Agreed. The first thing that came to my mind was a new crosstalker. There isn't much you can do other than hope the vectoring is enabled on the cabinet, but I doubt OR are enabling vectoring now that they're focussing on FTTP.

Thanks all.

I fear a bad cross-talker is the explanation. I am going to leave alone until the new year and then do as MHC suggests and eliminate an internal issue as the cause.

Fingers crossed for Vectoring but from a quick search online, it seems BT are focused on G.Fast rather than Vectoring (which appears to only be possible for Huawei cabs anyway). As for for my cabinet, it is not enabled for either and not in a FTTP priority area.

So it looks like I'm stuck with the reduced speed for the foreseeable future. I'll just have to keep my fingers crossed that the cabinet doesn't fill up further and introduce more cross talkers.

Are you able to go back through the data and identify the time and duration of the "spikes" where it went back to the original?


Edit to add:

I was probably the first VDSL customer on my cabinet and had some wonderful max attainable rates well up th the 90s and high 20s. As more were added it dropped slowly to around 80/22 attainable and then a littlke more - no great big steps and I am probably teh longest (except one) line. I knew it would happen and it was fine. Then, the big one arrived I cannot remember exact numbers but it was a 10Mbps hit ... we knew who it was and they turned theirs off, mine returned to normal, back on and mine dropped. When te house was sold and new people moved in, new equipment but still the same problem!

Edited by MHC (Mon 20-Dec-21 11:04:00)

In reply to a post by oracleredux:

Fingers crossed for Vectoring but from a quick search online, it seems BT are focused on G.Fast rather than Vectoring

Excluding a couple trials, Openreach only ever deployed Vectoring on VDSL2 on targeted BDUK funded Huawei cabinets.
They only used it where it increased the number of properties on a cabinet who could obtain SuperFast speeds/targets as their funding for these cabinets was linked to how many properties they covered.

VDSL2 Vectoring has never been deployed commercially by Openreach and it never will be unfortunately.
There won't be any more upgrades to the VDSL2 cabinets.

The G.Fast rollout is also long since over/dead.

The focus is 100% FTTP.

But installed G.Fast is still live and reported on these forums a bit ago as preventing FTTP being installed for now whilst some more distant FTTC on the same cabinet is getting FTTP offered as an upgrade.

AIUI G.Fast requires vectoring to be enabled on at least the pod DSLAM.

I said the G.Fast rollout was over/dead.
Existing G.Fast remains in place, though the number of providers selling it is going down, not up.

Vectoring is mandatory on G.Fast.
That provides zero benefit to VDSL2 though.

I don't doubt your expansive knowledge John, but are OR really focussing 100% on FTTP, as an FTTC cabinet is planned to be installed in a local town to me?

Edited by Grimers (Mon 20-Dec-21 17:40:16)

They are still installing FTTC cabinets, though few and far between.
They are even still installing the odd G.Fast pod.

The Scottish R100 programme plans on using FTTC to meet some of its targets.

I said the focus is 100% on FTTP, not that they are only installing FTTP.

There is no current VDSL2 or G.Fast rollout programme, though they will continue to use them on a small scale where appropriate.

In reply to a post by MHC:

Are you able to go back through the data and identify the time and duration of the "spikes" where it went back to the original?

Happy New Year. I've gone through the data and these are (table extract) the times and duration of the "spikes".

One for a minute a couple of days after the original decrease in SNR, the same the next day, both overnight (offending modem resync?). Then 10 minutes in the middle of the day in early December and a couple of longer periods a few days later.

No discernable pattern that I can see. Have yet to turn everything off and isolate stuff my side of the meter but I fear it's as j0hn83 suggested and the same as MHC has seen - a crosstalker.

Edited by oracleredux (Thu 06-Jan-22 23:05:02)

My G.fast was pretty very good with vectoring!

Latest Stats as of now:

Stats recorded 07 Jan 2022 06:09:17

DSLAM type / SW version: BDCM:0xc190 (193.144) / v0xc190
Modem/router firmware: AnnexA version - A2pvfbH043q.d26u
DSL mode: G
Status: Showtime
Uptime: 7 days 3 hours 36 min 22 sec
Resyncs: 0 (since 07 Jan 2022 05:29:00)

Downstream Upstream
Line attenuation (dB): 37.8 0.0
Signal attenuation (dB): 37.8 0.0
Connection speed (kbps): 241117 41527
SNR margin (dB): 3.1 3.1
Power (dBm): 0.0 4.1
Interleave depth:
INP: 550.00 607.00
G.INP: Not enabled Not enabled
Vectoring status: Unknown

RSCorr/RS (%): 0.0364 0.1037
RSUnCorr/RS (%): 0.0000 0.0000
ES/hour: 0 0