Mystery Problem...

At least it has BT Openreach and Sky beaten.....

I am barely1km from my local exchange on Sky LLU.
This is the actual distance by cable length.

4 weeks ago my Broadband stopped, with no synch.

After many weeks and much line checking and some new splices we now have Broadband, but despite the line being "clean" ( B.T comment) my stats are as follows:-

ADSL Link Downstream Upstream
Connection Speed 16027 kbps 765 kbps
Line Attenuation 21 db 8 db
Noise Margin 7 db 15 db

THe line attenuation on ADSL2 is only 21db, but the noise margin is only 7db at best.

Even on ADSL 1 I can only achieve 6440 download connect...
The line attenuation drops to 16db but I cannot achieve the full 8128 connect.

I have a filtered faceplate on my master socket.

BT Openreach have been out 3 times to my home, and can find no problems with the wiring inside or out to the pole. The drop cable was also replaced.

Any ideas why the maximum attainable synch is lower than I should be achieving?

The BT engineer has confirmed I am not on anything other than copper as far as he can tell.

One BT engineer did achieve just over 17mb with his router though.

5 netgear DG 934s have been tested to rule out a router problem.

Everyone is baffled.

Any thoughts anyone?

Edited by tempus (Thu 01-Apr-10 22:18:04)

Maybe you're too close to the exchange

I said 1 km not 1 meter!

In reply to a post by tempus:

At least it has BT Openreach and Sky beaten.....

I am barely1km from my local exchange on Sky LLU.
This is the actual distance by cable length.

4 weeks ago my Broadband stopped, with no synch.

After many weeks and much line checking and some new splices we now have Broadband, but despite the line being "clean" ( B.T comment) my stats are as follows:-

ADSL Link Downstream Upstream
Connection Speed 16027 kbps 765 kbps
Line Attenuation 21 db 8 db
Noise Margin 7 db 15 db

THe line attenuation on ADSL2 is only 21db, but the noise margin is only 7db at best.

16Mb. What's the problem?

Err...try re-reading it, maybe?

I didn't want fatuous replies, but maybe some intelligent reasoning as to why a line of this quality can't achieve what it should?

Otherwise, buying a car that is capable of 100mph which can only achieve 65mph would merit the same throw away response as yours....

THe line attenuation on ADSL2 is only 21db, but the noise margin is only 7db at best

What do you expect the noise margin to be and why?

In reply to a post by Apprentice:

THe line attenuation on ADSL2 is only 21db, but the noise margin is only 7db at best

What do you expect the noise margin to be and why?

It's more a case of what SKY and BT expect.

Obviously the line attenuation suggests the line is capable of more.
It is in reasonable condition, and is copper without any large chunks of aluminium, if any, en route.

The line should easily manage either 20mb on ADSL2, or very close anyway.
On g.dmt it should easily achieve 8mb.

It does neither.

The router is a netgear 934, and it is looking likely from some other forum postings that Sky may have compatibility problems with their own eqipment (lucent) and some netgears.

I have not yet been able to hear other people's experiences , particularly those on Sky Voice and Broadband, maybe those using the Sagem or even other makes?

So I am hoping for lucid, cogent experiences or possible explanations of what may be happening.

What was your sync rate and noise margin prior to your problems a few weeks back?

Downstream Upstream

16909 1139

Line Attenuation 20db 7db

Noise Margin 10db 8db

I suggest you beg, borrow, or steal some other makes and models of modems and see how they fare.