Thanks to a helpful guy at work (who frequents these forums - small world) I've discovered that the cabinet I'm connected to was upgraded to handle more connections in 2018 which is rough when things started deteriorating and confirms crosstalk is likely to blame. Its looks like just a few roads from the cabinet don't get 30Mb so my area is probably low on the list to get FTTP - https://www1.telecom-tariffs.co.uk/codelook.htm?xid=...

I've tweeted openreach help in case I can get anywhere but looks like its second line, FTTPoD or sucking it up

Do you have a filtered faceplate?

Running a VDSL service on an extension and/or on a master socket that does not have a filtered faceplate or if a standard socket does not have the bell wire removed can certainly impact the sync speeds.

To quantify this, I have an old style BT master socket, the type without a filtered faceplate. Initially the bell wire was connected (the orange wire) and my VDSL was running on an extension elsewhere in the house.

Since cleaning up the wiring, remove the bell wire and plugging the modem into the master socket I gained about 8Mbps. I actually also gained another 2Mbps just by switch out the supplied modem for a highly stable TP-Link TD-W9970. I even noticed about 1Mbps gain just for using a very short flat RJ11 modem 26 AWG cable.

So there are plenty of small wins IF you have the old style socket. If you have a filtered faceplate then of course the gains are limited.

P.S. just this week I realised my home plugs that I use caused quite a bit of interference. I have always been on fast path, but since using the home plugs over the last year, I was switched to interleaved, loosing about 5Mbps. This week I stopped using them, SNR Margin is now rock solid and I suspect I will be back on Fast Path soon, with a nice speed bump.

Edited by oldskool (Tue 11-Feb-20 19:25:28)

Thanks for the reply. Unfortunately I do a modern spilt faceplate with built in filter. It was installed in 2014ish when my cabinet was fttc enabled. The VDSL cable is little poor so maybe could be replaced but is only a year old like the router? I've recently read power line adaptors can mess with VDSL when they get older. Mine are 5 years old so I'm going to try without them for a bit.

I too have had a slowing FTTC. Our cabinet was upgraded to FTTC about 3 years ago, and I had a solid 30-32 mbps download speed (with a'guaranteed' 28-30 mbps speed from BT). Then about 3 months ago it started dropping - when it got to 26mbps I raised a ticket with my supplier, who stated they could see a fault on the line and that BT/Openreach would deal with it. An Openreach engineer then visited my house, ran the BTW test (which I had also been using) and told me everything was fine and that I shouldn't expect more than 23mbps anyway due to my distance from the cabinet. The fact I had a solid 30+ speed (plus the stats to prove it) was waived away as an anomaly. Within 3 days that speed has fallen further, to give 20 mbps (just). Another engineer visit - this time by a senior engineer - and I was told I could only expect 18mbps (as shown by the latest BTW testing) due to distance. However he had a look at the cable outside the house, and found it full of dead spiders, moisture and bare wires. Cleaning it up gave me back 26mbps, and he went off to do further work on the cabinet. Then my phone line went off - so no broadband at all either. Two days later I got my phone, - no apology - and speed back up to just under 30mbps. BTW also shows an expected speed of 28mbps. SO......... Speed seems to be lap of gods stuff - and openreach have no more idea what should be happening than I do!