Performance Degradation: Reduced Connected Devices/WIFI speed After Adding New Features

[Amicah-cyber]

Description:
After adding several new features to the elimupi AP setup, including Squid, OpenVPN, an additional NGINX virtual hosts, new F-Droid applications and update of fdroid server, the maximum number of supported connected devices dropped from 13 to 6.

Expected Behavior:
The system should maintain at least the previous performance level, supporting 13 connected devices.

Actual Behavior:
The number of supported connected devices has significantly decreased, impacting performance.

Possible Causes and Next Steps:

1. Need to measure CPU, RAM, and temperature usage.
2. Potential network congestion due to additional services.
3. Possible interference or bandwidth constraints.

Ideas for Solutions:

1. Metric Collection – Yes, adding a tool like htop, nmon, or glances to monitor CPU, RAM, and temperature will help identify resource bottlenecks.
2. Bandwidth Analysis – Tools like iftop or nload can check if Squid, OpenVPN, or other services are consuming too much bandwidth.
3. QoS (Quality of Service) – Implement traffic shaping with tc (Traffic Control) to prioritize AP traffic over background services.
4. Network Optimization – Consider switching to a USB WiFi adapter dedicated to either the AP or the upstream connection.
5. Reducing Overhead – Optimize OpenVPN settings, disable logging where unnecessary, and ensure services aren’t running more than required.

[ltoning]

@Amicah-cyber does this happen on latest Elimupi 4.1.1 release?

The firmware that's enabled on the OS debian bookworm should support max 19 clients.
https://github.com/RPi-Distro/firmware-nonfree/tree/bookworm/debian/config/brcm80211/cypress

[ltoning]

Did some testing on latest Elimupi 4.1.1 and was able to connect 10 clients and still have an abilty to browse the internet and the local services. I have no more devices to connect to extend >10 clients.

root@elimupi:~# hostapd_cli status Selected interface 'uap0' state=ENABLED phy=phy0 freq=2447 num_sta_non_erp=0 num_sta_no_short_slot_time=0 num_sta_no_short_preamble=0 olbc=0 num_sta_ht_no_gf=0 num_sta_no_ht=0 num_sta_ht_20_mhz=0 num_sta_ht40_intolerant=0 olbc_ht=0 ht_op_mode=0x0 cac_time_seconds=0 cac_time_left_seconds=N/A channel=8 edmg_enable=0 edmg_channel=0 secondary_channel=0 ieee80211n=0 ieee80211ac=0 ieee80211ax=0 beacon_int=100 dtim_period=2 supported_rates=02 04 0b 16 0c 12 18 24 30 48 60 6c max_txpower=20 bss[0]=uap0 bssid[0]=e6:5f:01:5f:a5:05 ssid[0]=elimu num_sta[0]=10

[Amicah-cyber]

A few things to note:

1. The device allows multiple connections up to 13 devices; however, there is a lag when accessing content from the elimupi. For instance, when accessing the default virtual host start.elimupi.online, it takes a few minutes to open. This might be due to heavy network traffic.
2. Second: Attempting to create a bullseye image from the current code fails due to lack of updated apt repositories, which results in dependency conflicts when the repos are updated with custom debian repos.

Currently checking on the issue and network traffic using the new image 4.1.1.

[Amicah-cyber]

@ltoning Another test on 14 devices using the new image 4.1.1 was successful. No issue was observed. I also increased the distance between the AP and the devices to check if the issue was caused by distance, but it appears not. My conclusion would be, it was an issue with the prior image 4.1.0 used to prepare the Elimupis for new schools that came on board in January and early February.
I will keep you updated in case this issue resurfaces. Hopefully it won't.