I am looking at the C trumpet articulations in particular though I imagine the answer is general to all instruments but what specifically is the legato sus?

I am hoping that I will be told it is an exact clone of the legato envelope with the appropriate section looped in such a way to simulate a mofo with elephant sized lungs but if so does it use the fast or regular attack and release (first and last parts of the envelope) or if not in what other way does it differ.

I appreciate knowing.

Thanks,

Brian