2. (6 marks) Two packets arrive at two different input ports on a router at the same time. a) Assuming the packets are destined for two different output ports, can they pass through the switch fabric at the same time using a crossbar? b) Assuming the packets are destined for two different output ports, can they pass through the switch fabric at the same time using a shared bus? c) Assuming the packets are destined for the same output port, can they pass through the switch fabric at the same time using a crossbar