Networking has become an integral part of the work of DOE principal investigators, and this document is intended to assist the Office of Scientific Computing in ESnet program planning and management, including prioritization and funding. In particular, we identify the new directions that ESnet's development and implementation will take over the course of the next several years. Our basic goal is to ensure that the networking requirements of the respective scientific programs within Energy Research are addressed fairly. However, it should be kept in mind that while ESnet's basic mission is to support OER-funded research, other DOE offices are now participating in ESnet and sharing ESnet resources. These and other similarly evolving relationships are only in their infancy; planning efforts for their further development are being initiated as this Program Plan goes to press.

This ESnet Program Plan is the third document of its kind. It was generated through the efforts of the ESnet Steering Committee and those of our associated researchers, managers, visionaries, and development and maintenance personnel. During the last few years, we have benefited from the vision and the implementation efforts of network experts both within the ER community and beyond. As the network has become increasingly transparent to users of more traditional computing tools, the advantages of networking have become highly visible and useful to those who create and reference essential scientific and administrative information and make it available to the ER community.

The proliferation of regional networks and additional network-related initiatives by other Federal agencies is changing the process by which we plan our own efforts to serve the DOE community. ESnet provides the Energy Research community with access to many other peer-level networks and to a multitude of other interconnected network facilities. ESnet's connectivity and relationship to these other networks and facilities are also described in this document.

Major Office of Energy Research programs are managed and coordinated by the Office of Basic Energy Sciences (OBES), the Office of High Energy and Nuclear Physics, the Office of Magnetic Fusion Energy, the Office of Scientific Computing, and the Office of Health and Environmental Research (OHER). Summaries of these programs are presented, along with their functional and technical requirements for wide-area networking. Changes in the ways these scientific programs use computing and information facilities have generally resulted in rapidly increasing networking needs. A major section of this Program Plan surveys current and future network utilization as projected by the Energy Research scientific community.

Forecasting networking demand is as much an art as a science. First of all, the measurement and analysis of current network utilization provides an important benchmark for estimating needed network growth. Second, many current end-user applications require bandwidth or connectivity that does not yet exist. Surveys of network users can help unearth such requirements. Third, advances in network-based applications and tools can generate less predictable accelerations in network utilization. For example, in this past year, we have benefited from the deployment of two new "killer" applications, videoconferencing and the network services related to Mosaic and the World Wide Web (WWW). These "killer" applications are so termed because their utility for and popularity with our scientific and information-based user community is generating increases in demand that will seriously stress the network unless bandwidth is increased quickly and dramatically.

The ESSC and its associates have long been active in generating and supporting Federal initiatives that pertain to networking. We are already benefiting from the early implementation of the Federal High Performance Computing and Communications Program and, in particular, its National Research and Educational Network component. We also hail the National Information Infrastructure as a vision that will further focus national attention on the critical role that networking must play in enhancing America's scientific and industrial competitiveness and in changing the way in which we work.