BTO Setting Lower Profiles?

[#1]

My speed has reduced recently, and I have had over a week fixed at a lower speed to normal.
Talking to PN today, a lower speed has been set on my connection, it seems, so a fault seems unlikely. PN have not done this, it seems.
It appears that for some reason BT have put me on a lower profile, or so I'm led to believe.
Do BTO do this? Deliberately Cap you at a slower profile in the cabinet, or exchange? Why would they do that? Capacity issues? I can't see our street cabinet being oversubscribed.
DLM didn't seem to be involved.
Has this happened to anyone else?

[#2]

My speed has dropped off this last week and my profile had gone down from 40 to 36 with no apparent reason.
It's been fine for the last 6 months but have now raised a fault.

[#3]

@danludlow
DLM is always monitoring the line, so any changes to reduce the speed will come based on the DLM logic.
Looking at your line there have been several disconnections since the 5th, which ties in with the timescales you've been seeing lower speeds. Now there hasn't been a huge amount of disconnections, but these could be caused by a number of factors so if the line continues to disconnect and the speed doesn't increase it may be worth opening a fault for us to look into.

[#4]

I've raised a fault for my speed and profile drop - let's see what happens!

[#5]

Thanks for looking into this Chris. Some of the disconnects would be me, but some aren't. I reset my Router a few times in that period, I also saw the connection drop on Friday for about an hour, and some 15-20 minutes after it returned, it dropped again for about 5 minutes. I assumed this was BTO, and have seen BTO in the village at addresses attached to my cabinet. Presumably if the signal is lost due to engineering it simply registers as a fault with DLM.
Also, presumably, if my connection remains stable, speed will return?
Any idea how long this could take?

[#6]

It can take anything from days to weeks It's also not uncommon for it to take over a month or more for DLM to deem everything ok and increase speed and that's IF DLM deems things to be ok to want to do anything positive in my expereience it tends to do more bad than good I hate the damn thing.

[#7]

Do you think it would be worth me rebooting the modem?  I'm not aware that the power has been off, or had any other issues with it, but my profile has dropped 10%.

[#8]

Rebooting the modem wont do anything to get speed back there is no way to alter what DLM does by a user ie rebooting the modem or by Plusnet only a BTO Enginner can reset DLM and they only do that if they have to physically fix the line or any hardware at the cab / exchange,  i have gone from a 65Mb down to 50Mb so i feel your pain sadly nothing can be done your at the mercy of DLM,  as Chris says if you keep disconnecting then you should raise a fault other than that your stuck with what you have. 

[#9]

If there's one subject that keeps recurring WRT FTTC, its speed issues. Maybe this is paranoia and we should be happy with what we get, or just maybe speed is a serious issue?
Today's budget statement that every address will at some stage be connected to100Mbps (minimum?) Broadband connection rather bears out the importance being placed on faster broadband in the future.
New technology will help this, no doubt, but in the meantime we have what appears to be an unreliable system of unknowns. Speeds fall, they rarely go up, all kind of reasoning is given as to why the speeds cannot be maintained, and what can affect speeds. In many other areas of life "see what you get" on a day to day basis would not be acceptable, reasons would be sought, solutions would be devised and implemented. Maybe they are being, as I type this.
What is certain is that in BTO's DLM, there appears to be a very lop-sided set up. A connection is seen as unstable and reduced by applying measures as befits, and more or less instantly. It appears that it cannot, (or does not) consider prevailing circumstances when it steps in (there may have been a thunderstorm, or a gale locally with power drops and power cuts, but a connection is seen as unreliable and DLM intervenes). WHY, if DLM can react quickly to a bad connection is it so damnably slow reacting to a clear line, and in some cases (all cases?) unable to restore speed to original levels?
The cynic in me says that its set up that way to the benefit of BTO rather than the customer. I have come to loathe the initials DLM, perhaps unfairly, but looking at the many posts, it seems that DLM is a factor in many speed issues, and speed issues are the greatest factor in customer's annoyances.

[#10]

DLM doesn't set the speed - other than introduce banded profiles. Generally though and with recent DLM changes, it doesn't need to put you on a banded profile unless the line is very noisy.
There are people on here blaming DLM for reducing their sync speed when they are on high downstream profiles. This isn't DLM doing this...

[#11]

Quote from: AndyH

This isn't DLM doing this...

Who or what then put me on Interleaving and my speed dropped?

[#12]

Interleaving is DLM.
Line speed dropping can be DLM (putting you on a profile) - but normally this is the line self-adapting to meet the target snr of 6dB. If Plusnet tell you what downstream/upstream profiles you're on, then you can see whether the speed drop is the line rate adapting on its own or due to a DLM enforced speed profile.

[#13]

Thanks Andy in confirming I'm correct in blaming DLM, it put me on Interleaving due to electrical maintenance here today turned the power off to modem and router.

[#14]

Based on your posts, I would suggest interleaving was turned on before today...

[#15]

No idea Andy I have only the info. given from the speed test sites, speed and ping, not much info. is to got from the Sagecom router 192 but I suppose it is the info from OR Modem where it will be and I think that is Locked.
After first 36 hours at top speed DLM took me into the area of Estimate and after power down another drop.