The engineer visited on Saturday morning.
He firstly ran a TDR test from the cabinet which on arrival at my home said was all clear.
He did say he had cleanedu up slightly corroded connections in the cabinet that may have made a slight difference.
He also replaced the filtered part of the faceplate & when carrying out various other tests from his Exfo, noticed that the last 5mm or so of the incoming drop wire snapped off one of the legs (insulation test failed).
He stripped back the insulation & all the other tests were then O.K.
The Leg Balance Test came back with a result of around 12 for each leg, which is apparently perfect.
A final TDR test on completion of his work was apparently O.K. too.
I don't have a photo of the trace, but it looked roughly like this:-
The cabinet is shown by the large peak & the "hump" that I queried is apparently typical & nothing to be concerned about.
The engineer also said that it looks like the line is all copper, otherwise he would have seen other small peaks/troughs in the trace.
On requesting a sync recalc/DLM reset, the guy at the fibre centre (I think the engineer called it OMC or some similar abbreviation) mentioned they are aware of a long history of instability & frequent re-syncs & low(ish) speeds for my connection.
He & the engineer both agreed that I should really have a stable & slightly higher speed connection over the 834m line length as reported by the Exfo.
The OMC guy believes there is still some other "underlying" issue regarding my connection.
I wonder if the "hump" in the TDR trace is anything of a pointer.
I would say the "hump" is roughly one third of the distance from my house, going toward the cabinet.
Do you have any thoughts on this?
As the engineer first sorted the slight corrosion before running his first TDR test, we don't have "before & after" TDR traces, but the work carried out on Saturday appears to have cured the dropping SNRM when the phone is in use issue.
Now, SNRM only drops by around 0.1dB & 0.2dB when the phone is in use.
SNRM, fluctuating output power levels, attainable rates, error counts etc. all now appear quite stable.
However, from my modem stats, attenuation for each band is still slightly higher than it was for a few months previously.
from the Exfo:-
Actual Line Rate 6 24Max Rate 6 33
Capacity 100% 75%Noise Margin 6 9
Output 6.3 11.2Loop Attenuation 7.9 31.6
Signal Attenuation 11 31.4
DS attenuation looks surprisingly high & US attenuation looks surprisingly low when compared against previous JDSU stats.
Is that a known phenomenon with the 2 different testers?
My sync speed is currently 32209 k, whereas a fairly recent DLM reset (a couple of weeks prior to the SNRM issue) achieved a sync speed of 35322 k.