Speed loss advice please?

My line has been syncing at 80/20 for nearly 2 years.

A few months back I was subjected to DLM hell as a result of rebooting too many times, but BT decided there was a fault and swiftly sent an engineer who swapped me to a different pair, reset the DLM and all was well...although my upstream dropped a bit. I wasn't too bothered and very pleased at the swift response.

But about a month ago, my downstream sync dropped first to 70 then to 60 in the space of a week Upstream sync dropped to 3.5-ish! The "Max attainable" rate is still 94 downstream which is what it was before...but only 6 upstream, down from 20.

And to add insult to injury, I've been Interleaved.

The IP Profile is 59 or 60Mbit/sec down according to the speed tester (I forget the exact number and it isn't currently showing IP profiles due to some error or other.

I don't think this has anything to do with G.inp as I'm on an ECI cabinet, and the problem doesn't go away when swapping the ECI modem for a Huawei, nor when using my Draytek router's built-in VDSL modem.

The only stats I can share are from the Draytek itself. I'm not sure if they will format intelligibly, but they are posted below.

My question is -- realistically, is it worth getting an engineer to take a look, or am I just going to end up with an SFI bill and no improvement? A drop of 20% down and over 50% up seems quite a bit to me - something isn't right, especially as it happened in the space of a week. But it isn't internal - I've swapped filters, cables, modems, and there are no extensions, nothing new going on within the premises.


Downstream Upstream
Actual Rate 59717 Kbps 3608 Kbps
Attainable Rate 94890 Kbps 6103 Kbps
Path Mode Interleave Interleave
Interleave Depth 1685 82
Actual PSD -4. 0 dB 18. 5 dB
Near End Far End
Trellis ON ON
Bitswap ON ON
SNR Margin 10 dB 8 dB
Attenuation 8 dB 0 dB
CRC 53 439816
FECS 263189 s 24013586 s
ES 8 s 304774 s
SES 0 s 3 s
LOSS 0 s 133 s
UAS 32 s 33256 s
HEC Errors 0 0
RS Corrections 0 0
LOS Failure 0 0
LOF Failure 0 0
LPR Failure 0 0
NCD Failure 0 0
LCD Failure 0 0
NFEC 49 56
RFEC 16 16
LYSMB 1466 21504

Attenuation is low and in line with the attainable figures, so looks like DLM has gone a bit mad on you. There are errors being corrected by interleaving and it may be the volume at faster speeds is high enough to cause issues, i.e. this could just be really bad case of cross talk.

Oddly, within 24 hours of posting, my download sync went up a little - to 65. It has gone up a bit on the upload too, but insignificantly.

Maybe I'll leave it a little longer and see if it completely recovers.

I'm still bothered about the massive difference in upload speed on this pair compared to the old pair though.

Dag nab it - I need fibre