Assume the following information: Original timestamp value: 46 Receive…
2014
Assume the following information:
Original timestamp value: 46
Receive timestamp value: 59
Transmit timestamp value: 60
Timestamp at arrival of packet: 69
Which of the following statements is correct?
- A.
Receive clock should go back by 3 milliseconds
- B.
Transmit and Receive clocks are synchronized
- C.
Transmit clock should go back by 3 milliseconds
- D.
Receive clock should go ahead by 1 milliseconds
Attempted by 57 students.
Show answer & explanation
Correct answer: A
Given timestamps: T1 = 46, T2 = 59, T3 = 60, and T4 = 69.
Sending time: T2 - T1 = 59 - 46 = 13 ms
Receiving time: T4 - T3 = 69 - 60 = 9 ms
Round-trip time: 13 + 9 = 22 ms
One-way time: 22 / 2 = 11 ms
At the receiver-side reply point, the expected sender-side time is 46 + 11 = 57 ms. The receiver clock shows 60 ms, so it is ahead by 3 ms.
Correct answer: The receive clock should go back by 3 milliseconds.