Q. Show Organisation of Clos network?

Clos network: This network was designed by Clos (1953).  It's a non-blocking network and offers full connectivity similar to crossbar network however it needs majorly less number of switches. The structure of Clos network is displayed in Figure:

Figure: Organisation of Clos network

Think about an I input and O output network.

Number N is selected such that (I= n.x) and (O=p.y).

In Clos network input phase will comprise X switches each one having n input lines and z output lines. The final stage would comprise Y switches each having m input lines and p output lines and the middle phase will comprise z crossbar switches, each one of size X × Y. To make use of all inputs the value of Z is kept equal to or greater than n and p.