Hi
I've got FTTC broadband with BT. Download sync speed is around 42 to 48Mb. SNR margin usually around 5db, but this fluctuates quickly (e.g. it could be 5 one second and then 5.8 just a second or two later).
An extension lead is wired into the original master socket (which itself is disconnected) and the lead runs around the edge of the living room into a new BT master socket on the wall, which the Billion router's connected to. (This setup was done by the previous homeowner!)
Since I moved in in 2018, I've had the occasional dropout but nothing too bad, with syncs often lasting for several weeks. At the end of November, after being synced for a month, the router resynced with a lower SNR margin (around 2 or 3db) and the sync speed was much higher than usual (52Mb). I assume this was DLM intervention.
This caused a lot of errored seconds and I assume the DLM intervened again as it resynced again at a higher SNR margin, lower speed and then the errors went. Since then there have been random resyncs once a week or so at random times of day. I have a Raspberry Pi and set it up to record the SNR margin each second.
I've found that every few days the SNR margin drops to below 2 for about 5-10 seconds but it doesn't cause a resync. Last night though it twice dropped down like this and went so low it caused two resyncs (I went into the router stats and it registered -4 db just before dropping). I listened to the phone line when the SNR margin dropped and there was no noise at all.
I've checked against when my heating kicks in and I don't think there's a link. I can't think of anything else that could cause it.
However, I've noticed the router can be sensitive to what I assume is electrical noise. For example I once switched a fan on upstairs and it caused a resync. I tried turning the fan off/on again and it caused another resync so it was definitely the fan. I rebooted the router, tried the fan again and it was then fine.
The router's near my Raspberry Pi and a couple of other power adapters for the TV etc., which I know isn't ideal, and neither is the odd master socket setup. However I've had it like this for years and it's not been a problem.
Is it possible that something like the fridge or freezer (in the next room) has started to cause interference on the mains? Or perhaps a nearby power adapter has started doing it?
I'm considering buying a Tacima mains conditioner to see if this will help, but I'd appreciate any advice as I'd like to ensure this problem doesn't worsen.
Attached are the current router stats since last night's resync.
Thanks.