[LEDE-DEV] TDW8970 Slow Wireless Performance when using VDSL2

[José Vázquez]

2016-11-06 11:47 GMT+01:00, Kevin Darbyshire-Bryant
<kevin at darbyshire-bryant.me.uk>:
>
>
> On 06/11/16 10:12, Xander Shelley wrote:
>> Hi there,
>>
>> I've installed LEDE Nov5 snapshot onto my TP-Link TD-W8970 router to use
>> with a UK fibre ISP (Plus.net)
>>
>> Out of the box most things work great.
>>
>> If I connect via Ethernet to the router from my xubuntu T410 laptop, and
>> run a speed test using (speedtest.net) I get close to line speed (31Mb/s
>> Line Speed, measured speed 29MB/s) which is great.
>
> VDSL2 overheads would account for the drop there.
>
>>
>> However, when I switch over to using wifi, this measured speed drops to
>> 12-16MB/s....
>>
>> Looking at the LuCI interface it shows that my laptop is connected
>> around 113MB/s which  is as expected.
>>
>> Am I doing anything incorrectly/missed a step in my setup?
>
> I can't offer any magic bullet.  Wifi is notoriously variable in terms
> of bandwidth and I have to say my 2.4Ghz is slower (similar to your
> measurement) than 5Ghz even though rates would suggest plenty of spare
> capacity.
>
> It's worth proving the router isn't running out of CPU though...a top
> during wired/wireless tests would be helpful.
>
> Kevin
>
Maybe I'm wrong but seems that in the case of lantiq mac80211 is
compiled with mips16 enabled, isn't it?
If this is true it could be the reason for the low speed you are experiencing.

https://git.lede-project.org/?p=source.git;a=blob;f=package/kernel/lantiq/ltq-vdsl/Makefile#l20