I'm new to openwrt, but I want to build an SBC wireless bridge (wireless access point). Doesn't have to be Rpi, but maybe Okta. How many concurrent users can I expect to support? I need to build for 30-40 users, not necessarily doing heavy traffic.
I read somewhere that 19 users was a limitation on the Rpi? Can I add more SBCs, then, to cover a large office space with the same ssid?
I have a bunch of Cisco AP that I just want to throw out;)
Are you asking about how many client devices can connect to a Raspberry Pi's wifi subsystem? Simply put, don't bother.
There may be some other SBCs that have better wifi solutions, but the Raspberry Pi (all generations to date) have truly terrible wifi chipsets. Because of the 1x1 radio arrangement and small PCB antennas, they are easily outperformed by any purpose-built AP or all-in-one wifi router in range, speed, and client count. Pis also don't support simultaneous dual-band operation with the built-in hardware
Adding a USB wifi adapter may provide some improvement, but you're still far better off with a real AP, as most of the USB devices are also fairly poor in the same ways as the built-in wifi (small antennas,1x1 or 2x2 radios, and some don't even support AP mode which would be an obvious blocker).
The Pi4 (and several other SBCs) make excellent wired routers, but stay away from the wifi.
As other mentioned, RPi's WiFi isn't meant for this purpose due to hardware design, you can think about getting like GL-INET MT1300 and flash vanilla OpenWrt on it, currently I am having it as well and occasionally I use it in hotel with WiFi as WAN which works OK for me.
The rpi isn't the ideal candidate from a price point perspective, unless you already own one.