Hi Community,
There are similar variables in wpa_supplicant to limit peers or stations:
- max_peer_links for 802.11s mesh
- max_num_sta for AP mode (maybe P2P_GO? I do not know)
wpa_supplicant source code and data structures are daunting to me,
although I worked on its source code for P2P about 1.5 years ago.
Can anyone point to me what functions I can change to add a variable
(similar to max_peer_links or max_num_sta), with the purpose to limit
the number of peers for IBSS/adhoc? Probably we do not need to start
4-way handshake once associated stations reach max_peers for IBSS?
Thanks a lot.
Xuebing Wang
On 2017年06月03日 12:09, Xuebing Wang wrote:
Hi community,
This email is mainly addressed to hostap/wpa_supplicant mailing list.
Descriptions of my issue:
- I am establishing IBSS/adhoc network using OpenWRT 15.05 + ath9k
(AR9331).
- When nodes are relatively closely placed, the peers (the term is
'neighbors' in batman-adv mesh) reach 40, ath9k driver detects "tx
hung, resetting the chip" (for RESET_TYPE_TX_HANG).
- This ath9k "tx hung" randomly happens among the 40 nodes (in adhoc
network), and it happens relatively often (seemingly randomly for
nodes), and randomly makes some nodes un-usable.
- This appears to be an issue with ath9k kernel driver or ath9k
hardware that it can not handle ~40 peers.
- IBSS/adhoc with 20 peers work well.
Is there a config in wpa_supplicant that we can limit the number of
peers?
In the other words, once the number of peers ('iw wlan0 station dump')
reaches a pre-configured number (e.g. 12 or 16), wpa_supplicant does
not authenticate any more, for IBSS/adhoc only?
- A subtle detail: once a new beacon with higher RSSI is detected, the
current connection with lowest RSSI will be de-authenticated, and to
authenticate this new peer (with higher RSSI in beacon).
Is this "limiting number of peers for IBSS/adhoc" a good work-around
for 40+ peers adhoc network, although the ultimate root cause
seemingly is with ath9k kernel driver or ath9k hardware?
Also, if there are many (like 40+) peers in IBSS/adhoc network, I am
not sure how medium access contention and collisions factor in, for
management frames?
Here is my wpa_supplicant conf file:
------
ctrl_interface=/var/run/wpa_supplicant
# use 'ap_scan=2' on all devices connected to the network
# this is unnecessary if you only want the network to be created when
no other networks are available
ap_scan=2
network={
ssid="Net-xxxxxxxx"
mode=1
frequency=2462
proto=WPA2
key_mgmt=WPA-PSK
pairwise=CCMP
group=CCMP
psk="xxxxxxxx"
}
------
Another approach could be to use user-space shell script to "iw <dev>
ibss leave" for the lower RSSI stations?
- As I am using batman-adv to build mesh network on the top of
IBSS/adhoc, a similar approach can be done at batman-adv level.
Suggestions?
Thanks.
Xuebing Wang
_______________________________________________
Hostap mailing list
Hostap@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/hostap
