TCP/IP to the Rescue
In 1973, work began on the TCP/IP protocol suite, a software-based set of networking protocols that allowed any system to connect to any other system, using any network topology. By 1978, IP version 4 (the same version that we use today) had been completed, although it would be another four years before the transition away from ARPAnet to IP would begin. Shortly thereafter, the University of California at Berkeley also began bundling TCP/IP with their freely distributed version of Unix, which was a widely used operating system in the research community.
The introduction and wide-scale deployment of TCP/IP represented a major ground-shift in computer networking. Until the introduction of TCP/IP, almost every other network topology required that hardware-based network nodes send traffic to a central host for processing, with the central host delivering the data to the destination node on behalf of the sender. For example, Figure 1.1 shows a host-centric networking architecture. In this model, devices are attached to a centralized system that coordinates all network traffic. A user at a terminal could not even send a screen of text to a printer without first sending the data to the central host, which would parse the data and eventually send it to the printer for printing.
But with TCP/IP, each network device was treated as a fully ...