Advances in Performance Evaluation of Computer and Telecommunication Systems

Welcome to this special issue of Simulation: Transactions of the Society for Modeling and Simulation International on “Advances in Performance Evaluation of Computer and Telecommunication Systems.” The papers included in this special issue are based on selected extended versions of the best papers accepted in the 2006 International Symposium on Performance Evaluation of Computer and Telecommunication Systems, SPECTS 2006. We only accepted five papers in this special issue out of many selected extended versions of papers accepted in SPECTS 2006. This means that these accepted papers have undergone a thorough and critical review process by experts in the field. Martin and Westall present the design and elements of the validation of an ‘ns’ Data Over Cable Service Interface Specification (DOCSIS) simulation model. They derive an analytic model to validate the simulation model with respect to their understanding of the essential elements of the DOCSIS protocol. Further evidence that the simulation model is a valid representation of these elements of the protocol is obtained by running selected benchmark workloads on both the simulator and on operational DOCSIS networks. DOCSIS is a large and complex protocol and it is clear that there are other aspects of the simulation model that are yet to be validated. In the next phase of their work, the authors plan to use the testbed to show that the simulation model’s collision and recovery mechanisms work correctly in the presence of competing upstream traffic sources. The methods that they use for model validation, particularly the analysis of live networks, help to link the simulation model to real systems. Such a validated simulation model can be useful to the