Transport, Switching, and Routing Technologies

This chapter elaborates on the main transport, switching, and routing smart grid‐related technologies. It also includes the main mechanisms that make packet‐switching technologies work. Transport function carries telecommunications information in a point‐to‐point manner, connecting network elements. The evolution of digital transport technologies has consolidated a group of technologies of different origins that both supersede and complement each other. Time division multiplexing digital data transport made use of the so‐called “Plesiochronous Digital Hierarchy” with different implementations worldwide. Switches are “smarter” devices than hubs, since they must look at the frame's destination address and forward it to the corresponding port, thus avoiding bottlenecks. The chapter sheds light on how the routing can be performed efficiently and how closed loops can be avoided by organizing the forwarding in a spanning tree shape. The successful and pervasive adoption of packet‐based technologies has led to their adaptation to be used in the transport technologies domain.