Hi All,
Is there a parameter in hostapd.conf or elsewhere to enable/disable MPDU
and MSDU aggregation? Please reply as this is very urgent.
Thanks in advance,
Sourav
On 12/09/14 18:00, Sourav wrote:
On 12/09/14 17:46, Helmut Schaa wrote:
On Fri, Sep 12, 2014 at 4:11 AM, Sourav
<sourav.chakraborty@xxxxxxxxxxxxxxxxxxx> wrote:
On 11/09/14 00:14, Helmut Schaa wrote:
On Wed, Sep 10, 2014 at 10:42 AM, Arend van Spriel
<arend@xxxxxxxxxxxx>
wrote:
On 09/10/14 03:26, Sourav wrote:
We are using Ralink chip Rt3072L (using rt2800usb drivers
rt2800usb.c),
The Ralink USB hardware is quite bad in reporting TX status and as
such minstrel_ht cannot do proper rate selection.
If you watch the rc stats at
/sys/kernel/debug/ieee80211/phy0/netdev\:wlan0-0/stations/xx:xx:xx:xx:xx:xx/rc_stats
you might see a lot of rate selection "hopping".
Regards.
Helmut
please take a look at the attachments.... the first one shows the
rc_stats
and iperf stats side by side on the router(iperf is running in
client mode
in the router).....the second attachment is from a laptop which is
running
iperf in server mode.
I don't see a lot of rate "hopping" in the rc_stats file, (T,t and
P) rates
are pretty much stable.... yet there is a big difference between
those rates
and the throughput using iperf......
Indeed, rc_stats looks acceptable.
when you say "Ralink USB hardware is quite bad in reporting TX
status", do
you mean that the HW reports less tx rate to minstrel_ht and so its
rate
calculation is screwed up?
The HW sometimes does not report the status of transmitted frames
correctly.
The TX status register is a FIFO of 16 (or similar) elements and if
the driver is
not reading it "fast enough" the FIFO will overflow :( at least that
was the point
when I was looking at the ralink hardware last time. Not sure if
something
changed recently.
How did you detect this? I can see no error messages in
syslog....hence I am thinking that the HW is processing packets
properly....though I may be wrong here.
Can you please let me know the section of code inside
Rc_80211_minstrel_ht.c
(or somewhere else) which deals with getting the tx rate from ralink
HW?
There is no special code in minstrel(_ht) in regard to rt2x00.
Are you able able to get some statistics on the receiver side (your
windows machine)
regarding TX rates and AMPDU lengths?
the 2nd attachment had logs from the windows machine.....it is also
showing similar rates as on the router
Helmut
--
Warm Regards,
Sourav
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