Researchers from the University of Massachusetts at Amherst and Dartmouth College jointly propose to perform fundamental research on developing a fluid simulation methodology that will enable efficient, multi-time-scale, hierarchical performance modeling of complex networks such as the next generation Internet. The proposed effort will allow networks to be more easily modeled and their performance to be evaluated significantly faster; it will make it possible to model significantly larger networks than before and to allow the tradeoffs between modeling accuracy and solution speed to be quantitatively assessed. The novel features of the proposed fluid modeling methodology include: > >Modeling at multiple time-scales. The proposed unified modeling framework provides for modeling system behavior at different time-scales, allowing for significant savings in simulation execution times when modeling at coarser time-scales. Development of formal means for quantitatively characterizing the potential loss of modeling accuracy when fast-time-scale behavior is modeled at a coarser time-scale is an important part of the framework. > >Hierarchical fluid modeling. The PIs demonstrate that multi-level (hierarchical) fluid modeling allows for abstraction of a potentially complex component of the simulation by a simpler model and substitution of this simpler model into the larger simulation. The PIs also develop rigorous techniques that can automatically identify when such substitution can be performed without significant loss of modeling accuracy. > >Efficiency in modeling complex systems. The PIs demonstrate that in addition to providing for multi-time-scale, multi-level modeling, fluid simulation can be significantly more efficient than traditional discrete event simulation. The PIs' initial work shows a 50-fold speedup in a uniprocessor fluid simulation speed over the discrete-event counterpart with little loss in modeling accuracy. > >Applicability in many problem domains. The PIs demonstrate that fluid simulation methodologies are ``plug and play'' in the sense that they can be applied equally well to the current Internet protocol suite, future real-time and multicast protocols, or ATM networks. >
