Host A sends a packet of 72 bytes to host B via two routers. The distance between host A and the first router is 20 m. The distance between host B and the second router is 25 m. The distance between the two routers is 500 m. The propagation speed is 2 x 108m/sec. The recommended transmission rates are 10 Mbps between host A and the first router and 100 Mbps between the second router and host B. Each router spends 1.2 msec to perform error detection. If there is no congestion in the network, the recommended end-to-end delay for host A to send the packet to host B should not be longer than 3 msec.

(a)At what time the last bit of the packet leaves host A?

(b)At what time the last bit of the packet reaches the first router?

(c)At what time the first bit of the packet reaches the second router?

(d)Show your analysis and suggest the physical medium for the link between the two routers.