Advanced
Computer Networks
Q91 / 100
What is the difference between TCP SACK and selective retransmission?
Correct! Well done.
Incorrect.
The correct answer is B) SACK (Selective Acknowledgment) allows receivers to inform senders exactly which segments arrived, enabling selective retransmission of only lost segments rather than all following segments
B
Correct Answer
SACK (Selective Acknowledgment) allows receivers to inform senders exactly which segments arrived, enabling selective retransmission of only lost segments rather than all following segments
Explanation
Without SACK, TCP uses go-back-N (retransmit from loss point). With SACK (RFC 2018), the receiver reports gaps in received data. The sender retransmits only the missing segments, dramatically improving throughput on lossy links.
Progress
91/100