Apologies to the OP for this being OT but I couldn't see an easy way to split the thread without making some replies nonsensical. It was purely to show b4z an example of how FEXT affects a line that I posted my stats. Then it was only because I did this... that I happened to notice the changes in my power profiles last night.
Re. Kitz' comment. If you hadn't drawn my attention to your SNRM plot I probably would not have made any deduction on the absence of the typical oscillations that you experience in such circumstances.
I appear to have picked up a different PSD mask with different power levels. It is at this point I miss the demise of MDWS so you can see some stats which dont appear on DSLstats. I've noticed for a while that since the advent of Dynamic Spectral Management (DSM) that on occasion users can be allocated different power profiles. On certain profiles my line seems to behave better when it comes to my 'familiar' oscillations. I've also noticed that users can be allocated higher power levels if they sync before their disturber comes on line and this profile will stick even when the disturber comes online until you next resync.
What I was trying to say is that quite often lines (not just mine) can on occasion see a boost in power levels depending what disturbers are online at the time of EU's sync. Past experience has taught me that if I resync now, then not only will I lose the increased sync speed from the SNRM, but I will lose my existing power profile and upstream power will reduce back down again.
If it is the case that DSM controls your power profile (which by all accounts it should do... and awaiting any feedback from ejs) then that may explain why I can't seem to shift the oscillations unless its a remote sync which also knocks my disturber off line.
Whether it was cabinet work, work on the fibre back-haul to the fibre head-end exchange or work at the fibre head-end exchange, the timing, etc, has all the hallmarks of planned engineering works. The fact that all circuits terminated on the DSLAM were triggered to perform a re-train seems to suggest that there might have been a software upgrade during the service outage.
I can't see any evidence of a software update to the line card. But this is the 2nd time in the past 2-3 weeks that I've lost some sort of (BTw) backhaul connectivity followed by a DSLAM initiated resync. Whatever it is will cause internet interruption between the point of DSLAM and my ISP. A tracert on both occasions stopped before I could reach my ISP yet I would have sync. If I tried to force my router to do a PPP reconnect it would fail to pick up an IP and return 0.0.0.0. It's my understanding from theory learnt in days of old that if it was an ISP failure you would at least be allocated with an internal BTw IP address even though your routing wouldn't go anywhere near the Internet this BT internal address would at least allow you to perform certain diagnostics such as reach the BT digital realm test sites* The fact that I couldnt even pick up a BTw based IP leads me to think the point of failure was before the bRAS and therefore between the DSLAM and head-end exchange.
[wishful thinking]
Could G.998.4 have been rolled out to your cabinet's ECI M41? 
[/wishful thinking]
Wishful thinking indeed. G.INP is and always has been a 2 step process.
1.) DSLAM configuration changes - These are DLM profiles which are set on the DSLAM and not any f/w upgrade.
2.) EU DLM profile roll out which are applied to the individual line profile. Historically on Huawei cabs & the botched ECI roll outs 1) always happens a few weeks/month before 2).
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*It's because BT use an internal IP that is in the same range as supposedly used by the CIA, that started conspiracy theorists down a rabbit hole.
I know for a fact that BTw has always used this specific range of IPs if for some reason you cant get internet connectivity to your ISP. It was built like this since at least 2003 that I have seen, so that you can at least access the BTw digital realm for tests and start-up domains if connection to your ISP fails and the bRAS can't pass you on to your ISPrealm.
iirc AAISP RevK also confirmed this more recently. But I definitely remember 10+ years ago when Plusnet had their Broadband plus accounts and BTw policing the central capacity EU numbers, so that users would find themselves unable to connect to a PN central and end up on the BTw realm with one of their IPs.
