[ath9k-devel] ath9k (ad-hoc?) problems in compat-wireless trunk as of sept 6/2

["Nicolás Echániz" <nicoechaniz@altermundi.net>]

We are testing current wireless in QuintanaLibre and we are finding some strange behaviors.

The first symptom we have been able to reproduce is this:

Given nodes A and B which are neighbors with a good link quality (-68 signal, 15Mbps throughput) and a third node C which has a comparable link to A and a low signal link to B. When we turn of C's wireless the latency between node A and B will be extremely high (in the thousands of ms) for almost one minute.

In this example, nodes A and B are marisa and nogal. And node C is gerylu (which we turn off 200 sec after the ping starts).

http://pastebin.com/MzWSCDRb


the moment when the ping times return to normal is coincidential with the iw event (as seen from marisa -Node A- ):

wlan0 (phy #0): connection quality monitor event: peer 92:f6:52:c6:00:ed didn't ACK 50 packets
wlan0: del station 92:f6:52:c6:00:ed

92:f6:52:c6:00:ed   <-- this is gerylu (node C)


We are observing an overall instability in the network which consists of 40 nodes (100% ad-hoc) some of which hear up to 16 neighbors in the "iw station dump", so this scenario may be occurring frequently.

Lastly, we also observe that some nodes are not associating on one of their interfaces (they are dual band), although they did associate correctly before the upgrade.



We will keep some nodes with this version for a couple of days in case someone (Felix?) want's to log in and do some live testing.

Guido will add some more info from the tcpdumps we collected if it's relevant.


Cheers,
Nico