Pi 3B+ Access Point: a bit temperamental

[audetto]

I have setup a Pi 3+ as an access point following this

https://www.raspberrypi.org/documentati ... -routed.md

It works pretty well... until it doesn't.

I am not talking about the whole routing bit, but simply the link between the pi and the wifi clients.
Some clients (a chromecast) are very stable, others (tablet, phone) seem to loose connection after a while in the sense that they cannot be ping'ed from / to the pi.

Like they went to sleep and they don't wake up or it takes something to wake them up.
Normally after I switch off / on their network, they start again.

According to hostapd they are still connected, since this line is *not* present in the log

May 01 21:30:04 raspberrypi hostapd[445]: wlan0: STA 11:22:33:44:55:66 IEEE 802.11: disassociated

until after I switch off the wifi on the device.

Of the various services involved I run

NO wpa_supplicant.service
YES dhcpcd.service
YES hostapd.service
YES dnsmasq.service

I have configured OpenWRT which seems more stable, no drop off, but I'd like to see if I can run a normal raspbian with the extra access point enabled.

[audetto]

Answering my own email.

I vote for some sort of sleep / low power mode.

The chromecast has a stable ping time of < 2ms.
The samsung galaxy anywhere up to 1500ms and sometimes it just does not answer.
Then I do something on the tablet and it starts to reply at very variable times (1-1500).

It is just super annoying to debug as you never know if it does not works or it has decided to sleep...

[audetto]

Continuing with my journey,
I feel (without strong evidence) that on the 5Ghz band the Pi works better as AP.

I have used the same hostap.conf file that OpenWRT uses by default on the Pi

Things are not perfect, but looks more stable.
Been trying to figure out how to select the best 5Ghz channel and it is not as clear as for 2.4

By ISP router uses a big range from 36-50 and the Pi cant broadcast outside this range, so they are basically 100% overlapping.
Nothing like 1 6 11 for the old systems.
How is this supposed to work in a congested environment (which I do not have as I live in "countryside")?

Code: Select all

driver=nl80211
logger_syslog=127
logger_syslog_level=2
logger_stdout=127
logger_stdout_level=2
hw_mode=a
beacon_int=100
channel=36


tx_queue_data2_burst=2.0
ieee80211n=1
ht_coex=0
ht_capab=[HT40+][SHORT-GI-20][SHORT-GI-40][DSSS_CCK-40]
vht_oper_chwidth=0
vht_oper_centr_freq_seg0_idx=38
ieee80211ac=1
vht_capab=[SHORT-GI-80][SU-BEAMFORMEE][MAX-A-MPDU-LEN-EXP0]

interface=wlan0
ctrl_interface=/var/run/hostapd
ap_isolate=1
bss_load_update_period=60
chan_util_avg_period=600
disassoc_low_ack=1
preamble=1
wmm_enabled=1
ignore_broadcast_ssid=0
uapsd_advertisement_enabled=1
utf8_ssid=1
multi_ap=0
wpa_passphrase=.....................................
auth_algs=1
wpa=2
wpa_pairwise=CCMP
ssid=................................
bridge=br-LAN
wpa_disable_eapol_key_retries=0
wpa_key_mgmt=WPA-PSK
okc=0
disable_pmksa_caching=1
bssid=...........................