Asking:

• Despite multiple consultants confirming our network should be fast, we’re still getting extremely poor performance.

• What else can we try to resolve this persistent slowness?

• Could there be a bottleneck or throttling on the network somewhere we have not found? Could the Ubiquiti Wi-Fi aggregation device, which has not been replaced, be an issue?

• Replacing the Ubiquiti equipment is not an option due to budget constraints.

Any insights and assistance are appreciated.

 

Thank you!

[Biohazard777]

39 minutes ago, qwertyit said:

Despite multiple consultants confirming our network should be fast, we’re still getting extremely poor performance.
What else can we try to resolve this persistent slowness?

Contact Ubiquiti

[manikyath]

54 minutes ago, qwertyit said:

Access Points:

• 15 total

contact a specialist, they'll probably have it sorted out in an afternoon, and it will cost less than your 80 employees lose in productivity every day.

[johnt]

What is the minimum RSSI you are setting the APs to?

[qwertyit]

18 hours ago, manikyath said:

contact a specialist, they'll probably have it sorted out in an afternoon, and it will cost less than your 80 employees lose in productivity every day.

Good suggestion. We already had two teams of specialists from outside the company work on this, and they could not resolve the issue either.

[OddOod]

Nuke it and rebuild from scratch? Or talk to Ubiquiti

[qwertyit]

22 hours ago, johnt said:

What is the minimum RSSI you are setting the APs to?

Here is additional information about our configuration

2.4 GHz
Channel Width 20 instead of 40
Channel Auto
Transmit Power Medium; this was reduced from high to encourage endpoints to connect to the nearest access point
Minimum RSSI -67, lowest setting

 

5 GHz
Channel Width 80 instead of 160
Channel Auto
Transmit Power Medium
Minimum RSSI -67, lowest setting
Interference Blocker: Checked; previous troubleshooting steps have unchecked this without improvement
Mesh: disabled

 

Band Steering
Prefer 5 GHz

[qwertyit]

3 hours ago, OddOod said:

Nuke it and rebuild from scratch? Or talk to Ubiquiti

Unfortunately nuke and rebuild isn't an option since the company wants to try to fix what we have.

[johnt]

2 hours ago, qwertyit said:

Unfortunately nuke and rebuild isn't an option since the company wants to try to fix what we have.

he means reset the components and redo the configurations ... no new hardware 

[OddOod]

3 hours ago, qwertyit said:

Unfortunately nuke and rebuild isn't an option since the company wants to try to fix what we have.

Johnt is correct. I meant reset everything to factory settings and rebuild the network one device at a time

[johnt]

Could you also better explain what you mean by slow WiFi performance?

 

Edit: I mean, could you emphasize if you get the proper bandwidth if you have a mobile device near field to an AP that it is connected to? Do you get near 1 Gbps on that device when you run a speed test?

[Needfuldoer]

On 6/16/2025 at 3:40 PM, qwertyit said:

Devices (Windows & macOS laptops) do not roam properly between APs

• Users remain connected to distant APs even after moving through the building

I bet this is why:

 

15 hours ago, qwertyit said:

Minimum RSSI -67, lowest setting

Try raising that setting. That should encourage your devices to hop between APs properly.

 

You'll also have to look at your building's layout and how your APs are distributed. Ideally their bubbles of influence shouldn't overlap too much. Have you done an RF survey?

 

[johnt]

I've also noticed that my wifi does not "play nicely" with my client devices when I have the 5 band enabled on the same wifi as 2.4 GHz. I have to keep them separate because sometimes it will roam between APs (as it is supposed to do) and sometimes it just switches bands which is very jarring to me. It just switches from 5 to 2.4 on the same AP instead of roaming to another AP. It's strange behavior, but I'm not a wifi signal lol And unfortunately, I've had to just disable 6 GHz altogether because I have one large dead zone in my house and it just kills the entire experience for me. I've also noticed our iPhones (15 pro max ans 15 pro) do not like the 6 GHz band for extended connections. They constantly stop responding. The 5 GHz band has been a great middle ground of speed and reliability.

 

I recommend you try separating the 2.4 and 5 GHz bands into separate wifi SSIDs and just use auto for RSSI. I would also reduce the number of APs that broadcast the 2.4 signal. At this point, you have to consider if you even need 2.4 GHz anymore with so many APs. But my last recommendation is to disable band steering. It doesn't work that great. Problem is, 2.4 connects first because it is a stronger signal at a farther distance. So you approach an AP, the 2.4 band picks up. As you get closer or roam between APs, your devices have to think about switching bands and which AP, and it just adds a lot of unnecessary processing to the overall experience. You would think it's fast and should be easy, but band steering was a no go for me. It always connected to 2.4 first and held on strong lol. Separating 2.4 and 5 GHz bands is the best approach.

[qwertyit]

Understood, thanks. We tried that too.

[qwertyit]

12 hours ago, Needfuldoer said:

I bet this is why:

 

Try raising that setting. That should encourage your devices to hop between APs properly.

