Optimize Line Speed?

[#1]

Hi,
According to Plusnet staff on a previous ticket I am suffering high contention at my exchange when speeds deteriorate to well under 2Mbps. I have been monitoring my download speeds in the early afternoon when contention should be lower and achieving around 5Mbps. However, the BT Wholesale Performance Test further diagnostic element has not worked for the past few days, I'm on Firefox but have tried IE and another PC. The speed test works OK but the diagnostic element gives the message: ‘The Performance Tester is currently unable to run a speed test for your broadband connection. Please try again shortly, however if this problem persists, raise the issue with your service provider’. I therefore cannot see my IP Profile etc, although Plusnet shows my line speed today as 6Mb.
I think I should be getting better download speeds overall, I'm very near the exchange and I have an Openreach Mk2 Interstitial Faceplate. My (elderly) Belkin Router ADSL stats today are:
Data rate (Kbps): 7840 Downstream, 448 Upstream.
Noise Margin: 12 Downstream, 27 Upstream.
Output Power (dBm): 25 Downstream, 0 Upstream.
Attenuation (dB): 5 Downstream, 0 Upstream.
Any comments gratefully received

[#2]

Would it be correct to assume that your exchange isn't 21CN enabled - you can check here http://usertools.plus.net/exchanges/

[#3]

Your profile was a little lower than it should be. Please re-start your connection, you should be getting nearer to 6.5mbit throughput when all is working well.

[#4]

oldjm:
Sorry, I should have said It was 20CN. It has just been fibre enabled though, so I am considering this.

Plusnettony:
Thanks for the tweak. Speed has increased to just above 6 just now but we are moving to a high contention period, so I will monitor and report back. The BTW Diagnostic Test element is still not working on my PCs.

[#5]

Personally, I'd go for the fibre rather than waiting around for the VP changes (this is a 'technical' answer not 'sales' one).