SPD,
It is wise to confirm from your ISP that if your broadband is "banded/capped" to around 10Mbps downstream despite your line is showing a "steady" (I let you to verify that if you're still suffering from random drop-outs/speed-decreases and SNR changes). If that is the case, with your ISP's agreement and yours, perhaps it is worthwhile to temporarily remove that cap completely and try again on your Test-Socket trials etc.
Just my thinking!!

And having at one time been stuck on 6655, I can confirm those bands. But, if the upper band is 14336, then I'm some way below that.

SPD.

Quite a lot has changed on WBC so there may be more bands now (that list was 2009)

Response from ISP.

"The lower sync speed on your extensions would likely be due to low
quality copper being used in the extensions when being built. These
extensions are considered outside of the BT network, and so would not be
considered a fault.

The sync speed into the test socket can be higher, but would be limited
by the amount of times you have been restarting your router. If you were
to leave it in a higher quality extension or the test socket, you would
likely see your sync speed increase further.

Also, sync speed is not set solely on line attenuation. There are many
other factors including length of line, signal to noise ratio,
disconnections, initialisations etc. Sync speed is decided by the BT
DSLAM based on all these factors and more."

SPD

Mostly a load of bull.

Extension wiring poor quality copper would reveal itself as an attenuation increase.
Externsion wiring not using twisted pair, or wrongly wired will cause slow speeds.

In short ISP is washing hands I think.

That leaves me to ask two questions.

1. Where would you suspect the problem to lie? Exchange? Somewhere between here and there?

2. Currently buying through an Enta reseller (although that support answer came from Enta directly). I've been tempted to switch to an LLU provider - would you recommend it?

Exchange = CMBRI.

TIA,

SPD.

EDIT: Well, blow me down with a feather. I've not rebooted the router for nearly 27 hours. It's connected to the fastest socket in the house outside of the test socket - in fact, I've even mounted it on the wall with rawl plugs, screws and all - and it currently sync'd at 13303. It's climbed 2000Kbps! Hmmm, downstream SNR has dropped though to 3.0.

Edited by deleted (Tue 14-Feb-12 19:24:45)

If the in property wiring is not an issue, then down to the configuration of your service in the big BT Wholesale cloud.

if you want to email telephone number, and copy of stats, can enquire of BT Wholesale if you are banded.

Andrew

Thanks Andrew, but I've edited my post as you were writing yours. Take a look.

SPD.