Recent speed decrease - actionable?

Hi, After experiencing a recent broadband speed decrease I'm wondering whether its significant enough for me to be able to get BT to do anything about it.


Knightwick exchange (WMKNI) cabinet 4
We got FTTC (BT Infinity) back in October 2016. Speed then was 30 down & 10 up and was around that figure until 1 month or 2 back. Even higher at times - I recall 33 down from time to time I checked.


Recently its dropped to 25 down (latest test).

BT Wholesale speedcheck now says 23.75 down, 14.01 up (!) and 33 ping.

BT ADSL checker for my line / postcode says VDSL Range A (Clean) 30-41.4 down 6.1-8.3 up and handback threshold 26.7 / VDSL Range B (Impacted) 20-
32.4 down 3.7-7.4 up and handback threshold 15.5

The decrease is noticeable just through general internet use, and when using bbc iplayer.


We've had line problems previously (back in 2015) so I suspect its that again. But is the speed decrease significant enough to get them to come out and investigate fix / or will they now say its an impacted line and so within acceptable range? Can a clean line be reclassified as an impacted line "just because"?

Cheers for any advise

Not sure anyone pays attention to the clean versus impacted really

It might just be more cross talk, or could be a line fault, the speed test does not suggest lots of errors impacting smooth flow of TCP traffic, i.e. a nice result.

Ignore the BT Wholesale speed test as it has some quirks of late

The key is what were the attenuation, sync speed and noise margin figures from the modem, before and after.

Cheers. Unfortunately, I haven't kept stats from the hub (BT SmartHub 6). Currently it shows the following. I'll keep track of the figures and see whether it continues to degrade.

Data rate: 8.50 Mbps / 29.03 Mbps
Maximum data rate: 8367 / 28559
Noise margin: 4.9 dB / 5.7 dB
Line attenuation: 25.8 dB
Signal attenuation: (no figure shown)
VPI / VCI: 0/38
Modulation G_993_2_ANNEX_B
Latency type: Fast Path