are you talking about vdsl2?
if 6dB target gives attainable just above sync
and 9dB target gives attainable way above sync
why does 3dB target give attainable just above sync.
A 9dB target SNRM should give an attainable just above sync (on fastpath). I've never seen a 9dB target though.
It's simple! The attainable changes in a similar pattern to sync when the target snrm is lowered, remaining just above sync. This is the case on 6dB, 5dB, 4dB and 3dB. The same would happen in the other direction, only lowering together rather than increasing. If the attainable ignored the actual target SNRM the above wouldn't happen.
Sometimes, just sometimes, what you assumed to be true is wrong, and someone comes along and points it out. Today that someone is me. I've made around 20 posts on here in the past couple months. 5 or 6 of those posts someone has wrongly tried to correct me. I've been right every time
I have no more to say on this matter. I'm peeing into the wind.