Fast roaming with mac80211 drivers

Divinsky, Yonatan yoni.divinsky at
Sun Dec 18 09:38:32 EST 2011

On Sun, Dec 18, 2011 at 4:26 PM, Jouni Malinen <j at> wrote:
> On Sun, Dec 18, 2011 at 03:34:30PM +0200, Divinsky, Yonatan wrote:
>> I am trying to test the fast roaming with a mac80211 based driver,
>> but I see that the whole roaming process takes about 200ms, even
>> when working in an open netwrok.
> How do you test this and how exactly do you measure that 200 ms?

I'm not testing the 80211r yet, because I am first trying to do roaming
between 2 open APs on the same network.

To test it I set two APs with the same SSID.
I connect to AP1
I simulate voice traffic using iperf:
iperf -c -b83200 -l208 -S224 -t120

Then I lower the RSSI of AP1 so after a bgscan I roam
to AP2.

Then using a sniffer captrue I see the time diff between the
last packet sent to AP1 and the first sent to AP2.

I get a time diff of ~200ms.

>> Was the 80211r feature tested with mac80211 drivers?
> Yes.

Were you able to roam under 50ms?

> --
> Jouni Malinen                                            PGP id EFC895FA
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