SNR, Distance and Line Speed

I have an 'up to 8mbit' service from plusnet (recently transferred from madasafish).

Background Info:

I'm a fair way from my local exchange, SamKnows states 3.08km straight line distance

My router (Netgear DG834G v3) stats are as follows:

               ADSL Link                  Downstream    Upstream

               Connection Speed           2112 kbps     448 kbps

               Line Attenuation           55 db         15.5 db

               Noise Margin               7 db          20 db

If it's in the right mood my line will sync at around 2900kbps but will never hold it for more than a few hours and drops to sometimes as low as 1900 but usually 2100

I've tried several different routers (2Wire 2700HGV, Speedtouch 585 v6, Linksys Wag354G v1, D-Link DSL-G624T, D-Link DSL-2640B) and the results with the first two are similar to the Netgear, with the others slightly worse

All of my house phone wiring is separated from the broadband by an ADSL faceplate

Question:
If I look at ADSL speed graphs such as this one I get the feeling that my line ought to be doing somewhat better than it does, particularly from a SNR perspective. Before I challenge the performance with plusnet, does anyone feel that this is likely to be something 'fixable' or am I just wasting my time because: the line is too long, rubbish quality, BT Open Reach won't give a *****, etc, etc?

Any help gratefully received.

Despite using an ADSL faceplate if you connect to the test socket are the results any different.
The reason for asking is that the downstream attenuation seems high compared to the upstream value

Those figure are almost identical to mine and I get pretty much the same speeds (The margins don't look unusual either to me). I was getting an unreliable 2500ish on ADSL Max but on PN LLU I've settled for 2000 -> 2200 on 9dB margin and it's stable.

I have been trying to improve my speeds for years and no amount of faceplates, ring wire cutting or re-wiring has made any difference.

You will just have to face the fact that you are on a long, low quality line and you are getting as good a speed as is possible for your line conditions and ADSL technology. Even moving to ADSL2 may not give you any improvement due to distance.

Oldjim,

Connecting to the master/test socket makes no discernible difference.

in which case you just have a noisy line - so are probably stuck with it

Fairy nuff.

Thanks for the views.