Does station<->station communication get forwarded over the AP? [WIFI-2280]

[Dumbledore]

Heya!

I have a mesh of 3-4 boards - one working as an AP, the other ones as stations connected to that AP.
For some reason, communication between stations is much slower than communication between station and AP, so I was thinking that maybe all station<->station communication gets forwarded over the AP?

If that's the case, is there any way to turn off that behavior? This would defy the purpose for me since I specifically want to measure the CSI from the channels between all boards.

Thanks in advance!

[ESP_Sprite]

Not sure, but that may be a setting in the access point (some disable station<->station communication).

[Dumbledore]

Hi,

I'm using another ESP32 board as an AP. Do you know if there's an API addressing this issue, e.g. a switch to turn station<->station communication on/off?

Thanks in advance.

[ESP_Alvin]

Moderator's note: edit the topic title for issue tracking, thanks.

[liuzhifu]

Hi Dumbledore,

Yes, station <-> station communication depends on AP forwarding. If we disable AP forwarding, station <-> station communication is broken, I'm not sure this is what you expected.

Moreover, currently we have no API to disable AP forwarding.

[Dumbledore]

Thanks for the reply, that's unfortunate.

I really like the ESP32 board's ability to directly output CSI via the associated callback function, however, right now it's not very practical to use. The only way to measure CSI between multiple ESP32 boards is by sending packets via UDP or TCP (the esp_wifi_80211_tx API isn't triggering the CSI callback), that is, the boards have to be in a shared WiFi. Therefore the only way to get CSI from all channels between more than two boards is Station<->Station communication - and it seems like this won't work, too, since I'm always only really measuring the channels from AP to the others because of AP forwarding.
Fixing one of both (the forwarding issue or letting the boards get CSI from raw packets, without the need to be in the same WiFi) would be enough already.

[liuzhifu]

Hi @ Dumbledore,

`Therefore the only way to get CSI from all channels between more than two boards is Station<->Station communication - and it seems like this won't work, too, since I'm always only really measuring the channels from AP to the others because of AP forwarding.`

How about using ESP32 Station <-> ESP32 AP topology?

[liuzhifu]

Hi,

Could you explain "the esp_wifi_80211_tx API isn't triggering the CSI callback" in detailed? Could you help to provide following info:

1. How to use esp_wifi_80211_tx
2. How to encapsulate the WiFi raw packets
3. The mac address of all your STA/AP

Then we can check what's wrong in your code.