On making the edit to my previous post (so as to attach the three images), it does seem as if there are
three white cables visible in
058_opt.jpg.
One would be the incoming service feed which originates at
059_opt.jpg, the second and third to run to the other two sockets. I've just re-read --
Our property only had 2 sockets, the first one in the hallway and another in the lounge by the tv aerial for Sky (unused). When BT visited to do whatever they have to do when you pay out £124.99 + for the connection, the technician gave OH a socket to fit himself (he's an electrician) to provide a further socket for the Broadband in another room.
You now have
three sockets. The one in the hallway (
058_opt.jpg), the one "
in the lounge by the tv aerial for Sky (unused)" and the one "
for the Broadband in another room", fitted by your electrician OH.
I now understand what has happened -- if there are, indeed, three cables that I see in
058_opt.jpg. You OH has wired up the third socket, from the
first, such that the pre-existing
second socket is acting as a
bridged-tap. Although what he has done is perfectly logical for electricity supply circuits and for telephones, it is not the correct method to use on a telephone circuit that will also carry a broadband service. Oops!
I would really like to see another couple of pictures of the hall socket. One that clearly shows which colour wire, from which cable, is connected to which IDC and a second one that shows the cables in the backing box within the wall.
For good measure, ditto the one "
in the lounge by the tv aerial for Sky (unused)" and ditto the one "
for the Broadband in another room".