The Kiewit network: a large AppleTalk internetwork

Dartmouth College's Kiewit Network connects nearly all of the computing resources on the campus: mainframes, minicomputers, personal computers, terminals, printers, and file servers. It is a large internetwork, based on the AppleTalk protocols. There are currently over 2900 AppleTalk outlets in 44 zones on campus. Over 90 minicomputers act as bridges between 177 AppleTalk twisted pair busses. This paper describes the extent and facilities of the current network; the extensions made to the AppleTalk protocols, including a stream protocol and an asynchronous link protocol; and current development projects, including an AppleTalk stream to TCP converter.

The Kiewit Network is a general purpose local data network. It serves as glue between all the host computers and nearly all the personal computers and terminals on campus. The network extends to the academic and administrative buildings, and the student residence halls, with network ports placed in almost all the offices and rooms. From these ports, users may access any of the host computers connected to the network. In addition, the hosts use network connections to communicate between themselves for electronic mail, file transfer, printer sharing, etc. The network also supports Apple Computer's AppleTalk® protocols. Departments and individuals can purchase standard devices which use AppleTalk (such as LaserWriters® and file servers), and connect them directly to the network.

The Kiewit Network is not part of the telephone, energy control, or security systems of the College. While there can be benefits from combining them, separating these systems has simplified our design in many ways. A network failure doesn't interrupt these other services. We can also schedule experimental time for testing new software at our convenience.

Dartmouth College started its campus network with General Electric Datanet 30 computers acting as front ends for the Dartmouth College Time Sharing (DCTS) system. In 1978, as the requirement for portsgrew, Honeywell 716 minicomputers replaced the Datanet machines. In the same time period, two factors forced a change in perspective away from a front-end function toward a networked approach. New hosts began to arrive on campus. These new machines required enhancements to the network. Second, off-campus sites demanded more ports than the existing phone lines could supply. We served these remote users by using Prime P200 minicomputers as statistical multiplexors. In 1980, we implemented the DCTS terminal handling protocols on a less expensive minicomputer, and began to place these network nodes in the basements of buildings across the campus.

When the College recommended that the freshmen entering in the fall of 1984 purchase a Macintosh#8482; computer, funds were appropriated for three major network enhancements: installation of a network port for each undergraduate in the residence halls; conversion of the network to the AppleTalk protocols; and creation of a terminal emulation program to exploit the enhanced network capabilities.