Transport Layer

Question 51

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?

• SYN bit =1, SEQ number =X+1, ACK bit =0, ACK number =Y, FIN bit =0
• SYN bit =0, SEQ number =X+1, ACK bit =0, ACK number =Y, FIN bit =1
• SYN bit =1, SEQ number =Y, ACK bit =1, ACK number =X+1, FIN bit =0
• SYN bit =1, SEQ number =Y, ACK bit =1, ACK number =X, FIN bit =0

Question 52

Match the following:

• (1)

• (2)

• (3)

• (4)

Question 53

A TCP server application is programmed to listen on port number P on host S. A TCP client is connected to the TCP server over the network. Consider that while the TCP connection was active, the server machine S crashed and rebooted. Assume that the client does not use the TCP keepalive timer. Which of the following behaviors is/are possible?

• If the client was waiting to receive a packet, it may wait indefinitely
• The TCP server application on S can listen on P after reboot
• If the client sends a packet after the server reboot, it will receive a RST segment
• If the client sends a packet after the server reboot, it will receive a FIN segment

Question 54

SSL is not responsible for

• Mutual authentication of client & server
• Secret communication
• Data Integrity protection
• Error detection and correction

Question 55

Silly Window Syndrome is related to

• Error during transmission

• File transfer protocol

• Degrade in TCP performance

• Interface problem

Question 56

Which of the following control fields in TCP header is used to specify whether the sender has no more data to transmit?

• FIN
• RST
• SYN
• PSH

Question 57

Four channels are multiplexed using TDM. If each channel sends 100 bytes/second and we multiplex 1 byte per channel, then the bit rate for the link is __________.

• 400 bps
• 800 bps
• 1600 bps
• 3200 bps

Question 58

Optical fiber uses reflection to guide light through a channel, in which angle of incidence is ________ the critical angle.

• equal to
• less than
• greater than
• less than or equal to