Issue No. 11 - November (1977 vol. 10)
S.K. Jones , Texas A&M University
Communication networks for digital data transmission can be classified as either circuit switched, message switched, or packet switched. In circuit-switched networks, a direct communication link is established between two users by closing a sequence of switches at appropriate network node points. The message is then transmitted continuously as is done, for example, in the national telephone network. In a message-switched network, the complete message is routed from node to node in the network until it reaches its destination. At each node, the message is placed in a queue to await next-node routing decisions and retransmission to a neighboring mode. Because of this two-step process, message-switched networks are known as store-and- forward networks. The packet-switched network is also a member of the store-and-forward class and differs from the message-switched network in that each message is subdivided into basic units called packets before being offered as input to the network.
R. Cavin and S. Jones, "Dynamic Modeling and Control of Digital Communication Networks," in Computer, vol. 10, no. , pp. 60-64, 1977.