Thanks for the response Bitn2. I have Fanvil X6, Fanvil X4U, Grandstream GRP2601P, Fanvil X1SP and FlyingVoice P23G. There's also a massive box of CISCO phones that I've put away since shutting down freepbx. I thought the X6 and X4 should be ok for router phones, but the install isn't seeing...