ALAN: A (Circuit-Switched) Local Area Network

Our view is that people (that is, programmers and general computer users) tend to work together in small groups, where information and resources are shared freely within a group. Most interactions occur within the group (called a cluster)-sending messages, exchanging data, sharing a printer. Communication outside the cluster-sending mail to someone in another group or using a large number cruncher-is comparalively rare. Under this hypothesis, it is advantageous to optimize and simplify interactions within the group. This paper describes our attempt to design a cluster network based on a nonblocking crosspoint switch, which we call ALAN (a local area net). ALAN clusters are star-connected-with intelligent workstation nodes (PC's) at the points of the star, and the ALAN switch at the center.