The test port contained in new master sockets by passes your internal wiring totally and is connecting to the BT line coming straight into the house. This is the point at which BT provide the ADSL service to as they are not responsible for your internal wiring.
If you have a issue with your broadband you really should test from the test port inside the master socket before calling your ISP as if they book an appointment for BT to visit and it is found to be your internal wiring then your ISP will be charged for the visit which is currently $144 + VAT and they may well pass this cost on to you.