Problem 9 Suppose Host A sends 6 consecutive segments to Host B. Suppose the 1st segment is lost (when transmitted for the first time) and there is no further loss. Suppose that the sequence number starts from 1 and increments by 1 per segment. Further suppose that under Go-Back-N (GBN) or Selective- Repeat (SR) protocol, the acknowledgement number is the sequence number of the segment it acknowledges (initially 0), and under TCP, the acknowledgement number is the sequence number of the next segment it expects. In the case of TCP, suppose that the sender uses fast retransmission, and the receiver buffers out-of-order segments. a) Under each of GBN, SR, and TCP: How many segments will Host A send in total? How many ACKS will Host B send in total? b) Give the sequence number of each segment sent by A, and the acknowledgement number of each ACK sent by B, under each protocol. c) Suppose that the timeout values of all three protocols are longer than the time to send 6 segments and receive their ACKs (if not lost). Which protocol delivers all the segments fastest? Why? Problem 9 Suppose Host A sends 6 consecutive segments to Host B. Suppose the 1st segment is lost (when transmitted for the first time) and there is no further loss. Suppose that the sequence number starts from 1 and increments by 1 per segment. Further suppose that under Go-Back-N (GBN) or Selective- Repeat (SR) protocol, the acknowledgement number is the sequence number of the segment it acknowledges (initially 0), and under TCP, the acknowledgement number is the sequence number of the next segment it expects. In the case of TCP, suppose that the sender uses fast retransmission, and the receiver buffers out-of-order segments. a) Under each of GBN, SR, and TCP: How many segments will Host A send in total? How many ACKS will Host B send in total? b) Give the sequence number of each segment sent by A, and the acknowledgement number of each ACK sent by B, under each protocol. c) Suppose that the timeout values of all three protocols are longer than the time to send 6 segments and receive their ACKs (if not lost). Which protocol delivers all the segments fastest? Why