I gained about 1.5mbit/s (on a 3mbit/s line) by replacing all the copper in my house. A lot of people don't know this and continue to blame BT etc when it's their shoddy wiring that's causing problems not only in their house but sometimes extending to the roadside cab.
Originally Posted by Milo Minderbinder
the type of, and condition of, cable feeding your premises can make a major difference.
One local trading estate here is fed by an aluminium cable around 1.5km long from the nearest cabinet and the busineeses there are lucky if they get better than 0.5Mb. Total cable length is around 3.5km to the exchange (which should be OK), but the aluminium section simply carries too much noise.
However I got BT Infitiy installed at one of the companies last week and their speed went from 200kb/s to 15Mb/s. It looks - based on that one case - that the Infinity system may cope with aluminium better.
It's unlikely that aluminium is fed through the whole run, given that it's not been used in BT cabling for a long while. FTTC is only to the roadside cab, and then fibre from there to the exchange, but even the small run of aluminium to the cab would kill FTTC given the frequencies involved.