Reduction in Synch Speed

[#1]

I recently had a reduction in synch speed from at 41 to around 37.  BT speedtester constantly reports that download speed is outside of limits (although only just), line tests out OK and this is confirmed by BT engineer - any ideas?  I used to synch at 43 ish just over a year ago when I was first connected, original estimate was however 57.1 which I never achieved and was soon after revised downwards by BT, so now a drop of about 14% since going on fibre.  I know that the speed drop is comparatively small but it concerns me as my starting point was lower than most and there seems to be a definite downward trend.

[#2]

Hi Muttley62,
Sorry to hear about the slight drop in speeds. I've replied to your fault ticket in more detail about this.
For the information of others that might be reading I've advised that the slight drop may be due to increased uptake by other customers on the same cab but to keep a close eye on the situation in case the speeds drop any further as what I've just mentioned shouldn't have a significant impact on download speeds.

[#3]

Adam please look at the screenshots that I have posted earlier from the BT speedtester, how can the acceptable range of speeds be from the IP profile as the minimum acceptable speed  to 40 Mbps as the maximum?  I thought that the IP profile would be the maximum acceptable speed - can you explain this?

[#4]

I guess it's just a bug in the speedtester originating from when the "minimum planned speeds" increased from 12Mb to 20Mb for 40/10 and 40Mb for 80/20.
If the 40 or 20 minimum planned speed is not possible due to your line speed being lower than that, the lower limit should probably be 70% of your IP profile.
Source: WBC FTTC Handbook, Issue 10, page 18