For the record I have just had 2 disconnections in rapid succession following nearly 10 hours of stable line (a rain storm has now caused a recurrence of my noise problem) resulting in 0.3db increases in noise margin each time. The first resync at 1024 dropped out after 2 mins and I am now syncing at exactly the same speed as I have been all day (5mbps) so the noise margin seems to be making very little difference to this. My profile remains at 135kbps (according to www.speedtester.bt.com), this is about 16 hours after I got a poor sync speed this morning.
This is current normal behaviour and I only need to hold my fingers crossed for another 116 hours that I get to avoid a go slow.
I'm just logging things as I'm finding them so that people can see how things happen and what they might expect. (And I admit, getting a little of my own irritation off my chest although I can see the technical reasons for the way things happen.) There's one or two ranters out there who are bullying customer services to do some random things because they can and not actually getting things sorted for themselves.
My only point is that persistently getting your noise margins or any other value reset is only of very limited value if you have a line problem that needs to be fixed and that there are some people who have reported doing this, which may suggest to other users that this is an appropriate way forward. Why should I not try to deflect some of this and spare both the user who is pinning their hopes on a short term "fix" that won't ultimately work and a poor customer service agent who might be able to come up with some useful advice?
Which is only going to cause problems if people think customer services should be doing something (like performing REPEATED resets) and then getting cross because they won't do something the customer feels they should be, where other customers have reported being able to get BT to do it. In my line of work I have to manage people with unrealistic expectations on a regular basis and it is not a lot of fun.
Before I went on a similar tangent myself I thought I would calmly "show my working" as it were and try to give a realistic timescale of how things were happening and then perhaps I would be able to discern if, for example, I did have a stuck profile or was simply having a normal experience with a less than perfect line.
you have presented a clear overview of your particular case in which the DLM seems to penalise you unduly, I cannot fault your reasoning.
The 'new system' of DLM would appear helpful in your case, and many others, but most of us don't know when this will be applied to us.
On the other hand, you do appear to have an intermittent line fault and should be able to have this investigated and rectified (normal UK weather other thsan thunderstorms really should not cause sigificant changes to your sync / profile), I'd personally ask for a physical line check as there is probably a poor joint somewhere causing your underlying problems, only if this gets fixed will you enjoy the broadband your line should be capable of.
So just to round this off. I currently have an IP profile of 135kbs and it has not improved for several days - I am not cross about this because I have been able to gain an understanding of why it is happening due to using these fora and other internet resources.I obviously will be very grateful if the new profiling system rolls out sooner rather than later.
Checking the Error log on my Homehub3, which is found under the "Troubleshooting" tab on the Hub Manager, I am able to see that starting around 2 am there were multiple disconnections. One of these was down to 160kbps for about 19 mins. This will explain why my profile stays low. I do not know why these happen then, whereas during the rest of the day, on a similarly noisy line, it is pretty stable.
I will be calling out the engineer again because there is a lot of line left to explore for faults but given the timescales some of these have taken to resolve looking at these fora I am likely to spend a lot of time giving the next occupant of this house perfect broadband.
If this persists after the next week or so I will try turning my hub off overnight (with a noise margin of 16db I can hardly make it much worse) and try to avoid these periods - I will let the fora know if this is a successful workaround.