The course deals with the description and importance of the required hardware and selected protocols used for service and management of wired and wireless data networks. Following the hierarchical division of a network, switching nodes designed for individual hierarchical levels are described in more detail. The inner structure of the switch and router is described in more detail and also the operations performed on the data units are discussed. The issues of inner blocking, output port competition, queue blocking, multicast transfer, and cell selection algorithms are discussed. The key-properties of selected distance vector and link-state routing protocols are analyzed. Finally, the mechanisms ensuring quality of service in data networks and possible implementation of these mechanisms in switching nodes, and techniques ensuring the security and protection of the data network are also discussed.