That's interesting, because you've identified the reason I asked the question - on my TP-Link router wired connections just flood out wireless connections, and make them unusable as long as I'm doing anything heavy (like downloading ISOs).

The solution's not going to be found in the firmware, is it?

Yes, in general, having a better router would probably help (although you haven't mentioned the exact model you have, maybe it's already fine and the problem is elsewhere).

Enabling SQM [1] would probably mitigate the issue further, at the cost of requiring more processing power.

[1] https://openwrt.org/docs/guide-user/network/traffic-shaping/...

I didn't want to bog HN down in doing my tech support for me, but since you ask it's a TP-Link AC1200 (https://www.tp-link.com/uk/home-networking/wifi-router/arche...). I'm not doing anything meaty with it most of the time.

I found this to be completely unnecessary when I moved to a 100Mbit symmetrical connection. Not sure if its the higher speed or having a better upload channel, but I completely got rid of all QoS/traffic shaping on my router and never felt the need to turn it back on.

The need for aqm is dependent on the status quo. Most providers nowadays use red/pie in the last mile and buffers-inducted delay rarely exceeds 100ms; much less so when it became clear that flow-queueing would be required and possible. Also multiple queues with codel on them have found their way into some wifi stack’s to deblot this access layer