Need help with GBN, ST, and TCP if someone could help as soon as possible 3. TCP
ID: 3913883 • Letter: N
Question
Need help with GBN, ST, and TCP if someone could help as soon as possible
3. TCP, GBN, and SR (20 points) Compare GBN, SR, and TCP (no delayed ACK). Assume that the timeout values for all three protocols are sufficiently long such that 4 consecutive data segments with sequence number 1, 2, 3, 4 can be received by the receiving host (Host B) and their corresponding ACKs can be received by the sending host (Host A). Suppose Host A sends data segments to Host B, and the first ACK (sent from Host B to Host A) is lost. In the end, all the 4 data segments have been correctly received by Host B. (no proof is required) a) If GBN is applied, how many data segments has Host A sent in total, and what are their sequence numbers respectively? How many ACKs has Host A received in total, and what are their sequence numbers respectively? (8 points) Answer b) IfSR is applied, how many segments has Host A sent in total, and what are their sequence numbers respectively? How many ACKs has Host B sent in total, and what are their sequence numbers respectively? (6 points) Answer c) If TCP is applied, how many segments has Host A sent in total, and what are their sequence numbers respectively? How many ACKs has Host A received in total, and what are their sequence numbers respectively? (6 points) AnswerExplanation / Answer
GBN:
A sends 8 segments in total. They are initially sent segments 1, 2, 3, 4 and later re-sent segments 1,2, 3, and 4.
B sends 4 ACKs in total aftter lossing the fisrt ACK. 4 ACKS with sequence numbers 1, 2, 3, and 4.
SR:
A sends 5 segments in total. They are initially sent segments 1, 2, 3, 4 and later re-sent segments 1.
B sends 4 ACKs. They are 3 ACKS with sequence number 2, 3, 4. And there is one ACK with sequence number 1.
TCP:
A sends 5 segments in total. They are initially sent segments 1, 2, 3, 4 and later re-sent segments 1.
B sends 5 ACKs. They are 3 ACKS with sequence number 1. There is one ACK withsequence numbers 5. Note that TCP always send an ACK with expected sequencenumber.