My line attenuation is exactly the same as yours on my HG612. On my old TP-Link Archer used to say 12db.
I'm at least 300m away from the cab, just not sure the route of the line as this house was one of the last finished. It's all underground.
BT checker says Clean 79.4 to 56.2. Impacted 77.1 to 52.5.
My cabinet is located in 46 Frostic Walk, Shadwell, London E1 5LT
https://www.google.com/maps/dir/Bishopsgate+Telephon...
Just for my own security I did not include my home. Just cabinet location and BT Exchange location.
As you can see Bishopsgate Telephone Exchange, 20 Jerome St, Spitalfields, London E1 6NJ in my case takes a route via Brick Lane and then back to 46 Frostic Walk and from there to my home via Wentworth Street. This artificially increases the length of the copper travel. But if we were to include this route to my home from exchange it becomes 960+ meters to home with ADSL pure copper and add 40 meters and it's like 1000 meters.
When we exclude the telephone exchange and only connection from the cabinet to home that is around 290 meters. The way I do this is by calculating the length of copper from cabinet to exchange which is 0.4 miles ~ 644 meters. Now that would be around 644 meters of Fibre traveling from BT Exchange to the cabinet and the rest of the 300 meters is copper to my home.
This is probably not the most accurate estimation of the measurement, but it is very close and is reflective of the speeds I am getting.
So far my line has been like this...
Line 1
Downstream Upstream
Actual Rate [Kbps] 80000 19999
Maximum Rate [Kbps] 80534 19999
Noise Margin [dB] 5.90 15.00
Attenuation [dB] 17.90 0.00
Power [dBm] 13.00 7.60
My Internet Connection
Status
Connected
Current speed
Download
80.0 Mbps
Upload
20.0 Mbps
Connection up-time
Connected since 15d 11h06m41s
Noise margin has been stuck to 5.90dB and has not returned back to 6.40dB. Only positive is so far 15+ days stable connection uptime. This has never ever been the case with ADSL. With a 6dB profile on ADSL my connection would drop-out 2-5 times a day! But here via FTTC now it has been a good 15 days so far. As long as those noise margins don't yo-yo too much connection should remain stable for a long time.
I'm glad I am getting these speeds. Because my management team have refused to grant wayleave to Hyperoptic for FTTP.
If your figures are showing 79.4 you should be getting that at least in your router stat unless you are suffering crosstalk or some other issues such as router.