We are developing an education-related solution and I would like to know if anyone had any insight here.
Question: We would like to find out how many simultaneous users OpenWRT could handle on the pi 4b with reasonable performance. They would also be connecting via WIFI most likely if that mattered.
Could anyone shed some light on this? Thank you very much.
Wifi is unstable a best to my knowledge so I wouldn't recommend going that route
You never defined ISP speed or what client acceptable speed is.
That wifi is built as a receiver and not a transmitter so you should have a real AP to really have any client support.
But you have Gbit connector on Pi4 so at best 100 users with 10Mbit/client is one theoretical solution. Dnsmask can handle 150 clients if I remember right.
But my experience is that everyone wants 30-40Mbit/s to be happy or else it is faster to surf over 4G.
But I would say about 20 clients/Gbit internet line for them to be satisfied. But not everyone uses full bandwith all the time so is is a complex question.
I wouldn't expect the brcmfmac wireless of the RPi to support more than (quite literally) a handful of users. on-chip RAM of these fullmac wireless chipsets is limited and rarely exceeds space for 4 or 8 connected STA(tion)s (under ideal circumstances, without roaming).
Is there a wifi card (something that plugged into the board) that would operate as an access-point I could get that you have experience with that would provide better range and performance (simultaneous connections)?
Whatever solution we made had to be cost-effective and preferably with everything contained "in the box."
Thanks for your help. Also, acceptable speed would be whatever allowed "browsing webpages" may be a little in-page video, not games or movie-streaming or anything.
I don't think there is any useful direct plug in the pi board or dongle that would do a decent job.
As was said, I think your best bet is to find some (possibly on hand and free?) cheap older WiFi routers that could be used as dumb AP's bridged to the Pi. See: https://openwrt.org/docs/guide-user/network/wifi/dumbap
You then get decent radios with full sized antennas, for good range, flexibility in placing them in better positions away from your main router for even better range, and if the prospective AP box is an ath10k or mt76(?) you would get some of the cutting edge wifi airtime fairness and queueing advances available by also running them on OpenWrt.
Shopping around might find you some bargains, a while back I could buy new TL-WR841N's (300mbit, N wifi) for $20. You might want something faster nowadays... Check what you might have laying around, vs the compatiblity list, and check the ongoing "good cheap OpenWrt router" threads...
Thank you for taking the time to write. I really appreciated your help.
Look at MT7621 boxes like the GL-MT1300. It's the same price or less than a Pi + case + wifi adapter, and the wifi will be vastly better since their wifi chips are on a PCIe bus.
There's an alternative binary firmware that bumps this number up by sacrificing some features (for example, dropping the ability to operate in DFS channels), but it's still not particularly high...
GL-AR750S has better wifi in my opinion, but its CPU isn't exactly stellar and the microUSB power connector is fragile garbage.