GL-AXT1800 (4.8.3): ping to router jumps to 100-200 ms every 5 minutes after client association

Router
1

Device: GL-AXT1800 (Slate AX), firmware 4.8.3. Router mode, WAN on Ethernet (eth0). Repeater (STA) disabled.
Client: Linux laptop (Manjaro, NetworkManager), 5 GHz SSID on wlan1, channel 48, HE 80 MHz, NetworkManager signal 80%.

Problem
Ping from the laptop to the router LAN address (192.168.8.1) is normally 1-3 ms. Every 5 minutes, latency goes up to 100-200 ms for 1-3 seconds. There is no packet loss. The router log (logread, kernel log) shows no entries at these times.

The timer starts at client association
I measured with fping -D -c 660 -p 1000 192.168.8.1, one ping per second.

Association Spike +5 min Spike +10 min Spike +15 min
13:29:40 13:34:45 13:39:47 -
14:46:46 14:51:48 14:56:53 -
08:04:54 08:09:54 08:15:01 08:20:09

What I tested (no change, spikes stay every 5 minutes)

  1. Router reboot (uptime was 52 days).
  2. Fixed 5 GHz channel 48 instead of Auto.
  3. Repeater disabled. Repeater status track set to Low data. Ethernet track is Low data.
  4. Laptop Wi-Fi power save off (iw dev wlp3s0 set power_save off).
  5. wireless.default_radio0.max_inactivity=600. hostapd config showed ap_max_inactivity=600, but spikes still came at +5, +10 and +15 min. I reverted this change.

Comparison
The same laptop on a different router (5 GHz, channel 36) shows no spikes in 11 minutes: max 21 ms, 660/660 replies.

Questions

  1. Does the Qualcomm Wi-Fi driver or firmware run a per-client task every 300 seconds? Examples: rate control, station statistics, or a background scan.
  2. Is there an option to disable it or to change its interval?

I can run more tests or send a full log export.

3

Hi,

Thank you for the information.

Since we haven't been able to reproduce the periodic latency spikes in our local tests.
Could you help us check whether the Wi-Fi signal strength (RSSI) changes when the issue occurs?

While your Linux laptop continuously pings the router's LAN IP, please connect to the AXT1800 via SSH and run the following command to monitor the Wi-Fi client information:

while true; do
  date '+%Y-%m-%d %H:%M:%S'
  iwinfo wlan1 assoclist
  sleep 1
done

Please check whether the RSSI changes significantly when the ping latency rises to 100–200 ms.

4

Hi,
Thank you.
I ran both commands at the same time for 15 minutes (fping 1/s to 192.168.8.1, iwinfo wlan1 assoclist 1/s via SSH).

Result: the RSSI does not drop when the latency goes up. In 2 of 3 spikes it is 5-8 dB stronger.

fping: 900/900 replies, 0% loss, max 165 ms. Spikes again every 5 minutes: 08:34:04, 08:39:12, 08:44:17.

Spike Ping (ms) RSSI before RSSI during spike Rate (RX/TX)
08:34:04-09 75-133 -52 dBm -45 to -49 dBm HE-MCS 9 / 8-9, no change
08:39:12-15 72-165 -55 dBm -46 to -57 dBm HE-MCS 11 / 9-10, no change
08:44:17-20 105-150 -57 dBm -50 to -55 dBm HE-MCS 10-11 / 8-9, no change

RSSI over the whole 15 minutes: -61 to -44 dBm, most samples -57 to -53 dBm (SNR about 50). 7 of the 10 strongest samples (-47 dBm or better) are inside the spike windows. The MCS rate
does not go down during the spikes.

So I think signal strength is not the cause. I can send both raw log files if needed.

5

Hi,

Sorry for the late reply and thank you for your testing and feedback.

Could you please share your AXT1800 with us via GoodCloud so that we can investigate the issue remotely? Please follow the instructions in the guide below:

Please also enable Remote Web Access (GUI) and Remote SSH on your router.

After the sharing, please send us your router's MAC address, temporary admin password, and the Ping and Wi-Fi monitoring logs via private message.

Thank you for your understanding and support.

How to send private messages:

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