This proposal defines a program of research, experimentation, technology development, and demonstrations leading to the creation of a national scale data communications network with transmission speeds in excess of a gigabit per second (1 Gb/s). Specific products of the overall project are the development and demonstration of long-haul networking at speeds greater than 100 megabits per second, and specification of the additional architectural development including protocols, switching fabrics, and fiber-optic transmission facilities for the gigabit network. This proposal may be thought of as the first phase of a multi-phase plan extending over several years. During this first phase the Corporation for National Research Initiatives (CNRI) will issue a call for white papers, evaluate the responses, hold numerous working group meetings, and working with the subcontractors develop/select an architectural approach for a very high speed network. The approach involves CNRI coordinating the efforts of industrial and academic participants, with very substantial cost-sharing by the private sector. At the end of this phase a detailed proposal will be produced along with a set of specific subcontrator tasks to be accomplished.