You can check your echange for supplier equipment here:
http://www.samknows.com/broadband/exchange_search
What is Local Loop Unbundling (LLU)?
Local Loop Unbundling is the process by which third party network operators are able to install equipment in to BT telephone exchanges in order to provide their own services without having to touch BT’s network. Only the copper pair from the exchange to the premises, which remains the property of BT, is used by the third party.
There is a guy at work who moaned about crippling speeds for months, spent hours on the phone to BT, downloaded dozens of anti-spyware programs, formatted his hardrive etc before calling out a PC repair woman who unplugged his router for ten mins and fixed the problem. Heh.