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Consider the transmission of a file of size F [byte] over a packet-switched network route consisting of three links (i.e., traversing two packet-switching routers). The links have transmission bit rates R1 = 16R [bit/s], R2 = 4R [bit/s], and R3 = R [bit/s]. Suppose propagation delays and processing delays are negligible and there are no other traffic flows traversing these three links. We employ a reliable transmission protocol with acknowledgements.

(a) Suppose the entire file is sent as one large message and one acknowledgement is sent for the entire file. What is the delay from the start of the transmission at the sender to the receipt of the acknowledgement at the sender?

(b) Suppose the file is partitioned into segments of size P [byte] with F P being an integer and an acknowledgement is sent for each segment. Suppose further that we employ a send-and-wait (stop-and-wait) reliable transport protocol, i.e., only one unacknowledged segment is allowed to be out in the network at any point in time. What is the delay from the start of the transmission at the sender to the receipt of the acknowledgement for the last segment at the sender?

(c) Consider the same segmented transmission as in part (b). However, now consider a pipelined reliable transport protocol with a window size of two segments, i.e., two unacknowledged segment are allowed to be out in the network at any point in time. What is the delay from the start of the transmission at the sender to the receipt of the acknowledgement for the last segment at the sender?