This course provides detailed knowledge of the design of equipment and protocols used to build communication networks such as the Internet. The course has five parts: 1. Switches: The motivations for switched networks, and the fabrics that provide the core switching function inside switches and routers. This includes time- and space-division switches, and all-optical switches. 2. Algorithms and techniques for implementing other functions of switches and routers, such as packet classification, buffering, and traffic management. 3. Protocols used between switches and routers, such as the Spanning Tree Protocol and bridges, signalling protocols, fast packet switching and tag switching. 4. Other internetworking devices, e.g. caches, load balancers, and layer 4/7 switches. 5. Design of networks in terms of dimensioning links and nodes (equipment) in order to achieve performance objectives.