A few on here think the FTTC DLM is better than the ADSL system. It may well be.
But I think the FTTC DLM is more than just interleaving and banding, I think there is also power output control, possibly not even just to manage one line but is possible DLM is also monitoring multiple lines on a line card. All speculation on my part of course, but most mentioned on here is speculation anyway.
In terms of LLU, its my view the amount of complaints from people without DLM is lower than with DLM.
In regards to the IP profile remember thats not whats controlling the line speed, its just a throttle placed to limit the throughput, assuming its not stuck at a wrong level then it will be set slightly below the sync speed anyway. It was on adsl where the IP profile was a big problem. I agree I am not convinced its needed, there isnt many real world situations where a line would have out of control too much data going down it, the only situation I can think of is a denial of service attack. But here in this topic the IP profile isnt the problem, but of course since he cannot see his sync stats we can only guess why the speed is down.
BT Infinity 2 Since Dec 2012 - Estimate 65.9/20 - Attainable peak 110/36 - Current Sync 71/20