OK - colour me confused. I keep hearing that IP Profile, under DLM is a dynamic entity, and that it can go back up once it has gone down.
The story so far:
On install day, the guys came, installed and saw an IP Profile of 60.1 down, 20 up. That stayed rock solid throughout the 10 day settling-in period. Never moved. I never saw anything above a 16Mbits upload speed, but that's fine.
Then, 10 days ago, the electricity failed. Not once, but four times, in the space of an hour or so. It would come back up, everything would start back up, and then it would go down. After the fourth restart, I was concerned that my IP Profile would have been compromised - and I was right. Down to 56.29 it went.
"No matter", I reasoned, "DLM will see what's happened, and will bring it back up to the 60.1 it was stable as a stable thing it was".
It hasn't. 10 days on, it's stuck at 56.29. Now, I'm not whinging about the actual speed - it's still very fast, and I can state with some certainty that we rarely, if ever, max it out. No, what concerns me is that the line was very obviously stable at 60.1, and nothing else has changed - just the connection being forced to drop four times in an hour. Patently, DLM CAN go down - but it appears not to be capable of going back up.
As I say, at the moment, things are fine - but I'm more than a little concerned that, at some point in the future, DLM's going to read something as beinga line probem, drop me down to something untenable and then not come back to its proper level.
I'd really like to get the definitive answer to all of this - I have read the theory, but the practice seems to be at odds with it. My situation doesn't warrant a boost engineer's visit, but it would be awfully nice if, after a disconnect, the connection re-trained from 80 and settled from there - and that's not beyond the wit of Openreach to implement.