I've been looking at the Ethernet cable run and I'm sure its all away from the electric etc, done properly. But... the Master socket is now under the stair alongside the electric consumer unit. Its within 10 cms. Right above where the main power tails enter and where the main trip switch is located. And its also next to a double socket powering the router and a bunch of other stuff.
Could I be causing electrical interference to the xDSL line by having the Master here? In which case moving it back to the living room would be a sensible plan?