It was a failure, it didn't look as if the conexter cut through the wire covering so back to the drawing board. The "old" screw" conextions were much more forgiving of this diffrences.

I suspected the cable may not be suitable.

Personally I would buy some Cat5e cable and a RJ11 socket. Run the cable from the data connections on the BT socket through the wall and then connected into the back of the RJ11 socket. Then you can plug a standard modem cable into the socket.

EDIT : You should also be able to use a standard RJ45 socket - RJ11 plugs will fit in RJ45 sockets - it may be easier/cheaper for RJ45 than for RJ11.

Edited by ian72 (Wed 05-Aug-20 11:25:48)

In reply to a post by ian72:

I suspected the cable may not be suitable.

Personally I would buy some Cat5e cable and a RJ11 socket. Run the cable from the data connections on the BT socket through the wall and then connected into the back of the RJ11 socket. Then you can plug a standard modem cable into the socket.

EDIT : You should also be able to use a standard RJ45 socket - RJ11 plugs will fit in RJ45 sockets - it may be easier/cheaper for RJ45 than for RJ11.

And the OP should make sure it is INFRASTRUCTURE Cat5e with solid conductors rather than multi-strand.

After the cable I tried failed to work in the BT conexter I am worried I may have the same problem with Cat5 as well

As another poster said as long as you use infrastructure cabling it should be fine - the RJ11 lead will not have suitable cable types for connecting.

Cat5e SOLID will be fine, you can get four pair or two pair, either will be suitable.

Cat5e 24 AWG has a conductor diameter of 0.5104 and BT internal CW1308 is 0.50 (nominal).

CAT5 cable will be fine.

Only thing to watch is that it is like some Telephone cable that I have come across which was on a drum marked "CCS" turned out to be Copper Covered Steel. Not good. Test with a magnet, proper CAT5 being copper will not be attracted by a magnet.

BT would use CW1308 cable. https://www.ebay.co.uk/itm/5M-WHITE-TELEPHONE-CABLE-... This seller is offering copper cable, but a quick search produced CCS which is not so good.

My advise to get a connection through a wall, is to use a RJ11 socket. Something like:
https://www.ebay.co.uk/itm/RJ11-TELEPHONE-SOCKET-MOD...

And a RJ to RJ cable of whatever length you need between that new socket and the MODEM.

Cheers!