I had the pleasure of building telco networks with Marconi kit, lovely stuff. Nortel kit was rather good too.
Back to broadband discussion, the location of your router has the greatest influence on your speed. Ensure your primary socket has an I-Plate fitted as either part of the standard socket or as an after market upgrade. The in-built filters greatly reduce the arial effect from unshielded domestic wiring which kills BB speeds. Connect your router directly to this socket, nowhere else. One well respected Mod upped his speed from sub 1 Mb to 6 Mb in under 48 hrs after we moved the router.
The BT marketing has to keep pace with the promises made by the competition hence the user believes that if they don't get the full speed then there's a problem. The only real solutions are to sort out your internal wiring and electrical interference issues on wireless broadband while BT roll out Infinity which delivers BB over fibre to the street cabinet or to your house.
There's plenty of stuff on the web.
afterthought : if you have 6Mb today, what will you do with anything more ? Video on demand needs less than 2Mb (standard definition).