Cross Bar: The crossbar network is simplest interconnection network. It has a double dimensional grid of switches.  It's a Non-blocking network and offers connectivity between outputs and inputs as well as it's probable to combine any of the inputs to any output.

An N * M crossbar network is displayed in the subsequent Figure 1(a) and switch connections are displayed in Figure 1(b).

Figure: 1(a)

Figure: Crossbar Network

A switch located at the cross point of a specific row and specific column attaches that specific row (input) with column (output).

Hardware cost of N*N crossbar switch is proportional to N2. This creates delay equivalent to one switching operation and routing control mechanism is easy. Crossbar network necessitates N2 switches for N input and N output network.