Troubleshooting Slow Speed on Your Main Deco: Ethernet and Wi-Fi Fixes

This guide covers Deco slow speed issues specific to the main Deco node. Common causes include ISP connection problems, Ethernet cable quality, QoS settings, UPnP and SIP ALG configuration, and Wi-Fi channel interference. First, you’ll learn the two diagnostic steps — verifying the speed of your ISP (Internet Service Provider), and your Deco device. Then, you can address slow Ethernet and slow wireless speed separately.

Key Takeaways

• The first step in troubleshooting slow Deco mesh Wi-Fi speeds is confirming whether the issue is with the ISP connection or the Deco itself — bypass the Deco by connecting a device directly to the modem or gateway and run a speed test.
• If Ethernet speeds are slow, replacing cables with CAT5E-rated cables or above is recommended as a first fix.
• Try swapping the main Deco node with a satellite node, using the Deco app. This can help identify a hardware issue causing slow Ethernet.
• Disabling QoS in the Deco app (More, then QoS) is a common fix for slow wireless speeds.
• Turning off UPnP and SIP ALG features (More, then Advanced, then NAT Forwarding) can improve wireless speed performance.
• Wi-Fi channel interference is a common cause of slow wireless speeds — a Wi-Fi analyzer app can identify crowded channels.

Diagnosing Slow Speed on Your Main Deco

1. Check the Internet Speed Through Your Deco

First, test your internet speed and review the results using this guide: How Do I Test the Speed of my Deco Network?

2. Check the Speed From Your ISP

Temporarily unplug the main Deco from your modem or gateway. Connect a laptop or PC directly to the ISP gateway or modem and run a speed test. The speed test should report speeds similar to what you expect from your ISP, based on your internet plan.

How to Fix Slow Deco Speed

Slow Ethernet Speed

1. Replace the Ethernet cables between the ISP modem, main Deco, and laptop with new cables rated as CAT5E or above, then test the speed on the laptop again.

2. Try setting a satellite Deco as the main Deco. The Deco app includes an option to swap nodes.

Follow this FAQ to Set Up a Satellite or New Deco As the Main Deco

Slow Wireless Speed

1. Disable QoS: Deco app > More > QoS > Turn off QoS completely. Alternatively, change to Standard mode, remove all priorities, and set bandwidth to 1000Mbps.

2. Turn off the UPnP and SIP ALG features in the Deco app: More > Advanced > NAT Forwarding.

3. Try other speed test servers or platforms since some specific servers cannot reach the full speed for wireless tests. The test here has shown that if the server supports TCP BBR, the download/upload speed would be better.

4. Download a Wi-Fi analyzer app on your phone to check for wireless channel interference. Crowded channels can significantly reduce performance.