I've had talktalk fibre service since last December, and it has worked 100% reliably until a week ago. I used to get 23MB down and 2MB up sync rates, with speed test results to back that up. A week ago my service went off completely - my Draytek router lost sync and couldn't reconnect. Now it work intermittently with my Draytek router, and reliably but slowly with the talktalk router (HG633).
I phoned talktalk support who did a line test and confirmed that there was a fault on the line. It was escalated to Openreach, issue ref no: INC000013346256, and my line number is in my profile. Openreach engineer came out (even though I'd called talktalk to cancel) and tested the line, said the measurements were all good. His test equipment synced at 20MB down and 2MB up, just like my Draytek router does. He also reset the line profile, in case DLM was affecting it.
My talktalk router will only sync at 0.5MB upload, which is clearly abysmal - I used to get 1MB upload on adsl. My Draytek router worked again for a couple of days (at 2MB upload), then lost connection and couldn't resync. Line stats from the talktalk router:
Type: VDSL2
Hardware: Annex A
Firmware: 05-07-04-03-00-07
Power Mngt Mode: DSL_G997_PMS_L0
Line State: SHOWTIME
Running Mode: 17A
Vendor ID: b5004946 544e0000
ATU-C Information
Vendor ID: b5004946 544eb204 [IFTN]
Line Statistics
Downstream Upstream
Actual Rate 19505 Kbps 1997 Kbps
Attainable Rate 24630 Kbps 2058 Kbps
Path Mode Interleave Interleave
Interleave Depth 817 26
Actual PSD 7. 6 dB 10. 1 dB
Near End Far End
Trellis ON ON
Bitswap OFF ON
SNR Margin 6 dB 6 dB
Attenuation 31 dB 44 dB
CRC 0 11670
FECS 9 s 44699 s
ES 0 s 6070 s
SES 0 s 0 s
LOSS 0 s 3101 s
UAS 52 s 315209 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 97 64
RFEC 16 16
LYSMB 613 6536