Closed silverjam closed 10 years ago
Another relevant email excerpt:
* Beacon frame content:
- According to the standard, the default BasicRateSet shall be used as BasicRateSet.
However, we often observe only 1 MCS is set as BasicRateSet when 2.4GHz channel is used.
We see BasicRateSet is set appropriately sometimes.
- HT related elements are not included.
@jcard0na & @silverjam any guideline for the wpa_supplicant.conf support on this?
I initially thought that the problem was that we were hard coding the Basic Rate Set to be the default Basic Rate Set for Enhanced Rates PHY (ERP) (i.e. https://github.com/cozybit/wpa_s_mesh_android/blob/latest_mesh_enabled/wpa_supplicant/mesh.c#L165 . This is why I had suggested to move this to the config file.
But based on the report, it seems that the problem is that "we often observe only 1 MCS is set as BasicRateSet when 2.4GHz channel is used", or, in other words, that the Basic Rate Set is incorrectly set.
Just for background, the Basic Rate Set are the rates that must match between two peer candidates in order to peer with each other. They are "marked" as belonging to the BSSRateSet by setting the Most Significant Bit on the rate that are included in the Supported Rates and Extended Supported Rates Information Elements.
This is not a problem with hwsim (see attached capture, the default ERP rates are marked with a red dot, and have the MSB correctly set).
Could this be a driver issue?
Regarding the absence of the HT oper IE, I think it should be tracked in a separate issue.
I've logged a separate issue for the HT rate support https://github.com/cozybit/wpa_s_mesh_android/issues/29
Further comment from email:
> > Do you have more information on when and how often this happens? Or
> > do you have a packet capture of this that you could share?
>
> Indeed, our feedback above was slightly incorrect.
> We see that beacon frames announces only 1 MCS as BasicRateSet. On the other hand, Mesh Peering frames announces default BasicRateSet appropriately.
> For your information, kernel implementation also announces only 1 MCS as BasicRateSet.
Beacons and mesh mgmt peering frames appear match with respect to rate sets.
Beacon frame
Mesh action frame