Sandia National Laboratories is using a set of evolving technologies to develop a standards-based approach to wide- and local-area networking, which offers the potential of gigabit speeds. In particular, asynchronous transfer mode (ATM) switches and synchronous optical network (SONET) technologies were used to build a supercomputing network between its California and New Mexico sites and now is being deployed in the local-area environment. The progress of these endeavors and the lessons learned are discussed.>

The newly installed terminal switching network at Sandia National Laboratories has been modeled with analytic and simulation techniques. Using classical queuing techniques and parameters derived from recorded usage data, fair and equitable allocations of interactive computer ports have been made. The allocations were then refined through the use of simulation techniques. The effect of balking as an alternative to entering queues has been shown to have substantial performance and stabilization effects on the network. In addition, it was found that the probability of balking as a function of queue length is not a monotonically increasing function. The simulation programs are also used to evaluate the performance of other interactive computer systems when subjected to various loads.