Osmania University (OU) 2000 B.C.A Computer Application Data Communications and Networking - Question Paper

Data Communications and Networking
BCA second sem
Max time: three 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 given in every device ?

3. Decryption and encryption of data are the responsibility of __layer.

4. provided 2 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 standard is __

9. What is the object of trellis coding ?

10. It a satellite is in geosynchronous orbit, it completes 1 orbit in _____

11. provided the subsequent info : FDM multiplexing, 5 devices, every requiring 4000 Hz, 200 Hz guard band for every 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. provide 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 fault control are function of __of in HDLC protocol.

17. When data and acknowledgement are sent on the identical frame, this is called _____

18. What is difference ranging from 10 BASE2 AND 10 BASE five ?

19. DQDB is an acronym for _______.

20. Which ISDN plane is associated with signalling and D channel ?

21. X.25 protocol require fault checking at _______layer (s).

22. What is the cell size of ATM protol ?

23. If there are 5 routers and 6 networks in an internetwork, how many link state databases are there ?

24. fault control is needed at the transport layer because of potential errors occurring _____

25. DNS can find the ______ of a host if domain name is known and vice versa.

PART - B

UNIT-I

2. a) elaborate 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 ranging from bit rate and baud rate ? provide an example where they are various. 3m

OR

3. Draw the wave forms for 010011110 in every of the subsequent methods :

i) Unipolar ii) NRZ-L and NRZ-I iii) RZ iv) Manchesterv) various 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 discuss the 3 various kinds of errors that occurs during the transmission and methods of fault correction.

UNIT -III

6 a) discuss CSMA/CD and it's use. 6m

b) Why and where is flow control needed ? elaborate 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 fault 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 give in the area of fault control/detection ? 5m

b) List out the services given by ISDN. 5m

OR

9 a) How is flow control handled in frame relay ? 5m

b) Draw a SONET network using all of the subsequent devices : 3 STS multiplexers, 2 add/drop multiplexers and 5 regenerators. tag all lines, parts and paths 5m

UNIT-V

10. List and discuss the application layer protocols of TCP/IP. 10M

OR

11. a) List out the functions of presentation layer. 4m

b) discuss the functions of 4 internetworking devices : repeaters ,bridges, routers and gateways. 6m

Earning:   Approval pending.