"GhostNode" - support relays that cannot accept incoming connections.
My ISP doesn't offer global IP address(10.10.20.X shared), which I can't help people by setting up middle(nonexit) nodes. Why tor require opening a port!?
What about HiddenService? It can work without opening a port to global, right? So, how about this idea.
"GhostNode" 1. It doesn't require user to open a port to global(no router setting). 2. It works like a hidden service protocol. Your global IP won't go public.
Client---torBridgeNode===tor2===tor2===tor4-->website or Client---tor1===tor2===tor4-->website
tor1; nonexit tor2; ghost tor4; exit
tor1 ask tor2 to connect tor4. (just like HiddenService did) tor2(GhostNode) make a connection to tor4(exitnode).