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* [ath9k-devel] Hostapd+WMM causes packet loss
@ 2013-08-25 15:57 Rasto Sramek
  2013-08-25 17:56 ` Adrian Chadd
                   ` (2 more replies)
  0 siblings, 3 replies; 14+ messages in thread
From: Rasto Sramek @ 2013-08-25 15:57 UTC (permalink / raw)
  To: ath9k-devel

Hello, 

I was redirected here from hostapd mailinglist. I am trying to
run a 802.11n 5GHz AP from a tl-wdn4800 pci-e 3x3 adapter which seems to
contain a AR9380 chipset.

With disabled wmm (wmm_enabled=0), I get reliable connection at 54 Mb/s,
1-4ms ping with no apparent packet loss, and around 17 Mb/sec actual
transfer rate:
[  3]  0.0- 1.0 sec  2.12 MBytes  17.8 Mbits/sec
[  3]  1.0- 2.0 sec  2.00 MBytes  16.8 Mbits/sec
[  3]  2.0- 3.0 sec  2.00 MBytes  16.8 Mbits/sec
[  3]  3.0- 4.0 sec  2.00 MBytes  16.8 Mbits/sec
[  3]  4.0- 5.0 sec  2.12 MBytes  17.8 Mbits/sec
[  3]  5.0- 6.0 sec  2.00 MBytes  16.8 Mbits/sec
[  3]  6.0- 7.0 sec  2.00 MBytes  16.8 Mbits/sec
[  3]  7.0- 8.0 sec  2.00 MBytes  16.8 Mbits/sec
[  3]  8.0- 9.0 sec  2.00 MBytes  16.8 Mbits/sec
[  3]  9.0-10.0 sec  2.12 MBytes  17.8 Mbits/sec


When I enable wmm, I get faster connection (up to 270 Mbit/s)
with significant packet loss which seems to come every few
seconds for a second or more:

[  3]  0.0- 1.0 sec  9.12 MBytes  76.5 Mbits/sec
[  3]  1.0- 2.0 sec  4.75 MBytes  39.8 Mbits/sec
[  3]  2.0- 3.0 sec  3.38 MBytes  28.3 Mbits/sec
[  3]  3.0- 4.0 sec  3.25 MBytes  27.3 Mbits/sec
[  3]  4.0- 5.0 sec  6.25 MBytes  52.4 Mbits/sec
[  3]  5.0- 6.0 sec  3.50 MBytes  29.4 Mbits/sec
[  3]  6.0- 7.0 sec  3.12 MBytes  26.2 Mbits/sec
[  3]  7.0- 8.0 sec  6.38 MBytes  53.5 Mbits/sec
[  3]  8.0- 9.0 sec  0.00 Bytes  0.00 bits/sec
[  3]  9.0-10.0 sec  6.62 MBytes  55.6 Mbits/sec
[  3] 10.0-11.0 sec  0.00 Bytes  0.00 bits/sec
[  3] 11.0-12.0 sec  1.12 MBytes  9.44 Mbits/sec
[  3] 12.0-13.0 sec  5.25 MBytes  44.0 Mbits/sec
[  3] 13.0-14.0 sec  6.38 MBytes  53.5 Mbits/sec
[  3] 14.0-15.0 sec  3.25 MBytes  27.3 Mbits/sec
[  3] 15.0-16.0 sec  3.75 MBytes  31.5 Mbits/sec
[  3] 16.0-17.0 sec  0.00 Bytes  0.00 bits/sec
[  3] 17.0-18.0 sec  0.00 Bytes  0.00 bits/sec
[  3] 18.0-19.0 sec  6.88 MBytes  57.7 Mbits/sec
[  3] 19.0-20.0 sec  0.00 Bytes  0.00 bits/sec
[  3] 20.0-21.0 sec  0.00 Bytes  0.00 bits/sec
[  3]  0.0-21.4 sec  73.1 MBytes  28.6 Mbits/sec

This doesn't seem to be just QoS load prioritizing,
since ping in a no-load situation has similar issues:

64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=6.14 ms
64 bytes from 10.0.0.1: icmp_seq=2 ttl=64 time=2.85 ms
64 bytes from 10.0.0.1: icmp_seq=3 ttl=64 time=5.03 ms
64 bytes from 10.0.0.1: icmp_seq=4 ttl=64 time=3.79 ms
64 bytes from 10.0.0.1: icmp_seq=5 ttl=64 time=3.66 ms
64 bytes from 10.0.0.1: icmp_seq=6 ttl=64 time=2.50 ms
64 bytes from 10.0.0.1: icmp_seq=13 ttl=64 time=2.54 ms
64 bytes from 10.0.0.1: icmp_seq=17 ttl=64 time=2.96 ms
64 bytes from 10.0.0.1: icmp_seq=18 ttl=64 time=7.66 ms
64 bytes from 10.0.0.1: icmp_seq=19 ttl=64 time=3.22 ms

Both clients, running Intel Ultimate-N 6300 3x3 cards,
are affected. The wireless spectrum seems to be more or less clear
containing only 2 other weak 5GHz APs, both on Channel 44
compared to my 48.

Is this a known issue? I couldn't find any mention of it.
Can someone point me at what I should try? I tried
using a different channel but I did not see any change
in behavior.

Thanks!

