ABSTRACT
During the last decade, there has been a shift in the network marketing approach of data processing companies. In the 1970s, such a company would ensure that its customers would be able to communicate with one another within the company’s network facilities. The marketing argument was to provide the customer with equipment that would permit access to a very reliable, high performance, expandable network. This led to the creation of various heterogeneous commercial networks such as IBM’s SNA, DEC’s DECnet, or the Advanced Research Project Agency’s Network known as ARPANET. Different network design decisions generated heterogeneity among these systems and prevented them from collaborating. The end user of a given network was unable to communicate with any kind of end user in another given network.
