Slow broadband - upload faster than download

Slow broadband - upload (0.26 Mbps) faster than download (0.70 Mbps)

Speed kbps Download 256 Upload 704
Noise margin dB Download 33 Upload 10
Attenuation dB Download 41.7 Upload 20

ISP wants to charge £50 to visit premises.
Speed is very similar from master socket test point.
Ring wires have been disconnected.
Cable from pole in street has a support point on another building where there is a junction box with a plastic cover which is not properly closed leaving terminals hanging out exposed to atmosphere.

To me it seems as though the speed could be increased as the noise margin os well above 6dB
Is my thinking correct?

Cool web home suggests we should be able to get 4800 minimum.

Your noise margin for download is wrong. They should be able to fix this remotely without any engineer visiting your premises. If a line is not running at the full available speed noise margin for downstream should be around 6dB normally, not 30dB.

Who is your ISP? What you really need to ask them is to reset the target noise margin.

Does the noise margin vary? And if so when and by how much? You could be getting moisture onto the joints if they are not sealed which might cause some problems although if they cannot track to earth or each other it will be less.

Get a copy of RouterStatsLight and leave it running for 48 hours to monitor the line and see what happens. But before that try the following.

Turn off power to the hub and wait 1 minute.
Disconnect the lead from socket to hub.
Leave everything OFF for an hour - yes, ISPs say three to five minutes, however from experience a longer period can help.
Power-up the hub and allow it to fully settle - say 5 minutes.
Reconnect the lead from hub to socket
Wait for 2 or three minutes
Reconnect devices.

Check stats.

Does the telephone work?

Thank you for the above ideas.
Yes phone works fine.
I plan to follow the above suggestions later this afternoon.

Could be that the BT Wholesale DLM has applied excessive banding on the connection. ISP can get this lifted if they want.

Followed MHC suggestions. Left router disconnected for 3 hours. Speeds exactly the same!
Makes me doubt if the Belkin F9J1102v2 router is updating.
Ran TB's speed tester.
Still very slow 0.2 download 0.5 upload

Tried to run RouterStats Lite but it does not list the Belkin model as an optionand I could not get anywhere with the any make option.

Will try phoning TalkTalk tomorrow

Talk to ISP about banding

Been on holiday and come back to find that after a long strtuggle via the ISP's forum they have reset the line and it is now 22 times faster!
Speed kbps Download 5610 Upload 540
Noise margin dB Download 7.5 Upload 10.5
Attenuation dB Download 40.1 Upload 22.8

Noise margin seems slightly high, but I'm not going to continue to struggle to get a mnor improvement.

Thank you to all for your help.