Backplane bandwidth, or switching bandwidth, is the maximum data throughput that can occur between a switch's interface processor or card and its data bus. Represented in gigabits per second (Gbps), this parameter determines the total data exchange capacity of a switch. To ensure sufficient bandwidth, the requirement of backplane bandwidth to a 16-port Gigabit switch is (16*1000M*2)/1000=32Gbps. Step 3, confirm the packet forwarding. A backplane is a large printed circuit board that provides high-speed electrical interconnection and power distribution between multiple plug-in cards inside a chassis.