2012 Management

Question Papers of Data Communications and Networking

Question Papers of Data Communications and Networking

Data Communications and Networking
BCA 2nd SEM
Max time: 3 hrs

PART-A
1. Frequency of failure and network recovery time after a failure are the measures of the ___of a network.
2. In a mesh topology, if there are n devices in a network, what is the minimum number of ports that must be provided in each device?
3. Decryption and encryption of data are the responsibility of __layer.
4. Given two sine waves A and B, if the frequency of A is twice that of B, then the period of B is __ that of A.
5. In a frequency-domain plot, the vertical axis measures the ____.
6. ASK, PSK, FSK AND QAM are examples of ______encoding.
7. RZ encoding involves ______levels of signal amplitude.
8. The encoding method specified in EIA – 232 standards is __
9. What is the object of trellis coding?
10. It a satellite is in geosynchronous orbit, it completes one orbit in _____
11. Given the following information: FDM multiplexing, five devices, each requiring 4000 Hz, 200 Hz guard band for each device. What is the minimum bandwidth for the path?
12. In CRC, if the data unit is 111111, the divisor is 1010, what is the dividend at transmitter?
13. Give the hamming code for the bit sequence 11011011.
14. What is the purpose of flow control?
15. Expand ARQ.
16. Frame acknowledgement, flow control and error control are function of __of in HDLC protocol.
17. When data and acknowledgement are sent on the same frame, this is called _____
18. What is difference between 10 BASE2 AND 10 BASE 5?
19. DQDB is an acronym for _______.
20. Which ISDN plane is associated with signalling and D channel?
21. X.25 protocol requires error checking at _______layer (s).
22. What is the cell size of ATM protol ?
23. If there are five routers and six networks in an internet work, how many link state databases are there?
24. Error control is needed at the transport layer because of potential errors occurring _____
25. DNS can obtain the ______ of a host if domain name is known and vice versa.

PART – B

UNIT-I
2. A) What are the advantages of a multipoint connection point to point? 3m
b) List out the responsibilities of the transport layer in OSI mode. 4m
c) What is the difference between bit rate and baud rate? Give an example where they are different. 3m
OR
3. Draw the wave forms for 010011110 in each of the following methods:
i) Unipolar ii) NRZ-L and NRZ-I iii) RZ iv) Manchesterv) Different Manchester.

UNIT –II
4. A) how does the X-21 standard handle control signals? 5m
b) Discuss the operation of cellular telephony. 5m
OR
5 Explain the three different types of errors that occurs during the transmission and methods of error correction.

UNIT -III
6 a) Explain CSMA/CD and its use. 6m
b) Why and where is flow control needed? What are the parameters to be considered for flow control? 4m
OR
7 a) Compare Ethernet, Token ring and FDDI in terms of occurs method. Signaling and error control. 6m
b) List the advantages of packet switching over circuit switching for data transmission. 4m

UNIT -IV
8. A) What does the X.25 provide in the area of error control/detection ? 5m
b) List out the services provided by ISDN. 5m
OR
9 a) How is flow control handled in frame relay? 5m
b) Draw a SONET network using all of the following devices: Three STS multiplexers, two add/drop multiplexers and five regenerators. Label all lines, sections and paths 5m

UNIT-V
10. List and explain the application layer protocols of TCP/IP. 10M
OR
11. A) List out the functions of presentation layer. 4m
b) Explain the functions of four internetworking devices: repeaters, bridges, routers and gateways. 6m