How to limit DSL connection speed on Thomson TG585 v7 router?

Question

I have ADSL via a Thomson TG585 v7 router (Demon Internet).

Generally these days its DSL connection reports something like

Bandwidth (Up/Down) [kbps/kbps]:  1.023 / 7.621

I'm interested in limiting the connection speed to a little slower: a year or so ago with the same router it used to connect at 4-6Mbit or so, and there was just less weirdness with e.g apt-get downloads suddenly slowing to a crawl or the router failing to establish an internet connection after restart without being prodded to retry via the web interface.

If I telnet into the box, the xdsl maxspeed command seems like it should let me inspect/control the maximum rate; but while (following a xdsl maxspeed tx=800000 rx=5000000, saveall and system reboot) I can get it to show:

XDSL Predefined Maximum speed: Upstream: 800000 Downstream: 5000000
XDSL Actual Maximum speed Upstream: 1023000 Downstream: 7736000

The predefined maximum speed seems not to actually have any effect on the connection established and the router's web interface also still reports the >7MBit/s DSL bandwidth. (Same even if I power cycle the router rather than soft-restarting it).

Any ideas if it's possible to limit the DSL speed on this router, and if so, how ?

NB I'm not just trying to limit bandwidth at the TCP/IP level. This is more to do with persuading the DSL connection negotiation to be more conservative about how much data it tries to cram down a noisy line.

Answer 1

Any need for this information went away after while, with the line quality apparently improving, or at least the router somehow figured out how to deal with it itself.