I am struggling to understand a problem with a SNR (and hence the connection sync. rate) on the upstream signal which is very variable. Does this imply that the source of the noise/interference is local? Or is it just indicative of a problem at low frequencies that could be anywhere on the line? The former hypothesis was put to me by the Demon tech. support rep. I was talking to about the problem (this issue is not a Plusnet one but I know this forum is a good source of expertise).
It is a problem at low frequencies somewhere on the line I had exactly that with uncapped upstream on my line so went back to capped I also get occasional noise on the phone line and things can go badly wrong in very heavy rain - masses of uncorrected downstream errors - several BT visits didn't sort it and as the feed to me house comes from a shared pole (with electrical supply to another property) getting it investigated properly is impossible so I live with it