WEB660S - upload speed in time get slower?

Hi @Jaroslav_PRG,

I understand you're experiencing a significant drop in upload speed on your WEB660S after a few hours of operation, despite an initial normal performance of 2Gb download / 1Gb upload. This issue persists even after resetting the configuration and disabling specific Wi-Fi bands.

Here are some suggestions to troubleshoot this problem:

• Firmware Update: Ensure your WEB660S is running the latest firmware version. Outdated firmware can sometimes lead to performance issues or unexpected behavior. You can typically find the latest firmware on the Zyxel support website by searching for your product model. If you are already on the latest firmware, consider if the issue started after a recent update. Some users have reported issues with specific firmware versions on other Zyxel devices leading to degraded performance, particularly with upload speeds.

• Isolate the Issue:

  • Test with a single client: Connect only one device to the WEB660S via Wi-Fi and conduct speed tests when the upload speed degradation occurs. This can help determine if the issue is client-specific or a broader AP problem.
  • Wired vs. Wireless: Since your WEB660S is connected to a 10Gb wired network, perform speed tests directly from a wired device connected to the same Mikrotik router to confirm the upstream network performance remains consistent.

• Check for Interference: Although you've tried disabling 2.4GHz and 6GHz, consider using a Wi-Fi analyzer tool to check for channel interference from neighboring networks, especially on the 5GHz band where the bulk of your speed should be. High channel utilization can significantly impact performance.

• Power Supply: Ensure the power supply for the WEB660S is adequate and stable. Unstable power can sometimes lead to intermittent performance issues.

To further assist you, please provide the following information:

• Current Firmware Version: What is the exact firmware version installed on your WEB660S?
• Network Topology Map: A simple diagram showing how your WEB660S, Mikrotik router, and other relevant network devices are connected.
• Speed Test Methodology: What speed test service or application are you using, and are you testing to a local server (e.g., OpenSpeedTest) or an external internet server? Some speed test tools might show discrepancies.
• Nebula Management: Is your WEB660S managed by Zyxel Nebula Cloud? If so, please enable Zyxel Support Access via Help > Support Request in your Nebula console and provide your Organization or Site name. This will allow our support team to remotely view your cloud environment configuration, which can significantly expedite troubleshooting.