About 6 months ago BT upgraded my local exchange to improve the speed (MaxADSL ??) and my sync speed went from 7616 Kbps to 20535 Kbps with an improved IP Profile of around 18 Mbps.
Recently I've had a noisy line and got BT out to check it out but insufficiently noisy when they visited. They did fit a new (MK3 Master Socket) and then left. Over the last couple of weeks I've only been able to sync at 14336 and my IP profile is down to 12.65 Mbps. Line has been stable for 7 days now and I cannot work out why my sync speed/IP profile is still so low. SNR Margin (Up/Down) is 7.4/11.6 and Line attenuation 7.4/18.3 which I think is similar to when it ran at 20535.
Any suggestions gratefully received.