Re: low TCP throughput with 80MHz channel width

[Ben Greear <greearb@candelatech.com>]

On 04/22/2016 09:44 AM, Iñaki Pascual wrote:
> Thanks for your help Ben.
>
> I think we will go for kernel 4.4 and the latest firmware relase.
>
> Regarding the firmware, should we try the CT-10.2 or it is not stable enough?

My 10.2 has not had much testing, and in recent testing, it does not perform as well as my 10.1
firmware.  But, you could give it a try to see how well it works....

4.4 seems to be working this morning, but was broken yesterday: It is in fairly heavy development, so possibly you will
hit regressions there.  Let me know if you do.  It also has a bunch of upstream testing ath10k patches, and I saw other reports
that TCP throughput is less with them applied, though possibly this is only true if you are using codel tx queueing.

Thanks,
Ben

>
> Bests,
>
> Iñaki
>
>
>
> On 22/04/16 18:16, Ben Greear wrote:
>> On 04/22/2016 09:11 AM, Iñaki Pascual wrote:
>>> We are using kernel 4.2 with CandelaTech firmware 10.1.467-ct-com-full-014-96d543
>>
>> Maybe try rls 15 or beta-16 CT 10.1 firmware?
>>
>> And, we found too much instability in 4.2 kernel.  We suggest 4.0 or 4.4,
>> though I am not aware of any throughput related bugs aside from the CUBIC
>> congestion control issue.
>>
>> You might also try our 3.17 kernel since CUBIC worked in that kernel...
>>
>> Thanks,
>> Ben
>>
>>
>>>
>>> monet@sc227:~$ ethtool -i wlan2
>>> driver: ath10k_pci
>>> version: 4.2.0+
>>> firmware-version: 10.1.467-ct-com-full-014-96d543
>>> bus-info: 0000:0b:00.0
>>> supports-statistics: yes
>>> supports-test: no
>>> supports-eeprom-access: no
>>> supports-register-dump: no
>>> supports-priv-flags: no
>>>
>>> Thanks,
>>>
>>> Iñaki
>>>
>>> On 22/04/16 18:06, Ben Greear wrote:
>>>> On 04/22/2016 09:02 AM, Iñaki Pascual wrote:
>>>>
>>>>> Thanks for the tip Ben. We have moved to 'reno' and tried several window sizes but we are still on max. 35 Mbps which is too low.
>>>>>
>>>>
>>>> What firmware and kernel are you using?
>>>>
>>>> Thanks,
>>>> Ben
>>>>
>>>>> Bests,
>>>>>
>>>>> Iñaki
>>>>>
>>>>> On 22/04/16 17:40, Ben Greear wrote:
>>>>>> Use 'reno' instead of cubic TCP congestion control, cubic is broken with ath10k.
>>>>>>
>>>>>> Thanks,
>>>>>> Ben
>>>>>>
>>>>>> On 04/22/2016 08:32 AM, Iñaki Pascual wrote:
>>>>>>> Hi everyone,
>>>>>>>
>>>>>>> we have configured two boxes with 802.11ac NICs to work in channel 48 (5240 MHz), ad-hoc mode, 80MHz channel width.
>>>>>>> For UDP traffic we get 300 Mbps bandwith but for TCP we are around 30 Mbps.
>>>>>>>
>>>>>>> We have tried other channels with similar results.
>>>>>>> Throughput for 20 and 40 MHz channel width are ok (20MHz: TCP 21Mbps, UDP 27Mbps, 40MHz: TCP 82Mbps, UDP 144Mbps).
>>>>>>>
>>>>>>> Testing with iperf we have also tried different congestion windows with no or low improvements.
>>>>>>>
>>>>>>> Below are config details and the sequence of commands we are using to configure the interface.
>>>>>>>
>>>>>>> Any ideas on what we may be doing wrong?
>>>>>>>
>>>>>>> Bests,
>>>>>>>
>>>>>>> Iñaki
>>>>>>>
>>>>>>> iw outputs:
>>>>>>>
>>>>>>> root@sc227:/home/monet# iw wlan2 info
>>>>>>> Interface wlan2
>>>>>>>      ifindex 6
>>>>>>>      wdev 0x200000001
>>>>>>>      addr 04:f0:21:18:26:a2
>>>>>>>      ssid SC226SC227
>>>>>>>      type IBSS
>>>>>>>      wiphy 2
>>>>>>>      channel 48 (5240 MHz), width: 80 MHz, center1: 5210 MHz
>>>>>>>
>>>>>>> root@sc227:/home/monet# iw wlan2 station dump
>>>>>>> Station 04:f0:21:18:26:a8 (on wlan2)
>>>>>>>      inactive time:    86 ms
>>>>>>>      rx bytes:    467732521
>>>>>>>      rx packets:    364249
>>>>>>>      tx bytes:    1394558
>>>>>>>      tx packets:    16200
>>>>>>>      tx retries:    0
>>>>>>>      tx failed:    0
>>>>>>>      signal:      -51 dBm
>>>>>>>      signal avg:    -51 dBm
>>>>>>>      tx bitrate:    351.0 MBit/s VHT-MCS 4 80MHz VHT-NSS 2
>>>>>>>      rx bitrate:    526.5 MBit/s VHT-MCS 4 80MHz VHT-NSS 3
>>>>>>>      authorized:    yes
>>>>>>>      authenticated:    yes
>>>>>>>      preamble:    long
>>>>>>>      WMM/WME:    yes
>>>>>>>      MFP:        no
>>>>>>>      TDLS peer:    no
>>>>>>>      connected time:    3169 seconds
>>>>>>>
>>>>>>>
>>>>>>> config commands:
>>>>>>>
>>>>>>> ifconfig wlan2 down
>>>>>>> iw wlan2 set type ibss
>>>>>>> ifconfig wlan2 up
>>>>>>> ifconfig wlan2 10.2.1.7 netmask 255.255.255.0
>>>>>>> iw wlan2 ibss join SC226SC227 5240 80MHz
>>>>>>>
>>>>>>> iperf:
>>>>>>> root@sc227:/home/monet# iperf -c 10.2.1.6
>>>>>>> ------------------------------------------------------------
>>>>>>> Client connecting to 10.2.1.6, TCP port 5001
>>>>>>> TCP window size: 85.0 KByte (default)
>>>>>>> ------------------------------------------------------------
>>>>>>> [  3] local 10.2.1.7 port 48548 connected with 10.2.1.6 port 5001
>>>>>>> [ ID] Interval       Transfer     Bandwidth
>>>>>>> [  3]  0.0-10.0 sec  33.1 MBytes  27.7 Mbits/sec
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> ath10k mailing list
>>>>>>> ath10k@lists.infradead.org
>>>>>>> http://lists.infradead.org/mailman/listinfo/ath10k
>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>
>>
>>
>


-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com


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