Computer Networks

Q11. A client process P needs to make a TCP connection to a server Process S. Consider the following situation; the server process S executes a socket (), a bind() and a listen () system call in that order, following which it is preempted. Subsequently, the client Process P executes a socket () system call followed by connect () system call to connect to the server process S. The server process has not executed any accept() system call. Which one of the following events could take place? (Gate 2008)

1. connect ( ) system call returns successfully
2. connect ( ) system call blocks
3. connect ( ) system call returns an error
4. connect ( ) system call results in a core dump

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Q12. A computer on a 10Mbps network is regulated by a token bucket. The token bucket is filled at a rate of 2Mbps. It is initially filled to capacity with 16Megabits. What is the maximum duration for which the computer can transmit at the full 10Mbps? (Gate 2008)

1. 1.6 seconds
2. 2 seconds
3. 5 seconds
4. 8 seconds

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Q13. If a class B network on the Internet has a subnet mask of 255.255.248.0, what is the maximum number of hosts per subnet?(Gate 2008)

1. 1022
2. 1023
3. 2046
4. 2047

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Q14.In the slow start phase of the TCP congesting control algorithm, the size of the congestion window(Gate 2008)

1. Does not increase
2. Increases linearly
3. Increases quadratically
4. Increases exponentially

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Q15.What is the maximum size of data that the application layer can pass on to the TCP layer below?(Gate 2008)

1. Any size
2. 2¹⁶ bytes-size of TCP header
3. 2¹⁶ bytes
4. 1500 bytes

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Q16.Match the following:(Gate 2007)

Protocol	Layers
P. SMTP	1. Application Layer
Q. BGP	2. Transport Layer
R. TCP	3. Data Link Layer
S. PPP	4. Network Layer
	5. Physical Layer

1. P-2,Q-1,R-3,S-5
2. P-1,Q-4,R-2,S-3
3. P-1,Q-4,R-2,S-5
4. P-2,Q-4,R-1,S-3

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Q17. The distance between the two stations M and N is L kilometers. All frames are K bits long. The propagation delay per kilometer is t seconds Let R bits/second be the channel capacity. Assuming that the processing delay is negligible, the minimum number of bits for the sequence number field in a frame for maximum utilization, when the sliding window protocol is used, is; (Gate 2007)

1. 
2. 
3. 
4. 

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Q18. The message 11001001 is to be transmitted using the CRC polynomial x 1 3 + to protect it from errors. The message that should be transmitted is:(Gate 2007)

1. 11001001000
2. 11001001011
3. 11001010
4. 110010010011

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Q19. The address of a class B host is to be split into subnets with a 6-bit subnet number. What are the maximum number of subnets and the maximum number of hosts in each subnet? (Gate 2007)

1. 62 subnets and 262142 hosts
2. 64 subnets and 262142 hosts
3. 62 subnets and 1022 hosts
4. 64 subnets and 1024 hosts

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Q20. In a token ring network, the transmission speed is 10 bps and the ropagation speed is 200 metres/μs . The 1-bit delay in this network is equivalent to; (Gate 2007)

1. 500 metres of cable
2. 200 metres of cable
3. 20 metres of cable
4. 50 metres of cable

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