Additional beacon being sent after last CSA beacon

jfollas
Posts: 9
Joined: Sun Oct 18, 2015 1:23 pm

Additional beacon being sent after last CSA beacon

Postby jfollas » Tue Feb 07, 2017 9:24 am

I recently discovered that the ESP8266 (SDK 2.0.0) broadcasts Channel Switch Announcements (defined in 802.11h) when the STA connects while in STATIONAP mode and the STA channel is different than the already-running SoftAP channel. However, looking at Wireshark logs, I see that there's an additional beacon being sent after the channel change is supposed to have taken place.

I don't have proof yet, but I think this may be preventing some STAs from following the channel switch. In particular, I have been trying to troubleshoot why Android devices seem to wait on the old channel instead of moving to the SoftAP's new channel, and this stray beacon may be the reason.

Example:

Code: Select all

SN      SSID           CurrChan   CSA
=====   ============   ========   ========
1058    ESP_1BEB89     9
1062    ESP_1BEB89     9          Mode: 1, Number: 4, Count: 3
1064    ESP_1BEB89     9          Mode: 1, Number: 4, Count: 2
1066    ESP_1BEB89     9          Mode: 1, Number: 4, Count: 1
1068    ESP_1BEB89     9
(then no more beacons because the switch occurred)

jfollas
Posts: 9
Joined: Sun Oct 18, 2015 1:23 pm

Re: Additional beacon being sent after last CSA beacon

Postby jfollas » Wed Feb 08, 2017 8:17 am

Possible related bug (maybe it's a feature request?):

wifi_set_channel() does not have any impact when the SoftAP is running (i.e., when the Station is disconnected).

My hope would be to use wifi_set_channel() to cause a Channel Switch Announcement to be issued so that all of the connected STAs would not be deauth'd. Right now, the only way to change the channel seems to be to call wifi_softap_set_config, but that results in a deauth/disassociate as the SoftAP shuts down (just to start back up again with the same SSID/PSK).

RiliyVax
Posts: 3
Joined: Sat Apr 29, 2017 1:03 pm

Additional beacon being sent after last CSA beacon

Postby RiliyVax » Tue May 02, 2017 9:38 am

I can send a template using a filter rule. However if the template has html format then it will be sent without it.

Why the filter rule send plain text only? Is it a bug or what?

Thanks.

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