Has PN reduced my Line speed?

[#1]

My BT HG2700 router is synced at 3552.
speedtester.bt.com reports my line profile as 3000 (what you would expect with that sync speed)
PlusNet report my line profile as 2000 (reducedon the BT report)
Runnning a speed test, best performance is 1828 (consistant with a line profile of 2000)
Last weekend I found exactly the same situation. I rang plusnet customer services who reset the plusnet line profile to 3000.(which is what it has been for as long as I can rememeber)
This weekend plusnet have wound my line profile back down to 2000 again.
Checking my router logs I cannot see any re-sync apart from the manual one that I did this afernoon when I power cycled it.
Can anyone suggest why the PN system keeps winding back my line profile, or what can be done to keep it at 3000 which is where it has always been until now?

[#2]

PN set the figure based on what BT supply them with in the BRAS profile report, they do not set it themselves except sometimes when the package is changed or they switch you to the new 21CN network .
So BT have reported the IP profile as needing to be 2000 at some pont earlier and the new figure has not been processed yet or BT have not supplied an updated BRAS profile report yet. Why this has happened is impossible to know but others have reported seeing the figure drop with no apparent re-syncs being seen.
Best to raise a ticket and get PN to investigate and see if it was a BRAS profile figure that changed it or a fault on their side. Don't just accept them raising the figure again.

[#3]

Sorry I am not quite clear on this.
The result shown on speedtester.bt.com (3000) is not the same as the BRAS profile?
PlusNet set my line speed to match the BRAS profile which you are suggesting is probably 2000?
As an end user is there any way I can find out what my BRAS profile is?
Here are my router stats;
Sync Rate 3552
Noise Margin 15.1 dB
General Information
DSL Line (Wire Pair): Line 1 (inner pair)
Downstream Rate Cap: 8128 kbps
Downstream Atten. at 300kHz: 52.2 dB
Uncancelled Echo: -10.9 dB Ok
VCXO Frequency Offset: 13.3 ppm Ok
Final Rx Gain: 33.7 dB Ok
Impulse Noise Comp. Tones: 0 Ok
Excessive Impulse Noise: 0 Ok
Impulse noise protection:  1.07
Delay of latency path:  8.00 ms

All of which looks normal for my connection, but it seems to be being throttled back.

I appologise that you have offered me some much appreciated advise and I have come back with a load more questions. Years of relatively trouble free service from PN has meant I have never had to learn about how the service operates on a more technical level.

[#4]

The 3000 figure on the bt speedtest is what is currently set at the exchange - it is normally refered to as the data rate or IP profile rate. That along with other information is sent to PlusNet in a BRAS profile report daily or twice daily I think. PlusNet then process the report and set the figure on their systems which is what you see under high speed broadband.
So at some point either BT have sent PN a BRAS profile with a figure of 2000 in (which PN then set on their systems) or something within the PN systems has set it independently of the BRAS profile figure. It is the reason or cause of this you need to get PN to investigate. If they say it was BT that told them then it was not their fault. If it was done by PN themseleves then there must have been a reason for it. In either cause you need to raise a ticket and explain the situation so they can investigate.
The IP profile system that BT use is a right pain in the A* and causes no end of problems. Any minor blip on sync rate or at BT's whim and they knock the IP profile figure down and youthen have to wait many days for it to recover even though you may have resynced seconds later at a higher/original figure. BT ay their systems are intelligent and will recover quickly but I have never seen that happen. I am currently in the same situation... I sync at just over 3000 but my profile is 2000. This is because for a few seconds I rebooted my router at a lower figure and BT reset the IP profile accordingly regardless of the fact that I resynced seconds later at over 3000. It was much much better on Tiscali wholesale LLU where you sync rate was your data rate - simple and straightforward... no problems messing about with BT's faulty profiling system

[#5]

Thanks for explaining Peter.
I have followed your advice and raised a ticket.