How does a VCS Expressway solution work?

How does a VCS Expressway solution work?

A.
Packets sent through a firewall are tagged by the VCS Expressway and Control, so they can travel through any port

B.
The VCS Control and Expressway have manually configured IP address and ports that the
firewall has opened in both directions

C.
Packets from the VCS Expressway to the VCS Control are only sent on the return path of an outbound connection

D.
All incoming data sent through the VCS Expressway is delivered to the VCS Control through a single port