[BBKing]

Except that there isn't really an exchange as such, at least in a telephone sense. It's more correct to say that you and your local area connect via a mixture of coaxial (copper) and optical (glass fibre) to a central point known as a head-end, where your signals are translated into standard Ethernet IP packets and sent up a conventional internet.

So you don't have a dedicated connection per-se, you have a share in the network serving your area.

ADSL differs in that you have your own connection to the local exchange (up a standard copper pair telephone line) at which point clever machinery splits off the broadband signal and sends it up a conventional internet connection (along with a number of other people in your area, but not necessarily your immediate neighbours.