Transport Layer Protocol
Q21.
Consider a TCP connection between a client and a server with the following specifications; the round trip time is 6 ms, the size of the receiver advertised window is 50 KB, slow-start threshold at the client is 32 KB, and the maximum segment size is 2 KB. The connection is established at time t=0. Assume that there are no timeouts and errors during transmission. Then the size of the congestion window (in KB) at time t+60 ms after all acknowledgements are processed is _______Q22.
The three way handshake for TCP connection establishment is shown below. Which of the following statements are TRUE? S1: Loss of SYN + ACK from the server will not establish a connection S2: Loss of ACK from the client cannot establish the connection S3: The server moves LISTEN \to SYN\_RCVD \to SYN\_SENT \to ESTABLISHED in the state machine on no packet loss S4: The server moves LISTEN \to SYN\_RCVD \to ESTABLISHED in the state machine on no packet lossQ23.
Consider the data transfer using TCP over a 1 Gbps link. Assuming that the maximum segment lifetime (MSL) is set to 60 seconds, the minimum number of bits required for the sequence number field of the TCP header, to prevent the sequence number space from wrapping around during the MSL isQ24.
Consider two hosts P and Q connected through a router R. The maximum transfer unit (MTU) value of the link between P and R is 1500 bytes, and between R and Q is 820 bytes. A TCP segment of size 1400 bytes was transferred from P to Q through R, with IP identification value as 0x1234. Assume that the IP header size is 20 bytes. Further, the packet is allowed to be fragmented, i.e., Don't Fragment (DF) flag in the IP header is not set by P. Which of the following statements is/are correct?[MSQ]Q25.
Consider the three-way handshake mechanism followed during TCP connection establishment between hosts P and Q. Let X and Y be two random 32-bit starting sequence numbers chosen by P and Q respectively. Suppose P sends a TCP connection request message to Q with a TCP segment having SYN bit =1, SEQ number =X, and ACK bit =0. Suppose Q accepts the connection request. Which one of the following choices represents the information present in the TCP segment header that is sent by Q to P?Q27.
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 course of the TCP connection. IV. The number of unacknowledged bytes at the sender is always less than or equal to the advertised window.Q28.
In the slow start phase of the TCP congestion control algorithm, the size of the congestion windowQ29.
Consider a TCP connection in a state where there are no outstanding ACKs. The sender sends two segments back to back. The sequence numbers of the first and second segments are 230 and 290 respectively. The first segment was lost, but the second segment was received correctly by the receiver. Let X be the amount of data carried in the first segment (in bytes), and Y be the ACK number sent by the receiver. The values of X and Y (in that order) are