They are an important introductory material prepares the reader for further research and development in the field of performance modeling, analysis and engineering of heterogeneous networks and internets next and future generations. The chapters have been broadly classified into 12 sections covering the following topics: Measurement Techniques: Modeling and Traffic Engineering: Queuing Systems and Networks; Analytic Methodology, Engineering Simulation, Performance Evaluation Study: Mobile, Wireless and Ad Hoc Networks, Optical Networks: QoS Metrics and Algorithms; All IP and Network Convergence; Network Management and Services; and Overlay Network.