Telephone Sockets
Non-NTE5
This socket could be an old style master socket, or it could be a secondary socket. Openreach should not be installing this style of socket as the master socket when installing a new phone line.
NTE5
This is the 'standard' socket that Openreach will install, it has been the standard since the 1980's. The lower half is removable. Removing the lower half gives access to the 'Test Socket' as well as the connectors