Can someone please clarify the position with regard to the bell wire
in domestic telephone cabling.

Some web sources imply that it is no longer necessary with modern
phones. Other web sites show each extension connected with three wires
- the third being the bell wire.

I am about to install additional extension sockets - primarily to
allow connections for a Sky digibox and I want to get by on one pair,
if that will work.

Some sites suggest that getting rid of all the bell wires helps
improve one's broadband speed.

Just what is the truth?

Yvonne