How does pulseaudio implement the zero-copy feature?

[fpemud]

The architecture of pulseaudio has both the feature of network transparency and zero-copy.
Comparing the arch of xcb in X, I think the arch should be very complicate.

I read some doc, what I get is when pulseaudio server and client is on one single machine, it transfers only the memory handle, so it's zerocopy.
Is there any doc describe more details?

And I have more interested in: will Wayland have the same two features? will wayland use the same arch?