Update 20/04/12:I am still awaiting Plusnet to contact me since reporting 5 re-syncs in a row, simply from using the phone on Monday 16th (4 from dialling out & 1 from receiving a call).
Therefore no engineer visit has been arranged & I am not aware of any work being carried out on my connection that did not require a home visit.
Would you believe it? Just look at a couple of graphs showing the latest 3 days connection:-
You can see on the R/H side that I was so confident with the stability that I rebooted the modem this morning to achieve a higher sync speed (now 31244 k).
The connection appears to have stabilised IMMEDIATELY after receiving the incoming call.
Hence my earlier query about ringing voltages creating temporary fixes.
I am also back on a 40Mb/10Mb max profile (by request) following the 80/20 trials.
I think the switch back is purely coincidental as the phone calls causing the re-syncs occured AFTER the switch back.
Compare the 3 day graphs shown above with these - from the latest 8 days.
The immediate difference since that incoming call can be clearly seen:-
Due to the scale/resolution of the graphs, the 5 re-syncs cannot be seen clearly, but I could separate the period around 07:00 to show them as evidence & my modem log has also recorded them.
The phone issue & general stability appear to have gradually improved since Monday.
I can now use the phone with hardly any drop in SNRM being seen.
Is it pure coincidence that the weather has been wetter & colder since Monday?
In a way I am slightly disappointed with this stability as I am sure it has only prolonged the inevitable return to instability & lower speeds.
If an engineer turned up right now, no doubt all his tests would return LTOK results.
I wonder if any return to instability will coincide with weather changes i.e. (hopefully) improving as we head toward summer?