How do you interconnect a large, heterogeneous group of computers, batch terminals and conversational terminals to form a general purpose network of computing resources? What techniques and technologies can be applied to maximize throughput and minimize response times? Is major surgery on host processor operating systems really necessary to interface to a communications network? This paper will describe a packet switching data communications network under development at the National Security Agency for resource sharing and the future development of distributed processing and filing systems. Starting with an experimental three node loop, the network will consist of a hierarchy of interconnected loops or rings probably based on Bell System T carrier digital transmission technology. Also discussed will be the means of nodal connection to the loops, the configuration of a node, network protocol, security considerations and implications for the future.