3-stage switch; see need for k=2n-1 for it to be non-blocking A sends to C; B sends to D; C sends to A; D sends toB See that there is no blocking even if k=2 last updated March 8, 04 M. Veeraraghavan

3-stage switch; see need for k=2n-1 for it to be non-blocking A sends to C; B sends to F; E sends to A; Say F wants to send to E – it cannot use the first switch in the intermediate stage because of E to A connection, it cannot use the second switch because the B to F connection has used up the line to the third switch in the output stage. Hence we need the third intermediate switch last updated March 8, 04 M. Veeraraghavan