Transport Layer

Single correct

• AThe client and server use a two-way handshake mechanism before the start of data transmission
• BThe server cannot initiate closing of the connection before the client initiates closing of the connection
• CThe TCP connection is half-duplex
• DThe client and server can initiate closing of the connection at the same time

Single correct

• A$9 \le t < 10$
• B$10 \le t < 11$
• C$11 \le t < 12$
• D$12 \le t < 13$

Numerical answer

One or more correct

• AP3: SYN = 1, ACK = 1
• BP2: SYN = 1, ACK = 1
• CP2: SYN = 0, ACK = 1
• DP1: SYN = 1

Single correct

• ABoth (i) and (ii) are TRUE
• B(i) is TRUE and (ii) is FALSE
• C(i) is FALSE and (ii) is TRUE
• DBoth (i) and (ii) are FALSE

Single correct

• A(iv), (ii), (iii), (i)
• B(ii), (iv), (iii), (i)
• C(ii), (iv), (i), (iii)
• D(iv), (ii), (i), (iii)

One or more correct

• AThe sequence number $N_P$ is chosen randomly by P
• BThe sequence number $N_P$ is always 0 for a new connection
• CThe acknowledgement number $N_Q$ is equal to $N_P$
• DThe acknowledgement number $N_Q$ is equal to $N_P + 1$

Numerical answer

One or more correct

• A30 bits
• B32 bits
• C34 bits
• D36 bits

Answer key coming soon

Numerical answer

Answer key coming soon

One or more correct

• AIf the client was waiting to receive a packet, it may wait indefinitely.
• BThe TCP server application on $S$ can listen on $P$ after reboot.
• CIf the client sends a packet after the server reboot, it will receive a RST segment.
• DIf the client sends a packet after the server reboot, it will receive a FIN segment.

Answer key coming soon

One or more correct

• ATwo fragments are created at $R$ and the IP datagram size carrying the second fragment is 620 bytes.
• BIf the second fragment is lost, $R$ will resend the fragment with the IP identification value 0x1234.
• CIf the second fragment is lost, $P$ is required to resend the whole TCP segment.
• DTCP destination port can be determined by analysing *only* the second fragment.

Answer key coming soon

Single correct

• ASYN bit = 1, SEQ number = X+1, ACK bit = 0, ACK number = Y, FIN bit = 0
• BSYN bit = 0, SEQ number = X+1, ACK bit = 0, ACK number = Y, FIN bit = 1
• CSYN bit = 1, SEQ number = Y, ACK bit = 1, ACK number = X+1, FIN bit = 0
• DSYN bit = 1, SEQ number = Y, ACK bit = 1, ACK number = X, FIN bit = 0

Answer key coming soon

Numerical answer

Answer key coming soon

Numerical answer

Answer key coming soon

Single correct

• AOnly (ii) and (iii) are true
• BOnly (i) and (iii) are true
• COnly (iv) is true
• DOnly (i) and (iv) are true

Numerical answer

Single correct

• ALAST-ACK
• BTIME-WAIT
• CFIN-WAIT-1
• DFIN-WAIT-2

Answer key coming soon

Single correct

• AI only
• BII only
• CBoth I and II
• DNeither I nor II

Answer key coming soon

Numerical answer

Answer key coming soon