[ale] WIFI mystery speed problems

[Alex Carver]

On 2016-02-23 05:37, Steve Tynor wrote:
> An update and preliminary declaration of victory.
> 
> In one of many random config changes (mostly trying to change channels),
> I changed the "channel width" from 40 Mhz to 20 Mhz. Since making that
> change, the network has been rock solid - no silly slowdowns.   As I
> understand it, the 40Mhz setting was supposed to improve bandwidth but I
> never measured any improvement -- and in fact, turning it back down to
> 20 Mhz seems to have solved my periodic slowdown problem.
> 
> Thanks again for all the help and advice,
> Steve
> 
> On 2/18/16 12:31 PM, Steve Tynor wrote:
>> I'm looking for some brainstoming ideas to explain why my home wifi
>> router's performance is suddenly acting so strange: periodically
>> (about once a day), performance (as tested by speedtest.net)
>> drastically decreases from ~30Mb/s to ~4Mb/s.
>>
>> When this happens, there's nothing I can do to make it better.
>> Rebooting the router has no effect.  The speed comes back when its
>> good and ready - not before.  These "outages" usually last about 12
>> hours.  Performance is bad from all clients - macbook, ubuntu laptop,
>> phones - so this seems to be router specific - not due to client config.
> ...


That probably means the front-end radio couldn't handle the bandwidth.
I'm sure the power envelope was not ideal (significant roll-off, spurs,
etc.) so narrowing your bandwidth would put you in the radio's sweet
spot of operation.

The radio in consumer routers (and a few commercial APs) is built for
profit not performance.