Network rendering.

We tried some network rendering with opengl … and recognized that we don’t know very much about that topic.
So, my question is:
What are the processes happening when a user starts a program from a remote machine that connects to a local display. We are using X that supports redirecting the display.
We were supposing that even if the remote machine does NOT support hardware rendering and the local one DOES, the rendering of the running program IS h/w accelerated. (Our first expierence proofed us wrong!).