 

You'll also have to look at your building's layout and how your APs are distributed. Ideally their bubbles of influence shouldn't overlap too much. Have you done an RF survey?

 

the 14 access points in the main building are all in the same bubble and in range of the each other. The 1 that is remote on the campus is out of range of the other 14. The 1 that is remote runs slow when the other 14 are slow. We have also used a Hacker RF One to confirm that the access points from our corporate neighbors are out physically out of range of our access points and not in range or interfering. We have also scanned for rogue access points or other RF interference from other devices on the campus and not found any.

[qwertyit]

14 hours ago, johnt said:

Could you also better explain what you mean by slow WiFi performance?

 

Edit: I mean, could you emphasize if you get the proper bandwidth if you have a mobile device near field to an AP that it is connected to? Do you get near 1 Gbps on that device when you run a speed test?

We have never reached the maximum speeds of the access points, even when I have visited the campus late at night when no one else is on the campus except the physical security team. The Wi-Fi network never saturates the available bandwidth, even when users on site and the number of connected devices are minimal.

[qwertyit]

12 hours ago, Needfuldoer said:

I bet this is why:

 

Try raising that setting. That should encourage your devices to hop between APs properly.

 

You'll also have to look at your building's layout and how your APs are distributed. Ideally their bubbles of influence shouldn't overlap too much. Have you done an RF survey?

 

Thanks for the recommendation. We just re-tested raising the RSSI and it didn't change the behavior. Users are still roaming between access points when they are sitting at their desks, then not roaming when the users are moving around the building. Initially the access points were deployed with a higher setting, and we lowered as a part of troubleshooting.

[johnt]

1 hour ago, qwertyit said:

We have never reached the maximum speeds of the access points, even when I have visited the campus late at night when no one else is on the campus except the physical security team. The Wi-Fi network never saturates the available bandwidth, even when users on site and the number of connected devices are minimal.

This is plausible. I had issues with my Unifi gear just transferring files between wired devices. It would never saturate the full 2.5 Gbps bandwidth because they were on separate VLANs. I did it for security but it was causing me grief so I had re structure my physical devices so the devices that had to transfer a lot of files were on the same VLAN.

 

1 hour ago, qwertyit said:

Thanks for the recommendation. We just re-tested raising the RSSI and it didn't change the behavior. Users are still roaming between access points when they are sitting at their desks, then not roaming when the users are moving around the building. Initially the access points were deployed with a higher setting, and we lowered as a part of troubleshooting.

You should separate or disable 2.4 GHz band altogether to see if that makes an improvement. It was long winded but I added a post recommending:

• Separate the 2.4 and 5 GHz bands, and disable 6 GHz
• Disable band steering
• Disable RSSI (or set to auto)

I also recommended reducing the number of APs that output a 2.4 GHz signal.

[Bdavis]

You never mentioned what you're using as a router, or if you can achieve full gigabit speeds using a wired connection.

 

Start at the beginning of your network and test your speeds there. Your ISP may not be giving you your full gigabit especially during peak hours.

 

You have a pretty large network. Is it built with several daisy chained switches or is everything run to a central rack?

[NobleGamer]

On 6/16/2025 at 3:40 PM, qwertyit said:

Wi-Fi connection maxes out at 291 Mbps combined network traffic aggregated from all access points(far below expected Wi-Fi 6 performance)

First, this is all Unifi and not some other UI product or a mix with non-UI, correct? As a UCG Ultra user who used to have a UISP ER-X, there is a HUGE difference.

 

Can you confirm that there is not the same issue with wired connections?

 

Because if there is the same issue with wired connections, then you need to look at Hardware Acceleration / Offloading.

 

It will be auto disabled if you have ANY Smart Queue enabled for any Internet config or any QoS rules of any kind, even the "critical priority appplications" option you can opt into when initially setting up your Unifi solution.

In my experience, Internet connections top out at ~200 mbps on a basic gateway (you'd need to search for your model to confirm its SQM throughput range), and that can be even lower with QoS enabled. It is not an issue for me because my internet speeds only sometimes max out at 200, but I get how this can be a problem for a business at acale.

[Falcon1986]

On 6/18/2025 at 11:28 AM, qwertyit said:

Thanks for the recommendation. We just re-tested raising the RSSI and it didn't change the behavior. Users are still roaming between access points when they are sitting at their desks, then not roaming when the users are moving around the building. Initially the access points were deployed with a higher setting, and we lowered as a part of troubleshooting.

You need a different team (particularly one experienced in Ubiquiti) on the ground to diagnose and fix these problems. See if Crosstalk Solutions, Willie Howe, MacTelecom, or Lawrence Systems is accessible in your area (all reachable on YouTube) and request a consultation. If none are accessible, consider posting on Rogue Support.

 

From my point of view, you won't get much headway without someone who can physically look at your APs, their mounting locations, wired links, etc. and manipulate settings in UniFi Network. Good effort in trying to describe the scenario, but you're dealing with more than a simple setup.

 

An additional workup that you can have on hand is a Signal/Floorplan Mapper analysis using the WiFiman app with your device's built-in camera.