To me the original 14dB attenuation on upstream looks more suspect than the the current attenuation figures.
Issue seems to be Sky has played with the target margin on the upstream, and the downstream is just kit vagueries

Of course Sky never does anything to limit peoples speeds or so the paper work in the bumpf I get sent says so.

I will keep trying and will let you know outcome eventually.

They did mess about with it a bit early December to try and get a bit more out of it and to be fair it did run brilliant up till March, i like to keep a record of things so i can let you see some of the different stats i had -

22 december -

ADSL Link Downstream Upstream
Connection Speed 8603 kbps 1109 kbps
Line Attenuation 43.0 db 24.0 db
Noise Margin 6.8 db 7.9 db

26 december -

ADSL Link Downstream Upstream
Connection Speed 8392 kbps 1116 kbps
Line Attenuation 43.0 db 24.0 db
Noise Margin 7.1 db 8.1 db

30 december-

ADSL Link Downstream Upstream
Connection Speed 9100 kbps 1112 kbps
Line Attenuation 43.0 db 24.2 db
Noise Margin 7.1 db 7.9 db

and this morning its back down to -

ADSL Link Downstream Upstream
Connection Speed 5490 kbps 604 kbps
Line Attenuation 43.5 db 24.7 db
Noise Margin 12.3 db 16.6 db

Looks like to me assuming those last figures were grabbed ASAP after restarting hardware, that the target noise margin has increased, which will have reduced the sync speed.

If Sky reset the target margin back to 6dB for downstream then downstream will speed up, and similar for upstream. Welcome to Sky's DLM system.

ADSL Link Downstream Upstream
Connection Speed 9100 kbps 1112 kbps
Line Attenuation 43.0 db 24.2 db
Noise Margin 7.1 db 7.9 db

and this morning its back down to -

ADSL Link Downstream Upstream
Connection Speed 5490 kbps 604 kbps
Line Attenuation 43.5 db 24.7 db
Noise Margin 12.3 db 16.6 db

Now things are more apparent if that is the the correct terminology ,it's just sky's DLM /Mis-Management system which has borked your sync speed up, probably due to a bust of noise which produced a few thousand errors which probably would not of had any detrimental impact on your line, as suggested DLM can be a sneaky way to throttle customers connections, if on the other hand the DLM was reacting to a possible line fault then this should be investigated further by your isp,

The fact that sky will not remove DLM permanently from a connection if requested by the customer, is only one of many reasons i wouldn't use sky,
Although my line is fairly short if suffers with a interference problem from a property near to my home, this would trigger dlm and my sync would be crippled,

Edited by tommy45 (Thu 14-Apr-11 14:17:10)