You may have spotted a problem in my plan. Rather than have the slave socket I was going to connect directly to he patch panel. So in essence that is a direct connection from the 2 wires the phone needs in the RJ11 to the patch panel,across to the phone bit of the patch panel and then back to the wired end in the master socket. Hence why I was thinking I need to know which pins/ colours the phone would use in the RJ11.

The flaw seems to be that I have forgotten about the broadband router's which also needs to be connected to the patch panel phone connectors. So need some way of splitting filtered Vs unfiltered. At the moment the phones are directly wired into the back of the slave socket and the router connected via one of those filter things in the faceplate. Having now said this it sounds a bit odd. It was something I quickly knocked together to get something working during building works

I assume phone is unfiltered and the modem and alarm are filtered?