Rasto

====================================================
Versions/Configuration:

Client:
Debian, vanilla 3.9.8 kernel, wpa_supplicant 1.0-3+b2
Server:
Debian, debian 3.10-2-amd64 kernel, hostapd 1.0-3+b2

lspci -v:
01:00.0 Network controller: Qualcomm Atheros AR93xx Wireless Network
Adapter (rev 01)
        Subsystem: Qualcomm Atheros Device 3112
        Physical Slot: 0
        Flags: bus master, fast devsel, latency 0, IRQ 16
        Memory at fe9e0000 (64-bit, non-prefetchable) [size=128K]
        Expansion ROM at fe9d0000 [disabled] [size=64K]
        Capabilities: [40] Power Management version 3
        Capabilities: [50] MSI: Enable- Count=1/4 Maskable+ 64bit+
        Capabilities: [70] Express Endpoint, MSI 00
        Capabilities: [100] Advanced Error Reporting
        Capabilities: [140] Virtual Channel
        Capabilities: [300] Device Serial Number 00-00-00-00-00-00-00-00
        Kernel driver in use: ath9k

parts of hostapd.conf that seem relevant:

interface=wlan0
bridge=br0
driver=nl80211
hw_mode=a
channel=48
rts_threshold=2347
fragm_threshold=2346

wmm_enabled=1
wmm_ac_bk_cwmin=4
wmm_ac_bk_cwmax=10
wmm_ac_bk_aifs=7
wmm_ac_bk_txop_limit=0
wmm_ac_bk_acm=0
wmm_ac_be_aifs=3
wmm_ac_be_cwmin=4
wmm_ac_be_cwmax=10
wmm_ac_be_txop_limit=0
wmm_ac_be_acm=0
wmm_ac_vi_aifs=2
wmm_ac_vi_cwmin=3
wmm_ac_vi_cwmax=4
wmm_ac_vi_txop_limit=94
wmm_ac_vi_acm=0
wmm_ac_vo_aifs=2
wmm_ac_vo_cwmin=2
wmm_ac_vo_cwmax=3
wmm_ac_vo_txop_limit=47
wmm_ac_vo_acm=0
ieee80211n=1
ht_capab=[HT40-][SHORT-GI-40]

wpa=2
wpa_key_mgmt=WPA-PSK WPA-EAP
wpa_pairwise=CCMP TKIP
rsn_pairwise=CCMP

^ permalink raw reply	[flat|nested] 14+ messages in thread
* [ath9k-devel] Hostapd+WMM causes packet loss
@ 2013-08-27  7:41 Rasto Sramek
  0 siblings, 0 replies; 14+ messages in thread
From: Rasto Sramek @ 2013-08-27  7:41 UTC (permalink / raw)
  To: ath9k-devel

On Mon, Aug 26, 2013 at 01:35:33PM +0530, Sujith Manoharan wrote:
> Rasto Sramek wrote:
> > I'm attaching the log from start to the problem. There is nothing
> > actually at the time of the problems apart from
> > 1377499227.634542: Add randomness: count=699 entropy=585 messages.
> > 
> > Earlier on it says it switched channels because secondary contains 
> > another BSS.
> > 
> > 1377499191.630232: nl80211: Set freq 5220 (ht_enabled=1
> > sec_channel_offset=1)
> > 1377499191.630352: Failed to update rate sets in kernel module
> 
> This is the only message that is a bit suspicious. Can you try with
> latest hostapd.git ? Also, make sure that background scan is not
> enabled
> on the clients.
> 
> Sujith

I compiled hostapd from git and the problem is subjectively worse,
typical iperf:
[  3]  0.0- 0.5 sec   128 KBytes  2.10 Mbits/sec
[  3]  0.5- 1.0 sec  0.00 Bytes  0.00 bits/sec
[  3]  1.0- 1.5 sec  1.00 MBytes  16.8 Mbits/sec
[  3]  1.5- 2.0 sec  2.62 MBytes  44.0 Mbits/sec
[  3]  2.0- 2.5 sec   384 KBytes  6.29 Mbits/sec
[  3]  2.5- 3.0 sec  0.00 Bytes  0.00 bits/sec
[  3]  3.0- 3.5 sec  0.00 Bytes  0.00 bits/sec
[  3]  3.5- 4.0 sec  0.00 Bytes  0.00 bits/sec

It did not seem immediately obvious how to disable background scans,
I will look into that.

Rasto

^ permalink raw reply	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2013-08-27  7:41 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-08-25 15:57 [ath9k-devel] Hostapd+WMM causes packet loss Rasto Sramek
2013-08-25 17:56 ` Adrian Chadd
2013-08-25 18:28   ` Rasto Sramek
2013-08-25 22:01     ` Mihai Moldovan
     [not found]       ` <20130825223317.GB15502@100acrewood.org>
2013-08-25 23:17         ` Mihai Moldovan
2013-08-26  6:13           ` Rasto Sramek
2013-08-26  3:29 ` Sujith Manoharan
2013-08-26  6:16   ` Rasto Sramek
2013-08-26  6:30     ` Sujith Manoharan
2013-08-26  6:57       ` Rasto Sramek
2013-08-26  8:05         ` Sujith Manoharan
2013-08-26 16:46 ` michael-dev
2013-08-27  7:38   ` Rasto Sramek
  -- strict thread matches above, loose matches on Subject: below --
2013-08-27  7:41 Rasto Sramek

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