1. Connect a phone cable between the Local Phone socket on the ADSL Filter and the black PSTN socket on the gateway. 2. Connect a phone cable between the ADSL modem socket on the ADSL Filter and the grey DSL socket on the gateway. 3. Connect a phone cable between the wall socket on the ADSL Filter and the wall outlet, as shown below. First, you'll need to check your type of master socket. This is the main telephone socket where the phone line enters your home (usually found in the hallway near the front door). Click on a link or picture. My master socket has one socket > My master socket has two sockets > Was this answer helpful? Print these instructions Need more help?. This guide will show you how to wire your extensions from an NTE5 type master socket using Cat5e/6 cable. If you have LJU type master socket and wish to use an NTE5 ADSL face plate, you are not out of luck! The NTE5 can be installed legally by the user. (Or contact BT and they will fit one for around £30).