Misc Topics in Computer Networks

Question 41

Consider the following statements about the timeout value used in TCP. i. The timeout value is set to the RTT (Round Trip Time) measured during TCP connection establishment for the entire duration of the connection. ii. Appropriate RTT estimation algorithm is used to set the timeout value of a TCP connection. iii. Timeout value is set to twice the propagation delay from the sender to the receiver. Which of the following choices hold?

• (i) is false, but (ii) and (iii) are true
• (i) and (iii) are false, but (ii) is title
• (i) and (ii) are false, but (iii) is true
• (i), (ii) and (iii) are false

Question 42

How many bytes of data can be sent in 15 seconds over a serial link with baud rate of 9600 in asynchronous mode with odd parity and two stop bits in the frame?

• 10,000 bytes
• 12,000 bytes
• 15,000 bytes
• 27,000 bytes

Question 43

A firewall is to be configured to allow hosts in a private network to freely open TCP connections and send packets on open connections. However, it will only allow external hosts to send packets on existing open TCP connections or connections that are being opened (by internal hosts) but not allow them to open TCP connections to hosts in the private network. To achieve this the minimum capability of the firewall should be that of

• A combinational circuit
• A finite automaton
• A pushdown automaton with one stack
• A pushdown automaton with two stacks

Question 44

An email contains a textual birthday greeting, a picture of a cake and a song. The order is not important. What is the content-type?

• Multipart/mixed
• Multipart/parallel
• Multipart/digest
• Multipart/alternative

Question 45

Phase transition for each bit are used in

• Amplitude modulation
• Carrier modulation
• Manchester encoding
• NRZ encoding

Question 46

In networking, UTP stands for

• Unshielded T-connector port
• Unshielded twisted pair
• Unshielded terminating pair
• Unshielded transmission process

Question 47

Data is transmitted continuously at 2.048 Mbps rate for 10 hours and received 512 bits errors. What is the bit error rate?

• 6.9 e-9

• 6.9 e-6

• 69 e-9

• 4 e-9

Question 48

The IEEE standard for WiMax technology is

• IEEE 802.16
• IEEE 802.36
• IEEE 812.16
• IEEE 806.16

Question 49

A T-switch is used to

• Control how messages are passed between computers
• Echo every character that is received
• Transmit characters one at a time
• Rearrange the connections between computing equipments

Question 50

Match the security protocols with the layers they are used in and choose the correct code - 


[Tex]\begin{array}{ll} List-1 & List-2\\ A. TLS & 1. Physical Layer\\ B. WEP & 2. Link Layer\\ C. PGP & 3. Network Layer\\ D. IPsec & 4. Transport Layer\\ & 5. Application Layer\\ \end{array}[/Tex]




Codes- 
[Tex] \begin{array}{lllll} & A & B & C & D\\ (a) & 2 & 5 & 1 & 3\\ (b) & 5 & 2 & 3 & 2\\ (c) & 4 & 2 & 5 & 3\\ (d) & 5 & 2 & 4 & 3\\ \end{array}[/Tex]

• (d)
  

• (c)
  

• (b)
  

• (a)