REIN, or R
oise to give it its full & fancy name is one of the biggest bug bears of broadband. In short this is interference on the telephone line that affects the broad band speed &/or stability. It can be caused by numerous things, from nearby transmitters to street lights & flashing Christmas lights!
The good news is there are a couple of devices that can be fitted to try & combat this. First off it the BT 80BRF3 :-https://www.run-it-direct.co.uk/bt-junction-boxes/BT80BRF3/
This small device is fitted upstream of the master socket, screw terminals connect to the incoming line & IDC terminals connect to the cable that feeds the master socket. The RF filter cuts out the radio interference which in turn improves broadband speed & stability.
The second device that can fix this problem is the BT VDSL faceplate :-https://www.run-it-direct.co.uk/adsl-faceplates/btvdslfaceplate/
This is a filtered faceplate that is compatible with ADSL & VDSL...