@pippincp Possibly, possibly not. I am not sure if G.Inp being applied to a line is a pre-requisite for DLM setting a 3dB margin. I have yet to see any documentation clarifying one way or the other but suspect it could be. The only definite thing is they are separate mechanisms.
@licquorice Then riddle me this. If G.INP is not a pre-requisit, why don't you see any ECI cabs that don't support G.INP with a 3dB noise margin?
@pippincp They trialled 3dB margin on ECI cabs but it wasn't successful so it was abandoned. As far as I'm aware, the trial was independent of the G.Inp trials on ECI cabs.