I am confident that the household pre existing cabling with the 4 wires, orange, blue and white and multiples of, was BT cabling and installed and working some time ago - the extension cable I bought off Amazon probably would work on the basis that the cables went from pin 1 to output 1 thus just an extension cable - but my issue is joining the pre existing cable to the main socket!
Would be easier if I could show pictures I think, but I have 4 cables in the house that I need to put some kind of extension too as they are too short to reach the BT main socket...but there are only two cables coming into the box that are used..... orange and white..... I think I may just give in gracefully.....
Problem with alarm cabling is it’s usually untwisted pairs, which can easily allow unwanted noise in, which in turn could cause errors and ultimately drops in your connection.