Help understanding VDSL line status

Hi all,

I'm having problems with a VDSL line - intermittent slow downs. Speeds drop from usual ~60Mbps/16Mbps to 2Mbps/0.5Mbps and this lasts for 20-30 mins.. These occur about 2-3 times a day now. I have replaced master socket & disconnected extension wiring - the only device is my Draytek 2860 router, which I have also replaced and had config verified ( its very simple anyway)... I've also disabled the Wifi and have only my PC connected to the router. The router has some stats on it and I'm hoping someone could help me understand if the problem is actually further upstream. Here is the "DSL Status" data:

ATU-R Information
Type: VDSL2
Hardware: Annex A
Firmware: 05-07-06-0D-01-07
Power Mngt Mode: DSL_G997_PMS_L0
Line State: SHOWTIME
Running Mode: 17A
Vendor ID: b5004946 544e0000
ATU-C Information
Vendor ID: b5004244 434da48c [BDCM]
Line Statistics

Downstream Upstream
Actual Rate 48999 Kbps 14996 Kbps
Attainable Rate 58579 Kbps 17047 Kbps
Path Mode Fast Fast
Interleave Depth 1 1
Actual PSD 7. 5 dB 13. 5 dB

Near End Far End
Trellis ON ON
Bitswap ON ON
ReTx 1 1
SNR Margin 8 dB 6 dB
Attenuation 19 dB 24 dB
CRC 542 80494
FECS 0 s 698930 s
ES 96 s 9105 s
SES 20 s 3533 s
LOSS 0 s 0 s
UAS 26 s 31538 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 32 32
RFEC 16 16
LYSMB 16 16

Compared to 2 other Drayteks also on VDSL the "Far End" CRC, FECS, ES and SES values all look high... but I have no idea what they refer to.

Is anyone able to give me an idea of whether or not I should be asking my ISP/BT to check and maybe fix the line..? I can't think of anything more to do on my end in the house.

Many thanks for any help!!!!!!!!

Are the other circuits you mention at the same location as this line ?

Have you checked the line for audible noise ? (I expect this isn�t a noisy line)

I wonder if this might be intermittent REIN

If when things slow down the sync speed is unchanged then suggests not the VDSL2 but something else, unless the error counters are clocking up at very high rates at that time

Possibly a random thought, but I had very similar symptoms in the past if I turn on any of the additional security features on my Asus RT-AC66U router. Can't recall the exact names off the top of my head - probab;y all lumped in as their AiMesh features. Anyway, point being, if I turn the extras on, then about every 24 hours the connection throughput drops drastically to ~1Mbps. Having turned all of that stuff off again I've had no issues in several months of uptime. So it may be router related in your case too (though I'd expect Draytek to be better).

Both the upstream and downstream have been capped/banded.

From the stats you posted you are getting the actual rate but should really be getting the attainable rates.

ReTx is active up/down suggesting a noisy upstream.

Is be tempted to ask my ISP to request a DLM reset from OpenReach and see if that helps.

Edited by j0hn83 (Fri 15-Mar-19 13:35:52)