Your diagram is certinly for a I-Plate. All Filter faceplates, be they from BT or anyone else, produce the ring line after the main line filter (in the case of BT and its varients, the capacitor is C8 on the main board, for ADSL Nation, it is C5).

As I have said, I will confirm how the VDSL plate deals with the ring line when I get a filter to look at.

Edited by deleted (Sun 22-May-11 06:06:57)