Thanks Roberto, I know my BQM is horrible!
But why? I've heard of one other person, who had a similar (undiagnosed) issue on the 8c profile, which was cured on the move to 17a. Mine is the other way round, packet loss was clear before the 17a change, then appeared immediately after the resync. But as I achieved no overall speed increase, I can't figure out why? And why do testers show zero packet loss?
Wow - that's bad. I had the same kind of picture on the first 2 days on 8c, though the peaks were nearer 10% and the average under 5%.
DLM obviously intervened after 2 days, added interleaving (which fixed the packet loss entirely) and then (a few more hours later) dropped the speed from 40 to 36Mbps.
Without the hacked modem at the time, I can only guess that I was getting a high number of CRC errors in the first 2 days, which DLM could see and act upon, but that 4% of the pings (carried in ICMP) were dropped. I guess further that the switch to interleaving also turned on FEC, which lost the CRC errors and fixed the packet loss. I don't think I needed the drop in speed (the line worked perfectly with profile 38717 alongside interleaving for perhaps 10 hours), but I guess that went alongside DLM's choice of profile for the line.
I therefore wonder why DLM isn't doing the same to your line, and obviously wonder whether the Fritz is managing to do some to subvert DLM - perhaps by not reporting the CRC statistics back to the cabinet DSLAM.
I think you posted some error stats, so I'll go check those & respond...