I have a large home network with 323 Wifi clients, most of them 2.4 GHz IOT clients on one SSID.
Due to lack of Ethernet wiring, I use a mesh network. When using Ubiquiti stock firmware, I have run into association limit problems - the wired AP's max association limits got exhausted by the IOT clients, sometimes preventing the downlink mesh APs from connecting at all.
The association limit I have run into appears to be about 120 clients per AP, far less than what Ubiquiti advertises in their specs. I just installed OpenWRT on a single NanoHD I'm no longer using, and I'm hitting this limit as well - 122 associations to be exact. Clearly there is an upper threshold that must be 7 bits.
Is this actually actually a hardware limit, or is there a possibility that one might be able to raise the limit by modifying the driver ?
Jokes aside, those numbers are insane - from a mere airtime point of view already. There is quite some management traffic necessary to keep STAs connected, which needs to be done at the lowest base rate - which leaves you with a finite amount of physical airtime left for actual traffic, before even thinking about channel utilization from your neighbours and the special requirements for sleeping clients - and of course the chipset's/ firmware's/ driver's limits.
So what can you do?
wired ethernet (fibre/ copper( wherever possible
reduce the number of clients (by an order of magnitude!)
ax greenfield mode (raising the bar for the lowest base rate that is needed for management traffic), but this will exclude many IoT devices, so probably not an option
more APs, lower transmit power, optimized distribution between APs, channels, etc.
just fore reference, others are complaining about a 32 STA limit for ath10k-ct already…