Hiya guys and gals,
To summarise what this post will be about, I have been having some large fluctuations (in the form of spikes) on the upstream SNRM along with up to a couple of disconnections a day for the past month especially. Not only are there disconnects, but there can be huge amount of errors and upstream sync speed can spike downwards massively (sometimes spiking below 30 Mbps).
Looking back a few months and beyond, there have been a few occurrences here and there where the SNRM margin on the upstream was a bit impacted. So, while it was not too unusual to see occasionally, it could be even weeks between the occurrences and the impact was not noticed as disconnects never really happened.
What has changed now is that it is happening almost every day recently, especially since around the 8th February. I understand we have had some wet, windy weather. But it looks like that may not be the exact cause since the weather does not seem to always overlap in a meaningful way and may be the contrary – some dry days may have the issue, while wet days may not (correlation ≠ causation, anyway). However, I am not ruling it out completely since during heavy rain one night I had experienced popping on the phone line while in the test socket (though I have been unable to replicate it since).
I have reported it to Zen, but the tests keep coming back clear and they cannot see the fluctuations like I can. However, they did note that there had been a lot of errors but do not want to raise the fault to Openreach due to the risk of no fault being found. I understand their position since knowing my luck they will come out and it will not be occurring at the time, but I think I have finally hit the point of it looking like a problem somewhere since the DLM has finally set the target SNRM to 10 dB and it is slowly eating into my upstream (~47 Mbps sync. and attainable, down from ~50 Mbps sync. and ~64 Mbps attainable – yes, it is hardly anything in terms of actual sync., but signifies the point of impact).
I have done a few things, such as switching the filters and cables – no change. The phone is never plugged in so it cannot be that. The drop cable is new since January 2018, and the socket received some attention (upgraded the faceplate) when G.fast was provisioned last year and checked again when a fault was raised a little while after. I cannot really switch the modem if I want to be able to log since the only spare modem I have is the MT992 (though if the DLM raises the SNRM more I could use it to see if the sync. improves via Zen support or their panel once the modem is switched).
I have attached a few images as examples to what I am seeing my end - just attached 29th February as an example. There have been worse and better days, just wanted to pick a more recent one.
Any suggestions and opinions?
TIA.