[ale] WIFI mystery speed problems

[Alex Carver]

Run a site survey (using a laptop) when the problem occurs to see if
there's another AP nearby using the same frequency.  You may just need
to change channels if the area has become congested.


On 2016-02-18 09:31, 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.
> 
> NOTE: tests via 10baseT wired connections are consistently at 29+Mb/s;
> wifi is 26-29 when good, when bad between 0.9 and 4Mb/s. When the wifi
> is bad, the wired results remain good: so this is a wifi problem - can't
> blame it on comcast :)
> 
> The router is an Asus RT-N16 running Tomato/Shibby.   Google shows
> others getting much better throughput with this hardware/firmware combo
> (70+Mb/s) so I don't think the router or firmware is likely to blame
> (unless I have flakey hardware ?)
> 
> I've been logging through a speedtest-cli cronjob for the past week and
> 6 days out of 7, I see this behavior (performance degrades starting
> between 9pm and 2am, continues even after the router auto-reboots at 5am
> and then eventually returns to normal by about 9am.
> 
> Things I've tried:
> 
>  * I cannot identify any equipment in the house that might be causing
>    radio interference - and certainly nothing that is on a periodic
>    schedule that matches these overnight outages.
>  * Reboot the router - has no effect.
>  * Checked that this is not client specific. When the performance
>    degrades, I measure the same throughput on all clients (laptops,
>    phones).
>  * There is no load on the wifi during these outages (no long running
>    file transfers, backup rsync's or streaming).
>  * I disabled bandwidth and ip monitoring (which I understand to be a
>    known bottleneck in Tomato).  This improved the "normal" throughput
>    a bit, but has not solved the periodic slow "outages".
>  * I moved the router to a variety of locations (on theory that there
>    may be some unusual interference on one location or the other)
> 
> 
> I'm looking for ideas of more things to try before I reflash the
> original firmware and see if Asus's software works better... (followed
> by trash the asus and buy a new router :( ).
> 
> Help! (and thanks,)
> Steve