On Thu, 2010-12-09 at 13:15 -0800, Tim Harvey wrote: > The 802.11 spec states that the STA that generated the last Beacon frame shall > be the STA that response to a probe request. This is important for congestion > reduction when a probe request is received - only 1 node in an adhoc BSS > will transmit a response. While mac80211 drivers should provide the > tx_last_beacon function to report if they transmitted the last beacon many > do not. As an attempt to reduce probe response congestion default this > to 0 such that a node not implementing this capability does not contribute > to unnecessary congestion. > > In a modern medium sized office environment I see upwards of 100 probe > requests per second received at a given node from various hardware/OS/drivers > doing zeroconf 'active probing' as opposed to passively listening for beacons. > With a modest 10-node adhoc network consisting of drivers that do not implement > this tx_last_beacon feature, I have seen this result in the simultaneous xmit > of probe responses accumulating to 500 probe responses per second because of > collisions which brings the adhoc network to its knees as well as causes > needless congestion. FWIW, I'm OK with this. It shouldn't really have much adverse effect. johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
