A Clos network topology (diagrammed below) is parameterized by three integers n, m, and r: n represents the number of sources which feed into each of r ingress stage crossbar switches; each ingress stage crossbar switch has m outlets; and there are m middle stage crossbar switches.

Circuit switching arranges a dedicated communications path for a connection between endpoints for the duration of the connection. This sacrifices total bandwidth available if the dedicated connections are poorly utilized, but makes the connection and