My gut feel says that you should be getting better speeds for that distance, but the first question is... is that a realistic estimate for distance?
We can't tell directly (though an Openreach engineer can get an estimate off the JDSU). However, we can get a feel for distance based on the attenuation figures. They will be slightly different through copper & aluminium, and it can vary based on the diameter of each cable. However, it is the attenuation that affects the drop-off in speed more directly than the distance.
My current line is about 450 metres, and gets 40/10 with a max attainable of 90/26 according to the modem or 85/24 according to the JDSU.
For comparison, here are my line stats
, although they are generated with the Unix commands, so they look a little different, and have different axis values.
Your modem shows attenuation figures of 10dB for D1, 22.5dB for D2, and 33.8dB for D3.
My equivalent figures are 11.4dB for D1, 27.3dB for D2, and 41.4dB for D3. As attenuation is linear, it suggests that your line is 20% shorter than mine - so around 350 metres.
So - attenuation looks OK, and probably means you are on copper, without any obvious problem in that regard.
The next thing to look at is the noise. The SNRM values from the "pbParams" section show yours to be 8.6dB, 8.6dB and 8.4dB - where mine are all about 21dB. This is what you'd expect after the modem reports a much lower maximum attainable figure - that there is much less margin. However, your TX power levels are higher, suggesting that the signal level is a little higher at the cabinet, and with less attenuation, will be higher at the modem.
That suggests that the problem isn't the amount of signal - so must be noise.
The QLN (quiet line noise) graph demonstrates this. As I understand it, a value of around -140 dBm means a pretty quiet noise level. My line shows values of -130 to -140 in the ADSL range, and then -120 to -140 in the higher VDSL2 range.
In your graphs, they show about -130 in the ADSL range, then -100 to -120 in the higher range. This suggests a fair degree of extra noise.
The shape of the QLN graphs is, I think, significant too. The general shapes are pretty similar - suggesting that your additional noise is coming from throughout the spectrum pretty consistently. My guess is that this would be more likely to come from crosstalk from another VDSL2 system rather than being interference.
I recently moved, and had an earlier FTTC line. That one was 650 metres long, and could only sustain 36/10 on the 8c profile (due to errors), but jumped to 40/10 on the switch to 17a. The modem predicts a maximum of 59/16.
The line stats for the original line
show a few differences. Because of the distance, I can understand that the bit loading stops before the end of the D3 frequency band. However, the bit loading from tone 1250 upwards is very similar.
The thing I don't understand is why the bit loading is so much higher up to tone 1000 in that first line. Very strange....
That line too shows noise values in the region of -120dBm to -140 dBm. The only difference is that it seems to get quieter, but at the same frequency point where the signal can no longer carry any information - presumably the interference (crosstalk) can't be carried the same distance either.
Against those 2 graphs, your noise levels are definitely looking to be the problem, and throughout the spectrum.