Re: 802.11 k/r/v support in wpa_supplicant

Could I get some information about support of 802.11k/r/v standards is
wpa_supplicant?
* What part of 802.11k/r/v standards are implemented and since which
revision of wpa_supplicant?

[Dennis] Most of 802.11k/r/v was implemented in wpa_supplicant 2.6, but many
important bugfixes have been added since then.  For example, you would
want to use 802.11r with the WPA KRACK patch implemented in 2018.

* What is wpa_supplicant responsible for and what part of those
standards supplicant expects that nl80211/cfg80211 driver is
responsible for?

[Dennis] This is dependent on the driver implementation.  It is possible for
wpa_supplicant to take care of 802.11r roaming (scanning, roaming, and
key management) if supported by the STA chipset driver/firmware.
wpa_supplicant can also respond to 802.11k/v requests by the AP, if
the STA driver allows it.

* Is 802.11r typically implemented in wpa supplicant or in driver level?

[Dennis] 802.11r key management is usually done in middleware (e.g.
wpa_supplicant), but scanning/roaming may be done by the driver or
wpa_supplicant - depending on the driver implementation.

* Does supplicant takes into account 802.11r NeighborReport response
and/or 802.11v Load Balancing message from AP during roaming?

[Dennis] wpa_supplicant does not act on Neighbor Report results to reduce scan
time - this additional functionality is implemented by the OEM.
wpa_supplicant may act on an 802.11v BSS Transition Management
request, but it depends on a variety of factors, such as current RSSI
and if Disassociation Imminent was set.

* May I ask your your opinion what advantage of those standards are
for not-mobile station i.e STB?

[Dennis] Load balancing is useful for fixed stations within range of multiple
APs.  Using 802.11k, the AP controller identifies a load-balancing
optimization.  Then, using 802.11v BTM, the AP can request STAs
(especially sticky STAs) to move from an overloaded AP to a better AP.
The STA can then use 802.11r to seamlessly move to the requested AP
channel without disrupting any time-sensitive streaming applications.