WIFI Congestion?–Help Requested?

Update: See bottom

I have a problem – and I’m going to shamelessly use this blog to see if someone can help.

In the midst of my home control nirvana – I’m having some WIFI issues that I simply don’t understand.

So -  my setup:  Broadband coming in is maybe 6Mb in each direction so no issues of lack of speed.  It comes into a Draytek (PPOE) router from a small window mounted dish to a large aerial in the middle of the village. I have no problem streaming TV or downloading big programs etc.

Indeed I have very few problems with hardwired use – our PCs always connect to the web. I’ve had my little wifi ESP boards talking to a Raspberry Pi for months without issue.. and then a couple of weeks ago it started…

The units would log in but not stay logged in, or be unable to login. I thought it might be my little WIFI control units – but then my wife started griping here phone would not log into the network. The mobile phones suggest this is not an issue with my little WIFI boards.   Sure enough – try to log in – the phone would say “connecting” then just go back to “saved” .  After a while it would connect for no good reason.

I switched the WIFI off for a couple of hours and back on. All was well for maybe 30 hours – and then slowly but surely my little control units would have trouble logging into the WIFI – and so would our mobile phones.  Strangely, though our PCS which are hardwired would have no apparent issues, I’d find it might take seconds to connect to the router with the web interface, something that should be virtually instant. WHY? The router is on a wire as is the computer. What can be so jamming up the network?

So – I reduced the router to factory settings. I altered the DHCP to start at and did some IP-MAC fixing for things like the PI (well, two or three of them) and my PC. This was to ensure that no devices with fixed IPs were in the same range with possible overlap with devices working on DHCP. We’re taking maybe 20 devices all in – some controllers, a couple of computers, 2 phones, 2 tablets, 2 Raspberry Pis… and some ESP8266 WIFI units.

All worked well, my devices operated flawlessly as did the phones and the TV for DAYS on end. Yesterday a couple of times I heard devices logging in to the Pi (I have speech warnings). Might be an issue, might be not.

But this morning, whatever is wrong is back full steam, devices logging in every few minutes and generally not taking any notice of remote instructions – or taking ages to respond.  It is as if something is absolutely hogging the radio network.

And yet… I put checks in to see how many messages were  being passed back and forth between my PI and the devices… one a second if that – no big deal. I’ve looked at bandwidth use in the router – nothing stands out . BUT SOMETHING is gumming up the works.  I have 3 routers acting as access points and yes I’ve spread channels so no overlaps.

I’m missing something here, I have no way to see what it is that is actually going wrong here.  If anyone considers themselves a whiz at wireless networks – feel free to get in touch – pete@scargill.org – I could do with some fresh thinking.

Update 28/10 – A couple of days with almost no problems – tonight back with a vengeance – WIFI feels “clogged” – attempts to get Wireshark invariably gave me an incomplete download on my otherwise very fast laptop. Went to the (wired) PC and no problem.

Here’s a heatmap of the place with very rough positions of kit.. only the two WIFI access points (actually identical position as both on the Draytek) are mine – others are WAY further away than they look and so unlikely to cause problems.  All but one is nearly a street away.



So after having difficulty loading Wireshark, I downloaded it on my WIRED machine and ran on the laptop in the main room – I’ve no idea how to run Wireshark but I’m pretty sure that screen was showing problems – failures, some stuff in red, retries… After saving the file from Wireshark I turned off the external WIFI coming in – and turned the Draytek off. I left them both off for maybe 10 minutes. I turned them back on – hardly any units logged in and would not communicate (but one did as the Pi replayed the login message that comes from the unit). So any ideas of overheating went out the window (it’s cooler here today anyway than normal).

At this point, I’m sitting with a perfectly working wired machine, a laptop that seems ok and ESP units that are failing to get through – and resetting – after many hours of operating perfectly.  The laptop is seeing my two access points and next doors, intermittently – they are actually disappearing and re-appearing. Next I started to turn off all the ESPs, no difference, the mobile phones – no difference. My wife who by now was in bed reading said that the WIFI said it was disabled.  I even disconnected the Raspberry Pis from the network – no difference, our neighbour’s weak signal and our two strong signals were turning on and off, on and off on my Windows 10 tablet.  I turned off the dish and the router – this left the neighbour’s signal – still turning on and off about once a second. Turned the router back on – turned the phone on and turned on WIFI Analyser on the phone – I could watch the two WIFI signals come on full strength – and turn off – once every few seconds (I suspect even though it has a 1 second refresh it’s response is slower). I turned the entire Pergola off (PWM solar powered lights – actually disconnected the battery – no difference.

I need sleep.