Consider an end system A connected to an end system B by four full-duplex links (same rates in the two directions but different output buffers) and three packet switches. Let di, Si, and Ri denote the length, propagation speed, and the transmission rate of link i, for i = 1, 2, 3, 4. Assume there is no other traffic on this network, negligible processing delays, and the output buffers are infinite. Assume the packets have a size of L bits (H bits size of header and P bits size of payload), and A has to send a file of size F bits to B. Provide the expressions in function of the given parameters to compute the following metrics and motivate your response. a) [5 pts] The end-to-end delay of the first packet sent from A to B? b) [5 pts] The end-to-end delay of receiving the whole file at B when R1