BT Broadband - Open letter of complaint

Prud

Thanks for the help, I hope this is everything you need.

ADSL settings

ADSL settings

VPI/VCI 0/38
Type PPPoA
Modulation ITU-T G.992.1
Latency type Interleaved
Noise margin (Down/Up)9.1 dB / 17.0 dB
Line attenuation (Down/Up)53.0 dB / 31.5 dB
Output power (Down/Up)17.2 dBm / 11.9 dBm
Loss of Framing (Local) 0
Loss of Signal (Local) 0
Loss of Power (Local) 0
FEC Errors (Down/Up) 32662497 / 132
CRC Errors (Down/Up) 433 / 2147480000
HEC Errors (Down/Up) nil / 93
Error Seconds (Local) 427

kwikbreaks

For some reason that set doesn't show the sync. Ideally all are needed at the same time.

Anyway...
Modulation ITU-T G.992.1 is plain upto 8Mbps ADSL and not ADSL2+ which is upto 24Mbps (but often sold as upto 20Mbps). On a line of your length though ADSL2+ wouldn't offer any huge benefit anyway.

Noise margin (Down/Up)9.1 dB / 17.0 dB
The default downstream margin is 6dB so yours may have been elevated because of some instability. If you reboot the router and check immediately after it has synced if it is still ~ 9dB that would confirm this. If it was elevated from 6dB at the time your speed dropped then this is the cause of the drop in speed as higher target noise margins result in a lower sync rate.

Line attenuation (Down/Up)53.0 dB / 31.5 dB
This says you have a moderately long line. I'd expect to see a sync of around 4Mbps with this attenuation and a 6dB target noise margin.

Errors
FEC errors are corrected and pretty much par for the course on interleave and can be ignored
Upstream CRC errors look to be incorrectly reported (that huge number is really a negative number)
Downstream CRC and errored seconds may or may not be high depending how long the router has been up and that isn't shown in those stats.

There is nothing remarkable about your stats - some high noise event has resulted in an increased target margin (possibly something as simple as you pulling the phone plug on the router rather than powering it down). That coupled with the banding of IP profiles by the BT system is probably why your speed fell. It may (or may not) automatically recover over time.

With TalkTalk LLU you wouldn't suffer from the BTw line management routines and would probably revert to the sort of speeds you were getting with BT. I seriously doubt that you'd better 4Mbps. The problem with TalkTalk isn't their technology - it is their abysmal customer service record when things go wrong. You gotta ask yourself punk - Do I feel lucky?