2,4 GHz not working on some Extreme Network AP3915i

Installing and Using OpenWrt
1

Hi,

I've got a few Extreme Network AP3915i and I noticed that some were not able to work with the 2,4 GHz chip, while others worked just fine. Although there are differences in hardware revisions (v1.00 and v.1.10), this does not determine the state of the 2,4 GHz chip. 5 GHz is working fine on all of them.

I tried multiple firmware versions (23.05.5, 23.05.0 and 23.05.1), but always the same outcome:

  • 2,4 GHz networks not showing up for clients, although web UI acts like it's there
  • 2,4 GHz wireless network scan does not work from UI, does find anything
  • doesn't matter if a 2,4 GHz gets configured or if just the basic OpenWRT network gets activated

Since I've got some working APs with hardware revision v1.0 and some non-working with the same revision, I suspect this is not the problem.

dmesg does not show any errors related to this (and nothing more than the output from the working ones, so it seems like OpenWRT thinks it's working).

Does anyone have any idea about this?

Thanks in advance!

2

Sounds like antenna absent?
Could you share ubus call system board from 23.05.5 (certainly not .4) and /etc/config/wireless (cleaning last half of MAC and IP addresses and nullifying any passwords)

3

ad antenna: they're physically on the device and soldered and glued to the board, looks the same as other working APs too.

output from bus call system board:

{
        "kernel": "5.15.167",
        "hostname": "OpenWrt",
        "system": "ARMv7 Processor rev 5 (v7l)",
        "model": "Extreme Networks WS-AP3915i",
        "board_name": "extreme-networks,ws-ap3915i",
        "rootfs_type": "squashfs",
        "release": {
                "distribution": "OpenWrt",
                "version": "23.05.5",
                "revision": "r24106-10cc5fcd00",
                "target": "ipq40xx/generic",
                "description": "OpenWrt 23.05.5 r24106-10cc5fcd00"
        }
}

content of /etc/config/wireless:

config wifi-device 'radio0'
        option type 'mac80211'
        option path 'platform/soc/a000000.wifi'
        option channel '1'
        option band '2g'
        option htmode 'HT20'

config wifi-iface 'default_radio0'
        option device 'radio0'
        option network 'lan'
        option mode 'ap'
        option ssid 'OpenWrt'
        option encryption 'none'

config wifi-device 'radio1'
        option type 'mac80211'
        option path 'platform/soc/a800000.wifi'
        option channel '36'
        option band '5g'
        option htmode 'VHT80'
        option disabled '1'

config wifi-iface 'default_radio1'
        option device 'radio1'
        option network 'lan'
        option mode 'ap'
        option ssid 'OpenWrt'
        option encryption 'none'

This is on a freshly flashed and reset device, the only thing I did after a login in the web UI was enabling the default 2,4 GHz network called OpenWrt (which did not work).

4

I've got four of them, but I don't remember having any issues with the 2.4G radio.

This device could also be supported by the generic Extreme Networks WS-AP391x build. You might want to try that (snapshot only): https://firmware-selector.openwrt.org/?version=SNAPSHOT&target=ipq40xx%2Fgeneric&id=extreme-networks_ws-ap391x

NB: I never tested this build, although it might make sense to drop the 3915 build if the 391x build works fine. There are some caveats, make sure to read the commit message at https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=74e7f8ebbdc19c58ac59c792154041a6b3c124f5

Please also post a complete boot log, maybe the firmware expects different WiFi calibration files.

5

Thank you for the suggestion. I tried flashing the 391x firmware snapshop, but it seems it bricked the device for now. Will try to flash correct firmware again later, shouldn't be a problem with TFTP or serial console.

6

It wasn't bricked, just the WAN/LAN ethernet interfaces were not configured correctly, can be fixed via serial console.

AP is booting now, but the same thing happens here: no wifi scan on the 2,4 GHz chip is possible, but 5 GHz works perfectly fine.

Output of iw phy | grep Antenna was the same as on a working AP, by the way, so it seems, all antennas are there.