Towards a Universal Data Transport System

It is anticipated that a ubiquitous data transport system will require integration of local area and wide area networks. The combined network will need to present a uniform appearance to the user, be effective as a transport mechanism for a great variety of traffic patterns, and be economically appropriate for a wide range of consumer products. Learning from telephony and from experiments with a local area network, we conclude that the transport system must seek a clean separation of function and protocol between the network and its users. This separation is achieved by a byte-stream architecture that carries control and data bytes over switched virtual circuits. A DATAKIT packet switch demonstrates how the byte-stream concept can integrate local area and wide area network objectives. This switch is an assembly of interface modules connected by a pair of short passive buses. Each type of interface module serves one type of remote equipment and, if need be, terminates the protocol of that equipment. There are interface modules for trunks that lead to other packet switches, for terminals, and for host computers. Other modules provide system timing, switching, network control, and maintenance support.