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Fix for wifi instability caused by multiple CWMP value change events

Danthelan — Sat, 23 Jan 2021 14:58:04 GMT

I have the BT Home Hub 2 with 5 Complete WiFi discs (the black ones) running the usual mix of computers, tablets, phone and airplay devices together with 9 wifi cameras and its NVR.

The system has been running 99.9% perfectly since the beginning of the year. On the 30th Dec last year I have a couple of these messages in the Technical Log of the Advanced Settings.

CWMP: Session start now, server: https://pbthdm.x.x.x, Event code: 4 VALUE CHANGE

These are BT logins and should not be any concern. On the 8th of January I had three more. Again no cause for concern, just BT getting into the hub to "do stuff". No drop outs or anything.

On 18th January from 10am to 1pm I had fourteen (14!) of these messages and my internal WiFi collapsed. Cameras where inaccessible, airplay printer wouldn't work, I got kicked from a work call over the next couple of days. Looking at the devices from the Smart Hub 2 Manager they were all connected with excellent signal strength (-45dBm or better), the discs were all connected correctly with good signal (-70dBm or better), but the Link Rate provided by the BT App showed 1Mbps for the devices in question.

The poor links jumped around various cameras and devices in a random fashion. I called BT and an engineer suggested a factory reset - which we did but that did not resolve the issue. The whole internal network is unreliable and inconsistent. Most of the traffic is internal (to prove this to myself I used the access controls in the app to shut off internet access to cameras and airplay devices).

Just had a BT engineer visit and he agreed that the CWMP value changes of the 18th correlated with the device issues. It looks to me as if the Hub is throttling or otherwise trying to manage the devices. Something that didn't happen before the 18th and these messages.

Does anyone know how to completely factory reset a Hub or why these config changes stick beyond a factory reset?

Re: Fix for wifi instability caused by multiple CWMP value change events

Keith_Beddoe — Sat, 23 Jan 2021 15:05:54 GMT

@Danthelan

The last firmware update changed the wireless mode to mode 2, for some reason.

Check it, and if its on mode 2, change it back to mode 1.

This has been reported before on this forum, and may be the cause of your problem.

Re: Fix for wifi instability caused by multiple CWMP value change events

imjolly — Sat, 23 Jan 2021 15:09:41 GMT

to factory reset presss the recessed button on back and hold for 20/30 secs until lights flash when reboots remember to turn off smart setup in hub manager

Re: Fix for wifi instability caused by multiple CWMP value change events

Danthelan — Sat, 23 Jan 2021 15:19:02 GMT

Thanks for the tip. I checked and it's still on Mode 1 - the firmware was updated on 30th Dec (v0.24.04.11017-BT)

Re: Fix for wifi instability caused by multiple CWMP value change events

Danthelan — Sat, 23 Jan 2021 15:21:57 GMT

The BT engineer and I did this reset a few days ago. I reset the SSID back to what I had before, which shows it was a factory reset rather than just cycling it, but the instability still occurs. Is there a "factory reset plus wipe out all the CWMP changes" procedure?

Re: Fix for wifi instability caused by multiple CWMP value change events

imjolly — Sat, 23 Jan 2021 15:25:33 GMT

you cannot revert back to old firmware after an update

have you tried changing the wifi channels from auto to specific channels I would use a wifi analyser app on smartphone which will show surrounding networks and also channels in use then select a free or less congested channel

Re: Fix for wifi instability caused by multiple CWMP value change events

Keith_Beddoe — Sat, 23 Jan 2021 15:27:37 GMT

The value change would be saved as part of the new firmware, and cannot be undone.

Re: Fix for wifi instability caused by multiple CWMP value change events

Danthelan — Sat, 23 Jan 2021 17:16:46 GMT

@imjolly The firmware that was loaded on the 30th Dec is good, I don't need to roll that back. The system was working for most of January. in the original post I explain it was only after the CWMP events that the system became unstable. The firmware version remains unchanged.

Yes, I have used NetSpot to map the environment and settled on channels without interference. I did another survey a couple of days ago and the chosen channels are still good. Out of interest, the problem with the hub showing a device as connected but not having it any bandwidth has affected both 2.4 and 5Ghz.

Re: Fix for wifi instability caused by multiple CWMP value change events

Danthelan — Sat, 23 Jan 2021 17:17:38 GMT

@Keith_Beddoe So the solution is a replacement Hub from BT then I guess.

Re: Fix for wifi instability caused by multiple CWMP value change events

Keith_Beddoe — Sat, 23 Jan 2021 17:21:38 GMT

@Danthelan wrote:

@Keith_Beddoe So the solution is a replacement Hub from BT then I guess.

Quite possibly, as the firmware may be corrupted.

Re: Fix for wifi instability caused by multiple CWMP value change events

Danthelan — Sat, 23 Jan 2021 18:05:03 GMT

I just checked the Technical Log and alongside the 14 CWMP value changes on the 18th there were 35(!!!!!!) CWMP value changes on the 19th Jan.

Has anyone else had this level of interference on these days on a Hub 2?