What is switching? It's a bit of an abbreviated term to describe the aspect of telecommunications that connects parties togther. A switch is the thing that gives you dial tone when you pick up your phone, and that makes your phone ring. My obsession with obsolete telecommunications has led me to drag home a number of pieces of equipment over the years.
My collection currently consists of three systems -- two Northern Telecom SG-1As (a 40 line unit and a 120 line unit), and Briths Ericsson 50 line PABX.