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Suppose two hosts use a TCP connection to transfer a large file. Which of the following statements is/are FALSE with respect to the TCP connection?
I. If the sequence number of a segment is m, then the sequence number of the subsequent segment is always m + 1.
II. If the estimated round trip time at any given point of time is t sec the value of the retransmission timeout is always set to greater than or equal to t sec.
III. The size of the advertised window never changes during the curse of the TCP connection.
IV. The number of unacknowledged bytes at the sender is always less than or equal to the advertised window.
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- III only
- I and III only
- I and IV only
- II and IV only
- III only
Correct Option: B
I : FALSE
The sequence number of the subsequent segment depends on the number of 8-byte characters in the current segment.
II : TRUE
Depending on the value of a or expected RTT it may or may not be greater than 1.
III : FALSE
It is the size of the receiver's buffer that's never changed. Receive Window is the part of the receiver's buffer that's changing all the time depending on the processing ability at the receiver's side and the network traffic.
IV : TRUE
The number of unappreciated bytes that A sends cannot exceed the size of the receiver's window. But if it can't exceed the receiver's window, then it definitely has no way to exceed the receiver's buffer as the window size is always less than or equal to the buffer size. On the other hand, for urgent messages, the sender CAN send it in even although the receiver's buffer is full.
