Users would dial into the terminal servers with a TCP/IP package, using a private network address (RFCxxxx specifies a number of class A, B and C addresses for which a route would never be published).
A private network address on the SLIP or PPP links would mean that people on those links would be unable to access the Internet directly. They would have to go through some kind of NCF "proxy server."
This setup eliminates two major components: the CPU servers, and the disk space servers. The rest of the components would remain the same.