Circuit-switching vs. packet-switching question:

Host A and host B are connected by switches X and Y as follows: A-X-Y-B. Links AX and YB each have a capacity of 20 Mbps, while link XY has a capacity of 30 Mbps. The propagation delay on each of the links is 10 ms. Calculate the time required to transfer a 10 MByte file from A to B under the two following scenarios:

(a) Circuit-switching is used. Assume that each link uses TDM (Time Division Multiplexing) and the link bandwidth is divided into frames such that each time slot corresponds to a capacity of 2 Mbps. Suppose that the connection setup time is 300 ms.

(b) Packet-switching is used and the file is transmitted using 5 KByte packets sent from host A to host B.