Test Series Question

Question

Consider the following statements:
S₁: The size of TCP receiver window never change throughout the duration of the connection.
S₂: Suppose host A is sending a large file to host B over a TCP connection. The number of unacknowledged bytes that host A send cannot exceed the size of the advertised receiver buffer.
Which of the following is correct?

1. S₁ is true but S₂ is false

2.  S₁ is false but S₂ is true

3. Both S₁ and S₂ is true

4. Neither S₁ nor S₂ is true

Answer 1

1.  Receiver window is used to give the sender an idea of how much free buffer space is available at
the receiver. So, as the receiver buffer changed receiver window also change.

2. TCP does not allow to host to send more data than receiver buffer requirement which restrict the
data overflow.

So, S₁ is false but S₂ is true

Comments

I have doubt

how option A) can be false?

" The size of TCP receiver window never change throughout the duration of the connection. "

during a connection means the time of connection establishment receiver window size same as sender window size. How it can be different?

Plz elaborate more

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receiver window is used to give the sender an idea of how much free buffer space is available at the receiver. Thus as the amount of unacknowledged TCP data varies the receiver window also changes.

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but is it in duration of one connection establishment?

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 srestha : Throughout the connection means starting with synchronization to finalizing the connection.But in between, there can be many flow levels which will result in the change of TCP receiver window.

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yes this is right

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@saxena0612

In the starting and finalishing the connection,

1)SYN  packets send

2)SYN+ACK packets reqeived

3)ACK received

Here 3 level handshakes completed

Is any more flow level there, where receiver window size can change?

Answer 2

option 2

S1 is false bcz  the size of the receiver's buffer that's never changed. Rcver Window is the part of the receiver's buffer that's changing all the time depending on the processing capability at the receiver's side and the network traffic.

S2 is true bcz when we send large file from advertised receiver buffer then it leads to be overflow. So file can not exceed the size of advertised recover buffer.