I’m just looking at couplers and RJ11 isn’t easy to find. However, an RJ11 cable will fit into an RJ45 socket and there are loads of RJ45 coupler options so I think I know which way I’ll go!
Cut the plugs off and solder the connections. . . 
I’m just looking at couplers and RJ11 isn’t easy to find. However, an RJ11 cable will fit into an RJ45 socket and there are loads of RJ45 coupler options so I think I know which way I’ll go!
Cut the plugs off and solder the connections. . .