optimising-unifi-performance

optimising-unifi-performance.md

optimising-unifi-performance

NOTE: Content below is written by Adrian Mace. Click here for an updated version.

Below are the key settings that I apply on any unifi installation for optimal performance.

Settings

Settings > Site

• Ensure Enable Advanced Features is enabled
  This allows you to follow along with the guide in it's entirety.

• Ensure Automatically Optimise Network and WiFi performance is disabled
  These settings will do a better job.

Settings > Wireless Networks > YOUR-NETWORK-HERE > Edit

• Ensure Fast Roaming is disabled
  It creates a lot more 'noise' on the dashboard in the form of anomalies when you have more than one access point within a home environment, and is useless if you only have a single one.
  At the time of writing it's also a BETA feature.

• Ensure Combine 2 GHz and 5 GHz WiFi Network Names into one is enabled
  With these optimised settings you'll see devices only using 2.4GHz if they either a) don't support 5GHz (thanks Google!) or b) are too far away to maintain a reliable connection.

• Ensure Connects high performance clients to 5 GHz only is disabled
  With these optimised settings you'll see devices always prefer 5GHz, and at the time of writing, the current method to detect 'high performance clients' is not reliable.

• Ensure DTIM Mode default values is disabled
  This is the interval in which the access point polls the devices to check if they're alive. For many Apple / iOS devices, this causes them to not sleep correctly which both causes anomalies on the dashboard and kills the device battery life.

  • Set DTIM 2G Period to 3
  • Set DTIM 5G Period to 3

Settings > Try New Settings > WiFi AI

• Ensure Enable WiFi AI is disabled
  This is a great feature, but I found it to be choosing channels that were DFS (radar in the area causes intermittent dropouts of your network) or just not selecting channels 1 / 6 / 11.

Devices

Devices > YOUR-ACCESS-POINT-HERE > Config > Radios

• Ensure Channel Width is set to the following

  • Radio 2G should be set to HT20
  • Radio 5G should be set to VHT80 or VHT160 (HD series)

• Ensure Transmit Power is set to the following

  • Radio 2G should be set to Medium
  • Radio 5G should be set to High

• Ensure Channel is set appropriately
  Run a WiFi scanning utility and pick the least congested channel. This is outside the scope of this doc.

Devices > YOUR-ACCESS-POINT-HERE > Config > Band Steering

• Ensure Band Steering is set to Prefer 5G
  This ensures that clients will connect on the 5GHz channel when available.

Devices > YOUR-ACCESS-POINT-HERE > Config > Airtime Fairness

• Ensure Airtime Fairness is set to On
  This ensures that the access point shares data between connected clients on a time division multiplexing basis, rather than the default which allows a certain amount of bandwidth to be transferred before moving on.
  In practice if this is not enabled, a small Raspberry Pi connected to a far-away AP at 54Mbps will drag every other connected device's effective bandwidth down to 54Mbps until the Pi is powered off or moved to a different AP.

Forcing your transmit power to HIGH generally is not a good idea for performance.

To quote Evan McCann:

5 GHz and 6 GHz attenuate more rapidly and are more affected by obstructions, resulting in around half the range of 2.4 GHz. If you have a very dense area or a smaller home or business with multiple APs, setting a unique channel and keeping 5 GHz TX power on low or medium may be best. For those trying to achieve the most range and coverage from the APs they have, high 5 GHz and 6 GHz TX power can be set.

And Ubiquiti:

The high transmit power (TX power) of UniFi APs is great for single-AP installations, but can be problematic in enterprise/multi-AP deployments. The high TX power will extend the range for slower TX rates only, as faster rates are transmitted at a lower TX power, which is normal for ALL APs and devices. This eats up air-time for faster rates in multi-AP deployments, slowing down the entire network and potentially causing packet loss.