ABSTRACT
Computer networks were comprised of a single host with multiple terminals used for access. The topology used to connect these terminals to the central host was relatively simple. The most generic network topology classifications are centralized, decentralized and distributed. The centralized network, in which control functions are centralized, is the simplest of data communications arrangements where switching has been introduced into the network. Multiplexing comes in two basic forms, frequency-division multiplexing (FDM) and time-division multiplexing (TDM). A special system of TDM involves the use of a concentrator. Decentralized networks are little more than expanded centralized networks; that is, a decentralized network can be viewed as a network with nodes that have the added capability for switching between circuits. The distributed network, using packet-switching techniques, is generally considered to have the greatest potential for networks of the future because of the inherent reliability for continuity of operation.
