Optimization of Computer Networks: Modeling and Algorithms presents a rigorous approach to the design and optimization of computer networks. Organized into two parts, it guides readers through the process of modeling network problems as optimization programs and applying optimization theory to gain insights into these challenges. Four key problem types—traffic routing, capacity dimensioning, congestion control, and topology design—are addressed systematically. The second part focuses on algorithm design for solving the network problems modeled in the first part, exploring both gradient-like algorithms that inspire distributed network protocols and cross-layer schemes coordinating protocol cooperation. It also covers heuristic algorithms for long-term static network design and planning. A hands-on approach is maintained throughout, with real-life examples from technologies like IP, wireless, and optical networks. Users will benefit from access to a comprehensive set of models and algorithms implemented in the open-source Net2Plan tool, enabling them to see practical applications and reuse or execute these solutions for numerical results.