On Jan 24, 11:15 am, Newps wrote:

There is always a fixed boundary, laterally and vertically. One thing
you can be sure of with ATC is that only one controller owns the
airspace at a time.

Oops, I do recall now seeing an overlay on Flight Tracker that showed
the Center boundaries.


Here in CT, once you climb past 15k or so you get handed off to Center.

The handoff occurred much earlier and means that the controller working
you now can let you enter the next controllers airspace.

What I meant by handoff was a frequency change. Whatever happens behind
the scenes is transparent to me