wodWPN makes data transfer peer to peer or over a (General questions)

I have VNC client & VNC server applications written in Delphi7.
I will use my own mediator (with wodWPN).

I want to be sure that All the incoming and outgoing data will pass over the mediator or not.

I expect that after 2 side (client and server) connected to the mediator, a peer to peer connection will be established between them and the mediator's duty will finish.

Otherwise it is not logical to pass all the data over mediator.
I already can do this without using wodVPN.