Openreach; and it's solid.

Are we talking about the cable between the router and master? If so it's about 3 to 5m of ISP supplied goodness. Far too long and is being replaced with a 1m cable on order.

it's ok. I'm just re-reading the info you've already posted and I think you've answered all my questions already.

Is that rust in the back box? If so, I would be more concerned about damp in the wall than the connection.

Don�t be touching them crimps, there�s not enough wire inside to play with.

To be honest, I think the wiring is fine and you're just being affected by aluminium cables as already stated.

The best way forward in my opinion it to use a modem that supports DSLstats and get some graphs on MyDslWebStats for analysis.

Reasonably common, damp tracking back up the exterior of the direct in ground cable. Not a good way to install cables, and that�s why they stopped it.

Update; my 1m RJ45 to RJ11 lead has arrived. It's made with BT CW1724 cable and has improved attenuation and max sync speed slightly.

Maximum data rate:
24817 / 62028
Noise margin:
8.9 / 6.2
Line attenuation:
15.2

If I ever get a separate modem in the future I will be sure to get the stats checked out for Ali.