Re: [PATCH] add AllowRoaming station property

[James Prestwood <prestwoj@gmail.com>]

Hi,

On 10/20/23 7:57 AM, Denis Kenzior wrote:
> Hi Pedro,
> 
> On 10/19/23 06:55, Pedro André wrote:
>> Hi Denis,
>>
>> First of all, thank you for your feedback.
>>
> 
> No worries, I'm a bit swamped these days so my responses are sometimes 
> delayed. Just FYI.
> 
>>
>> There is a use case where a device can be connected to an infrastructure
>> AP and hosting its own AP. In this specific case it would be ideal to
>> disable roaming since swapping the infrastructure AP can lead to
>> instability on devices connected to the AP being hosted. In this case,
>> the device should act as if it is not able to roam, so I was under the
>> impression it would be OK to not honor AP directed roaming.
> 
> So AP directed roaming is a bit of a unicorn.  I haven't really seen it 
> used in practice.  However, when it is enabled, it is usually pretty 
> aggressive.  If you don't honor the roam request you will likely get 
> disconnected.  Don't know if this impacts your design.

Just my two cents. I do see it used in our deployments, but the APs 
never seem to set the "disassociation imminent" bits so IWD will still 
decide if it should roam or not.

Btw hostapd has 3 separate CLI commands for transition management: 
DISASSOC_IMMINENT, ESS_DISASSOC, and BSS_TM_REQ.

The BSS_TM_REQ won't set the imminent bits unless additional options are 
passed so it wouldn't surprise me if nearly all APs leave those bits 
unset :)

I think its very unclear what the intent is of the AP sending the 
transition request. It likely sends identical frames regardless of the 
circumstances whether its "I am a bit overloaded, please leave" or "I'm 
shutting down leave immediately".

Thanks,
James